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snapshots/jotego_jtcores_pr1100/modules/jtframe/asm/z80/Makefile

@@ -0,0 +1,5 @@
+jtTinyBasic.o: jtTinyBasic.asm
+	z80asm jtTinyBasic.asm -o jtTinyBasic.o -l 2> jtTinyBasic.lst
+
+clean:
+	rm -f jtTinyBasic.o jtTinyBasic.lst

snapshots/jotego_jtcores_pr1100/modules/jtframe/asm/z80/TinyBasic_2.0g.asm

@@ -0,0 +1,1780 @@
+;*************************************************************
+;
+;                 TINY BASIC FOR ZILOG Z80
+;                       VERSION 2.0
+;                     BY LI-CHEN WANG
+;
+;                  MODIFIED AND TRANSLATED
+;                    TO INTEL MNEMONICS
+;                     BY ROGER RAUSKOLB
+;                      10 OCTOBER,1976
+;
+;                  MODIFIED AND TRANSLATED
+;                    TO ZILOG MNEMONICS
+;                      BY DOUG GABBARD
+;            www.retrodepot.net
+;
+;           RELEASED TO THE PUBLIC
+;                      10 OCTOBER,2017
+;                  YEAH, 41 YEARS LATER....
+;
+;                         @COPYLEFT
+;                   ALL WRONGS RESERVED
+;
+;*************************************************************
+; This code is derived from the original 8080 Tiny Basic.
+; It was first compiled in 8080 Mnemonics, then disassembled
+; into Zilog Mnemonics.  And then checked against the original
+; to ensure accuracy.  It was then partially enhanced with z80
+; specific code. And once done, it was then modified to work
+; with the G80-S Micro Computer. However, that portion of the
+; code has been left out in order to make this code a little
+; more portable.  There are only three routines that one needs
+; to write, and specifing the serial port's I/O address, in
+; order to make this version work with your own DIY computer.
+; Those routines can be found at the end of the source code.
+;
+; I hope you find good use for this relic. However, I would
+; ask that if you do find use for it, please put a reference
+; to me in your work. And please, distribute freely.
+;*************************************************************
+
+SerialPort: EQU 00H     ;This is for your I/0
+
+
+SPACE:          EQU     020H            ; Space
+TAB:            EQU     09H             ; HORIZONTAL TAB
+CTRLC:          EQU     03H             ; Control "C"
+CTRLG:          EQU     07H             ; Control "G"
+BKSP:           EQU     08H             ; Back space
+LF:             EQU     0AH             ; Line feed
+CS:             EQU     0CH             ; Clear screen
+CR:             EQU     0DH             ; Carriage return
+CTRLO:          EQU     0FH             ; Control "O"
+CTRLQ:          EQU     011H            ; Control "Q"
+CTRLR:          EQU     012H            ; Control "R"
+CTRLS:          EQU     013H            ; Control "S"
+CTRLU:          EQU     015H            ; Control "U"
+ESC:            EQU     01BH            ; Escape
+DEL:            EQU     07FH            ; Delete
+
+STACK:          EQU     0FFFFH          ; STACK
+OCSW:           EQU     08000H          ;SWITCH FOR OUTPUT
+CURRNT:         EQU     OCSW+1          ;POINTS FOR OUTPUT
+STKGOS:         EQU     OCSW+3          ;SAVES SP IN 'GOSUB'
+VARNXT:         EQU     OCSW+5          ;TEMP STORAGE
+STKINP:         EQU     OCSW+7          ;SAVES SP IN 'INPUT'
+LOPVAR:         EQU     OCSW+9          ;'FOR' LOOP SAVE AREA
+LOPINC:         EQU     OCSW+11         ;INCREMENT
+LOPLMT:         EQU     OCSW+13         ;LIMIT
+LOPLN:          EQU     OCSW+15         ;LINE NUMBER
+LOPPT:          EQU     OCSW+17         ;TEXT POINTER
+RANPNT:         EQU     OCSW+19         ;RANDOM NUMBER POINTER
+TXTUNF:         EQU     OCSW+21         ;->UNFILLED TEXT AREA
+TXTBGN:         EQU     OCSW+23         ;TEXT SAVE AREA BEGINS
+
+TXTEND:         EQU     0FF00H          ;TEXT SAVE AREA ENDS
+
+
+;*************************************************************
+; *** ZERO PAGE SUBROUTINES ***
+;
+; THE Z80 INSTRUCTION SET ALLOWS FOR 8 ROUTINES IN LOW MEMORY
+; THAT MAY BE CALLED BY RST 00H, 08H, 10H, 18H, 20H, 28H, 30H,
+; AND 38H.  THIS IS A ONE BYTE INSTRUCTION, AND IS FUNCTIONALLY
+; SIMILAR TO THE THREE BYTE INSTRUCTION 'CALL XXXX'. TINY BASIC
+; WILL USE THE RST INSTRUCTION FOR THE 7 MOST FREQUENTLY USED
+; SUBROUTINES. TWO OTHER SUBROUTINES (CRLF & TSTNUM) ARE ALSO
+; IN THIS SECTION. THEY CAN BE REACHED WITH 'CALL'.
+;*************************************************************
+
+DWA:    MACRO WHERE
+        DB   (WHERE >> 8) + 128
+        DB   WHERE & 0FFH
+        ENDM
+
+        ORG  0000H
+
+START:
+        LD SP,STACK                     ;*** COLD START ***
+        LD A,0FFH
+        JP INIT
+
+RST08:  EX (SP),HL                      ;*** TSTC OR RST 08H ***
+        RST 28H                         ;IGNORE BLANKS AND
+        CP (HL)                         ;TEST CHARACTER
+        JP TC1                          ;REST OF THIS IS AT TC1
+
+CRLF:
+        LD A,CR                         ;*** CRLF ***
+
+RST10:  PUSH AF                         ;*** OUTC OR RST 10H ***
+        LD A,(OCSW)                     ;PRINT CHARACTER ONLY
+        OR A                            ;IF OCSW SWITCH IS ON
+        JP OUTC             ;REST OF THIS AT OUTC
+
+RST18:  CALL EXPR2                      ;*** EXPR OR RST 18H ***
+        PUSH HL                         ;EVALUATE AN EXPRESSION
+        JP EXPR1                        ;REST OF IT AT EXPR1
+        DB 'W'
+
+RST20:  LD A,H                          ;*** COMP OR RST 20H ***
+        CP D                            ;COMPARE HL WITH DE
+        RET NZ                          ;RETURN CORRECT C AND
+        LD A,L                          ;Z FLAGS
+        CP E                            ;BUT OLD A IS LOST
+        RET
+        DB 'AN'
+
+SS1:
+RST28:  LD A,(DE)                       ;*** IGNBLK/RST 28H ***
+        CP 20H                          ;IGNORE BLANKS
+        RET NZ                          ;IN TEXT (WHERE DE->)
+        INC DE                          ;AND RETURN THE FIRST
+        JP SS1                          ;NON-BLANK CHAR. IN A
+
+RST30:  POP AF                          ;*** FINISH/RST 30H ***
+        CALL FIN                        ;CHECK END OF COMMAND
+        JP QWHAT                        ;PRINT "WHAT?" IF WRONG
+        DB 'G'
+
+RST38:  RST 28H                         ;*** TSTV OR RST 38H ***
+        SUB 40H                         ;TEST VARIABLES
+        RET C                           ;C:NOT A VARIABLE
+        JR NZ,TV1                       ;NOT "@" ARRAY
+        INC DE                          ;IT IS THE "@" ARRAY
+        CALL PARN                       ;@ SHOULD BE FOLLOWED
+        ADD HL,HL                       ;BY (EXPR) AS ITS INDEX
+        JR C,QHOW                       ;IS INDEX TOO BIG?
+        PUSH DE                         ;WILL IT OVERWRITE
+        EX DE,HL                        ;TEXT?
+        CALL SIZE                       ;FIND SIZE OF FREE
+        RST 20H                         ;AND CHECK THAT
+        JP C,ASORRY                     ;IF SO, SAY "SORRY"
+        LD HL,VARBGN                    ;IF NOT GET ADDRESS
+        CALL SUBDE                      ;OF @(EXPR) AND PUT IT
+        POP DE                          ;IN HL
+        RET                             ;C FLAG IS CLEARED
+
+TV1:
+        CP 1BH                          ;NOT @, IS IT A TO Z?
+        CCF                             ;IF NOT RETURN C FLAG
+        RET C
+        INC DE                          ;IF A THROUGH Z
+        LD HL,VARBGN                    ;COMPUTE ADDRESS OF
+        RLCA                            ;THAT VARIABLE
+        ADD A,L                         ;AND RETURN IT IN HL
+        LD L,A                          ;WITH C FLAG CLEARED
+        LD A,00H
+        ADC A,H
+        LD H,A
+        RET
+
+TC1:
+        INC HL                          ;COMPARE THE BYTE THAT
+        JR Z,TC2                        ;FOLLOWS THE RST INST.
+        PUSH BC                         ;WITH THE TEXT (DE->)
+        LD C,(HL)                       ;IF NOT =, ADD THE 2ND
+        LD B,00H                        ;BYTE THAT FOLLOWS THE
+        ADD HL,BC                       ;RST TO THE OLD PC
+        POP BC                          ;I.E., DO A RELATIVE
+        DEC DE                          ;JUMP IF NOT =
+
+TC2:
+        INC DE                          ;IF =, SKIP THOSE BYTES
+        INC HL                          ;AND CONTINUE
+        EX (SP),HL
+        RET
+
+TSTNUM:
+        LD HL,0000H                     ;*** TSTNUM ***
+        LD B,H                          ;TEST IF THE TEXT IS
+        RST 28H                         ;A NUMBER
+
+TN1:
+        CP 30H                          ;IF NOT, RETURN 0 IN
+        RET C                           ;B AND HL
+        CP 3AH                          ;IF NUMBERS, CONVERT
+        RET NC                          ;TO BINARY IN HL AND
+        LD A,0F0H                       ;SET B TO # OF DIGITS
+        AND H                           ;IF H>255, THERE IS NO
+        JR NZ,QHOW                      ;ROOM FOR NEXT DIGIT
+        INC B                           ;B COUNTS # OF DIGITS
+        PUSH BC
+        LD B,H                          ;HL=10*HL+(NEW DIGIT)
+        LD C,L
+        ADD HL,HL                       ;WHERE 10* IS DONE BY
+        ADD HL,HL                       ;SHIFT AND ADD
+        ADD HL,BC
+        ADD HL,HL
+        LD A,(DE)                       ;AND (DIGIT) IS FROM
+        INC DE                          ;STRIPPING THE ASCII
+        AND 0FH                         ;CODE
+        ADD A,L
+        LD L,A
+        LD A,00H
+        ADC A,H
+        LD H,A
+        POP BC
+        LD A,(DE)                       ;DO THIS DIGIT AFTER
+        JP P,TN1                        ;DIGIT. S SAYS OVERFLOW
+
+QHOW:
+        PUSH DE                         ;*** ERROR "HOW?" ***
+AHOW:
+        LD DE,HOW
+        JP ERROR_ROUTINE
+
+
+HOW:    DB "HOW?",CR
+OK:     DB "OK",CR
+WHAT:   DB "WHAT?",CR
+SORRY:  DB "SORRY",CR
+
+;*************************************************************
+;
+; *** MAIN ***
+;
+; THIS IS THE MAIN LOOP THAT COLLECTS THE TINY BASIC PROGRAM
+; AND STORES IT IN THE MEMORY.
+;
+; AT START, IT PRINTS OUT "(CR)OK(CR)", AND INITIALIZES THE
+; STACK AND SOME OTHER INTERNAL VARIABLES.  THEN IT PROMPTS
+; ">" AND READS A LINE.  IF THE LINE STARTS WITH A NON-ZERO
+; NUMBER, THIS NUMBER IS THE LINE NUMBER.  THE LINE NUMBER
+; (IN 16 BIT BINARY) AND THE REST OF THE LINE (INCLUDING CR)
+; IS STORED IN THE MEMORY.  IF A LINE WITH THE SAME LINE
+; NUMBER IS ALREADY THERE, IT IS REPLACED BY THE NEW ONE.  IF
+; THE REST OF THE LINE CONSISTS OF A CR ONLY, IT IS NOT STORED
+; AND ANY EXISTING LINE WITH THE SAME LINE NUMBER IS DELETED.
+;
+; AFTER A LINE IS INSERTED, REPLACED, OR DELETED, THE PROGRAM
+; LOOPS BACK AND ASKS FOR ANOTHER LINE.  THIS LOOP WILL BE
+; TERMINATED WHEN IT READS A LINE WITH ZERO OR NO LINE
+; NUMBER; AND CONTROL IS TRANSFERED TO "DIRECT".
+;
+; TINY BASIC PROGRAM SAVE AREA STARTS AT THE MEMORY LOCATION
+; LABELED "TXTBGN" AND ENDS AT "TXTEND".  WE ALWAYS FILL THIS
+; AREA STARTING AT "TXTBGN", THE UNFILLED PORTION IS POINTED
+; BY THE CONTENT OF A MEMORY LOCATION LABELED "TXTUNF".
+;
+; THE MEMORY LOCATION "CURRNT" POINTS TO THE LINE NUMBER
+; THAT IS CURRENTLY BEING INTERPRETED.  WHILE WE ARE IN
+; THIS LOOP OR WHILE WE ARE INTERPRETING A DIRECT COMMAND
+; (SEE NEXT SECTION). "CURRNT" SHOULD POINT TO A 0.
+;*************************************************************
+
+RSTART:
+        LD SP,STACK
+
+ST1:
+        CALL CRLF                       ;AND JUMP TO HERE
+        LD DE,OK                        ;DE->STRING
+        SUB A                           ;A=0
+        CALL PRTSTG                     ;PRINT STRING UNTIL CR
+        LD HL,ST2+1                     ;LITERAL 0
+        LD (CURRNT),HL                  ;CURRENT->LINE # = 0
+
+ST2:
+        LD HL,0000H
+        LD (LOPVAR),HL
+        LD (STKGOS),HL
+
+ST3:
+        LD A,'>'                        ;PROMPT '>' AND
+        CALL GETLN                      ;READ A LINE
+        PUSH DE                         ;DE->END OF LINE
+        LD DE,BUFFER                    ;DE->BEGINNING OF LINE
+        CALL TSTNUM                     ;TEST IF IT IS A NUMBER
+        RST 28H
+        LD A,H                          ;HL=VALUE OF THE # OR
+        OR L                            ;0 IF NO # WAS FOUND
+        POP BC                          ;BC->END OF LINE
+        JP Z,DIRECT
+        DEC DE                          ;BACKUP DE AND SAVE
+        LD A,H                          ;VALUE OF LINE # THERE
+        LD (DE),A
+        DEC DE
+        LD A,L
+        LD (DE),A
+        PUSH BC                         ;BC,DE->BEGIN, END
+        PUSH DE
+        LD A,C
+        SUB E
+
+        PUSH AF                         ;A=# OF BYTES IN LINE
+        CALL FNDLN                      ;FIND THIS LINE IN SAVE
+        PUSH DE                         ;AREA, DE->SAVE AREA
+        JR NZ,ST4                       ;NZ:NOT FOUND, INSERT
+        PUSH DE                         ;Z:FOUND, DELETE IT
+        CALL FNDNXT                     ;FIND NEXT LINE
+                                        ;DE->NEXT LINE
+        POP BC                          ;BC->LINE TO BE DELETED
+        LD HL,(TXTUNF)                  ;HL->UNFILLED SAVE AREA
+        CALL MVUP                       ;MOVE UP TO DELETE
+        LD H,B                          ;TXTUNF->UNFILLED ARA
+        LD L,C
+        LD (TXTUNF),HL                  ;UPDATE
+
+ST4:
+        POP BC                          ;GET READY TO INSERT
+        LD HL,(TXTUNF)                  ;BUT FIRST CHECK IF
+        POP AF                          ;THE LENGTH OF NEW LINE
+        PUSH HL                         ;IS 3 (LINE # AND CR)
+        CP 03H                          ;THEN DO NOT INSERT
+        JR Z,RSTART                     ;MUST CLEAR THE STACK
+        ADD A,L                         ;COMPUTE NEW TXTUNF
+        LD L,A
+        LD A,00H
+        ADC A,H
+        LD H,A                          ;HL->NEW UNFILLED AREA
+        LD DE,TXTEND                    ;CHECK TO SEE IF THERE
+        RST 20H                         ;IS ENOUGH SPACE
+        JP NC,QSORRY                    ;SORRY, NO ROOM FOR IT
+        LD (TXTUNF),HL                  ;OK, UPDATE TXTUNF
+        POP DE                          ;DE->OLD UNFILLED AREA
+        CALL MVDOWN
+        POP DE                          ;DE->BEGIN, HL->END
+        POP HL
+        CALL MVUP                       ;MOVE NEW LINE TO SAVE
+        JR ST3                          ;AREA
+
+;*************************************************************
+;
+; WHAT FOLLOWS IS THE CODE TO EXECUTE DIRECT AND STATEMENT
+; COMMANDS.  CONTROL IS TRANSFERED TO THESE POINTS VIA THE
+; COMMAND TABLE LOOKUP CODE OF 'DIRECT' AND 'EXEC' IN LAST
+; SECTION.  AFTER THE COMMAND IS EXECUTED, CONTROL IS
+; TRANSFERED TO OTHERS SECTIONS AS FOLLOWS:
+;
+; FOR 'LIST', 'NEW', AND 'STOP': GO BACK TO 'RSTART'
+; FOR 'RUN': GO EXECUTE THE FIRST STORED LINE IF ANY, ELSE
+; GO BACK TO 'RSTART'.
+; FOR 'GOTO' AND 'GOSUB': GO EXECUTE THE TARGET LINE.
+; FOR 'RETURN' AND 'NEXT': GO BACK TO SAVED RETURN LINE.
+; FOR ALL OTHERS: IF 'CURRENT' -> 0, GO TO 'RSTART', ELSE
+; GO EXECUTE NEXT COMMAND.  (THIS IS DONE IN 'FINISH'.)
+;*************************************************************
+;
+; *** NEW *** STOP *** RUN (& FRIENDS) *** & GOTO ***
+;
+; 'NEW(CR)' SETS 'TXTUNF' TO POINT TO 'TXTBGN'
+;
+; 'STOP(CR)' GOES BACK TO 'RSTART'
+;
+; 'RUN(CR)' FINDS THE FIRST STORED LINE, STORE ITS ADDRESS (IN
+; 'CURRENT'), AND START EXECUTE IT.  NOTE THAT ONLY THOSE
+; COMMANDS IN TAB2 ARE LEGAL FOR STORED PROGRAM.
+;
+; THERE ARE 3 MORE ENTRIES IN 'RUN':
+; 'RUNNXL' FINDS NEXT LINE, STORES ITS ADDR. AND EXECUTES IT.
+; 'RUNTSL' STORES THE ADDRESS OF THIS LINE AND EXECUTES IT.
+; 'RUNSML' CONTINUES THE EXECUTION ON SAME LINE.
+;
+; 'GOTO EXPR(CR)' EVALUATES THE EXPRESSION, FIND THE TARGET
+; LINE, AND JUMP TO 'RUNTSL' TO DO IT.
+;*************************************************************
+
+NEW:
+        CALL ENDCHK                     ;*** NEW(CR) ***
+        LD HL,TXTBGN
+        LD (TXTUNF),HL
+STOP:
+        CALL ENDCHK                     ;*** STOP(CR) ***
+        JP RSTART
+RUN:
+        CALL ENDCHK                     ;*** RUN(CR) ***
+        LD DE,TXTBGN                    ;FIRST SAVED LINE
+RUNNXL:
+        LD HL,00H                       ;*** RUNNXL ***
+        CALL FNDLP                      ;FIND WHATEVER LINE #
+        JP C,RSTART                     ;C:PASSED TXTUNF, QUIT
+RUNTSL:
+        EX DE,HL                        ;*** RUNTSL ***
+        LD (CURRNT),HL                  ;SET 'CURRENT'->LINE #
+        EX DE,HL
+        INC DE                          ;BUMP PASS LINE #
+        INC DE
+RUNSML:
+        CALL CHKIO                      ;*** RUNSML ***
+        LD HL,TAB2-1                    ;FIND COMMAND IN TAB2
+        JP EXEC                         ;AND EXECUTE IT
+GOTO:
+        RST 18H                         ;*** GOTO EXPR ***
+        PUSH DE                         ;SAVE FOR ERROR ROUTINE
+        CALL ENDCHK                     ;MUST FIND A CR
+        CALL FNDLN                      ;FIND THE TARGET LINE
+        JP NZ,AHOW                      ;NO SUCH LINE #
+        POP AF                          ;CLEAR THE PUSH DE
+        JR RUNTSL                       ;GO DO IT
+
+;*************************************************************
+;
+; *** LIST *** & PRINT ***
+;
+; LIST HAS TWO FORMS:
+; 'LIST(CR)' LISTS ALL SAVED LINES
+; 'LIST #(CR)' START LIST AT THIS LINE #
+; YOU CAN STOP THE LISTING BY CONTROL C KEY
+;
+; PRINT COMMAND IS 'PRINT ....;' OR 'PRINT ....(CR)'
+; WHERE '....' IS A LIST OF EXPRESIONS, FORMATS, BACK-
+; ARROWS, AND STRINGS.  THESE ITEMS ARE SEPERATED BY COMMAS.
+;
+; A FORMAT IS A POUND SIGN FOLLOWED BY A NUMBER.  IT CONTROLS
+; THE NUMBER OF SPACES THE VALUE OF A EXPRESION IS GOING TO
+; BE PRINTED.  IT STAYS EFFECTIVE FOR THE REST OF THE PRINT
+; COMMAND UNLESS CHANGED BY ANOTHER FORMAT.  IF NO FORMAT IS
+; SPECIFIED, 6 POSITIONS WILL BE USED.
+;
+; A STRING IS QUOTED IN A PAIR OF SINGLE QUOTES OR A PAIR OF
+; DOUBLE QUOTES.
+;
+; A BACK-ARROW MEANS GENERATE A (CR) WITHOUT (LF)
+;
+; A (CRLF) IS GENERATED AFTER THE ENTIRE LIST HAS BEEN
+; PRINTED OR IF THE LIST IS A NULL LIST.  HOWEVER IF THE LIST
+; ENDED WITH A COMMA, NO (CRLF) IS GENERATED.
+;*************************************************************
+
+LIST:
+        CALL TSTNUM                     ;TEST IF THERE IS A #
+        CALL ENDCHK                     ;IF NO # WE GET A 0
+        CALL FNDLN                      ;FIND THIS OR NEXT LINE
+LS1:
+        JP C,RSTART                     ;C:PASSED TXTUNF
+        CALL PRTLN                      ;PRINT THE LINE
+        CALL CHKIO                      ;STOP IF HIT CONTROL-C
+        CALL FNDLP                      ;FIND NEXT LINE
+        JR LS1                          ;AND LOOP BACK
+PRINT:
+        LD C,06H                        ;C = # OF SPACES
+        RST 08H                         ;F NULL LIST & ";"
+        DB 3BH
+        DB PR2-$-1
+        CALL CRLF                       ;GIVE CR-LF AND
+        JR RUNSML                       ;CONTINUE SAME LINE
+PR2:
+        RST 08H                         ;IF NULL LIST (CR)
+        DB CR
+        DB PR0-$-1
+        CALL CRLF                       ;ALSO GIVE CR-LF AND
+        JR RUNNXL                       ;GO TO NEXT LINE
+PR0:
+        RST 08H                         ;ELSE IS IT FORMAT?
+        DB '#'
+        DB PR1-$-1
+        RST 18H                         ;YES, EVALUATE EXPR.
+        LD C,L                          ;AND SAVE IT IN C
+        JR PR3                          ;LOOK FOR MORE TO PRINT
+PR1:
+        CALL QTSTG                      ;OR IS IT A STRING?
+        JR PR8                          ;IF NOT, MUST BE EXPR.
+PR3:
+        RST 08H                         ;IF ",", GO FIND NEXT
+        DB ','
+        DB PR6-$-1
+        CALL FIN                        ;IN THE LIST.
+        JR PR0                          ;LIST CONTINUES
+PR6:
+        CALL CRLF                       ;LIST ENDS
+        RST 30H
+PR8:
+        RST 18H                         ;EVALUATE THE EXPR
+        PUSH BC
+        CALL PRTNUM                     ;PRINT THE VALUE
+        POP BC
+        JR PR3                          ;MORE TO PRINT?
+
+;*************************************************************
+;
+; *** GOSUB *** & RETURN ***
+;
+; 'GOSUB EXPR;' OR 'GOSUB EXPR (CR)' IS LIKE THE 'GOTO'
+; COMMAND, EXCEPT THAT THE CURRENT TEXT POINTER, STACK POINTER
+; ETC. ARE SAVE SO THAT EXECUTION CAN BE CONTINUED AFTER THE
+; SUBROUTINE 'RETURN'.  IN ORDER THAT 'GOSUB' CAN BE NESTED
+; (AND EVEN RECURSIVE), THE SAVE AREA MUST BE STACKED.
+; THE STACK POINTER IS SAVED IN 'STKGOS', THE OLD 'STKGOS' IS
+; SAVED IN THE STACK.  IF WE ARE IN THE MAIN ROUTINE, 'STKGOS'
+; IS ZERO (THIS WAS DONE BY THE "MAIN" SECTION OF THE CODE),
+; BUT WE STILL SAVE IT AS A FLAG FOR NO FURTHER 'RETURN'S.
+;
+; 'RETURN(CR)' UNDOS EVERYTHING THAT 'GOSUB' DID, AND THUS
+; RETURN THE EXECUTION TO THE COMMAND AFTER THE MOST RECENT
+; 'GOSUB'.  IF 'STKGOS' IS ZERO, IT INDICATES THAT WE
+; NEVER HAD A 'GOSUB' AND IS THUS AN ERROR.
+;*************************************************************
+
+GOSUB:
+        CALL PUSHA                      ;SAVE THE CURRENT "FOR"
+        RST 18H                         ;PARAMETERS
+        PUSH DE                         ;AND TEXT POINTER
+        CALL FNDLN                      ;FIND THE TARGET LINE
+        JP NZ,AHOW                      ;NOT THERE. SAY "HOW?"
+        LD HL,(CURRNT)                  ;FOUND IT, SAVE OLD.
+        PUSH HL                         ;'CURRNT' OLD 'STKGOS'
+        LD HL,(STKGOS)
+        PUSH HL
+        LD HL,0000H                     ;AND LOAD NEW ONES
+        LD (LOPVAR),HL
+        ADD HL,SP
+        LD (STKGOS),HL
+        JP RUNTSL                       ;THEN RUN THAT LINE
+RETURN:
+        CALL ENDCHK                     ;THERE MUST BE A CR
+        LD HL,(STKGOS)                  ;OLD STACK POINTER
+        LD A,H                          ;0 MEANS NOT EXIST
+        OR L
+        JP Z,QWHAT                      ;SO, WE SAY: "WHAT?"
+        LD SP,HL                        ;ELSE, RESTORE IT
+        POP HL
+        LD (STKGOS),HL                  ;AND THE OLD "STKGOS"
+        POP HL
+        LD (CURRNT),HL                  ;AND THE OLD 'CURRNT'
+        POP DE                          ;OLD TEXT POINTER
+        CALL POPA                       ;OLD "FOR" PARAMETERS
+        RST 30H                         ;AND WE ARE BACK HOME
+
+;*************************************************************
+;
+; *** FOR *** & NEXT ***
+;
+; 'FOR' HAS TWO FORMS:
+; 'FOR VAR=EXP1 TO EXP2 STEP EXP3' AND 'FOR VAR=EXP1 TO EXP2'
+; THE SECOND FORM MEANS THE SAME THING AS THE FIRST FORM WITH
+; EXP3=1.  (I.E., WITH A STEP OF +1.)
+; TBI WILL FIND THE VARIABLE VAR, AND SET ITS VALUE TO THE
+; CURRENT VALUE OF EXP1.  IT ALSO EVALUATES EXP2 AND EXP3
+; AND SAVE ALL THESE TOGETHER WITH THE TEXT POINTER ETC. IN
+; THE 'FOR' SAVE AREA, WHICH CONSISTS OF 'LOPVAR', 'LOPINC',
+; 'LOPLMT', 'LOPLN', AND 'LOPPT'.  IF THERE IS ALREADY SOME-
+; THING IN THE SAVE AREA (THIS IS INDICATED BY A NON-ZERO
+; 'LOPVAR'), THEN THE OLD SAVE AREA IS SAVED IN THE STACK
+; BEFORE THE NEW ONE OVERWRITES IT.
+; TBI WILL THEN DIG IN THE STACK AND FIND OUT IF THIS SAME
+; VARIABLE WAS USED IN ANOTHER CURRENTLY ACTIVE 'FOR' LOOP.
+; IF THAT IS THE CASE, THEN THE OLD 'FOR' LOOP IS DEACTIVATED.
+; (PURGED FROM THE STACK..)
+;
+; 'NEXT VAR' SERVES AS THE LOGICAL (NOT NECESSARILLY PHYSICAL)
+; END OF THE 'FOR' LOOP.  THE CONTROL VARIABLE VAR. IS CHECKED
+; WITH THE 'LOPVAR'.  IF THEY ARE NOT THE SAME, TBI DIGS IN
+; THE STACK TO FIND THE RIGHT ONE AND PURGES ALL THOSE THAT
+; DID NOT MATCH.  EITHER WAY, TBI THEN ADDS THE 'STEP' TO
+; THAT VARIABLE AND CHECK THE RESULT WITH THE LIMIT.  IF IT
+; IS WITHIN THE LIMIT, CONTROL LOOPS BACK TO THE COMMAND
+; FOLLOWING THE 'FOR'.  IF OUTSIDE THE LIMIT, THE SAVE AREA
+; IS PURGED AND EXECUTION CONTINUES.
+;*************************************************************
+
+FOR:
+        CALL PUSHA                      ;SAVE THE OLD SAVE AREA
+        CALL SETVAL                     ;SET THE CONTROL VAR.
+        DEC HL                          ;HL IS ITS ADDRESS
+        LD (LOPVAR),HL                  ;SAVE THAT
+        LD HL,TAB5-1                    ;USE 'EXEC' TO LOOK
+        JP EXEC                         ;FOR THE WORK 'TO'
+FR1:
+        RST 18H                         ;EVALUATE THE LIMITE
+        LD (LOPLMT),HL                  ;SAVE THAT
+        LD HL,TAB6-1                    ;USE 'EXEC' TO LOOK
+        JP EXEC                         ;FOR THE WORD 'STEP'
+FR2:
+        RST 18H                         ;FOUND IT, GET STEP
+        JR FR4
+FR3:
+        LD HL,0001H                     ;NOT FOUND, SET TO 1
+FR4:
+        LD (LOPINC),HL                  ;SAVE THAT TOO
+FR5:
+        LD HL,(CURRNT)                  ;SAVE CURRENT LINE #
+        LD (LOPLN),HL
+        EX DE,HL                        ;AND TEXT POINTER
+        LD (LOPPT),HL
+        LD BC,0AH                       ;DIG INTO STACK TO
+        LD HL,(LOPVAR)                  ;FIND 'LOPVAR'
+        EX DE,HL
+        LD H,B
+        LD L,B                          ;HL=0 NOW
+        ADD HL,SP                       ;HERE IS THE STACK
+        DB 3EH                          ;DISASSEMBLY SAID "ld a,09h"
+FR7:
+        ADD HL,BC                       ;EACH LEVEL IS 10 DEEP - DIS = 09
+        LD A,(HL)                       ;GET THAT OLD 'LOPVAR'
+        INC HL
+        OR (HL)
+        JR Z,FR8                        ;0 SAYS NO MORE IN IT
+        LD A,(HL)
+        DEC HL
+        CP D                            ;SAME AS THIS ONE?
+        JR NZ,FR7
+        LD A,(HL)                       ;THE OTHER HALF?
+        CP E
+        JR NZ,FR7
+        EX DE,HL                        ;YES, FOUND ONE
+        LD HL,0000H
+        ADD HL,SP                       ;TRY TO MOVE SP
+        LD B,H
+        LD C,L
+        LD HL,000AH
+        ADD HL,DE
+        CALL MVDOWN                     ;AND PURGE 10 WORDS
+        LD SP,HL                        ;IN THE STACK
+FR8:
+        LD HL,(LOPPT)                   ;JOB DONE, RESTORE DE
+        EX DE,HL
+        RST 30H                         ;AND CONTINUE
+;
+NEXT:
+        RST 38H                         ;GET ADDRESS OF VAR.
+        JP C,QWHAT                      ;NO VARIABLE, "WHAT?"
+        LD (VARNXT),HL                  ;YES, SAVE IT
+NX0:
+        PUSH DE                         ;SAVE TEXT POINTER
+        EX DE,HL
+        LD HL,(LOPVAR)                  ;GET VAR. IN 'FOR'
+        LD A,H
+        OR L                            ;0 SAYS NEVER HAD ONE
+        JP Z,AWHAT                      ;SO WE ASK: "WHAT?"
+        RST 20H                         ;ELSE WE CHECK THEM
+        JR Z,NX3                        ;OK, THEY AGREE
+        POP DE                          ;NO, LET'S SEE
+        CALL POPA                       ;PURGE CURRENT LOOP
+        LD HL,(VARNXT)                  ;AND POP ONE LEVEL
+        JR NX0                          ;GO CHECK AGAIN
+NX3:
+        LD E,(HL)                       ;COME HERE WHEN AGREED
+        INC HL
+        LD D,(HL)                       ;DE=VALUE OF VAR.
+        LD HL,(LOPINC)
+        PUSH HL
+        LD A,H
+        XOR D
+        LD A,D
+        ADD HL,DE                       ;ADD ONE STEP
+        JP M,NX4
+        XOR H
+        JP M,NX5
+NX4:
+        EX DE,HL
+        LD HL,(LOPVAR)                  ;PUT IT BACK
+        LD (HL),E
+        INC HL
+        LD (HL),D
+        LD HL,(LOPLMT)                  ;HL->LIMIT
+        POP AF                          ;OLD HL
+        OR A
+        JP P,NX1                        ;STEP > 0
+        EX DE,HL                        ;STEP < 0
+NX1:
+        CALL CKHLDE                     ;COMPARE WITH LIMIT
+        POP DE                          ;RESTORE TEXT POINTER
+        JR C,NX2                        ;OUTSIDE LIMIT
+        LD HL,(LOPLN)                   ;WITHIN LIMIT, GO
+        LD (CURRNT),HL                  ;BACK TO THE SAVED
+        LD HL,(LOPPT)                   ;'CURRNT' AND TEXT
+        EX DE,HL                        ;POINTER
+        RST 30H
+NX5:
+        POP HL
+        POP DE
+NX2:
+        CALL POPA                       ;PURGE THIS LOOP
+        RST 30H
+
+;*************************************************************
+;
+; *** REM *** IF *** INPUT *** & LET (& DEFLT) ***
+;
+; 'REM' CAN BE FOLLOWED BY ANYTHING AND IS IGNORED BY TBI.
+; TBI TREATS IT LIKE AN 'IF' WITH A FALSE CONDITION.
+;
+; 'IF' IS FOLLOWED BY AN EXPR. AS A CONDITION AND ONE OR MORE
+; COMMANDS (INCLUDING OTHER 'IF'S) SEPERATED BY SEMI-COLONS.
+; NOTE THAT THE WORD 'THEN' IS NOT USED.  TBI EVALUATES THE
+; EXPR. IF IT IS NON-ZERO, EXECUTION CONTINUES.  IF THE
+; EXPR. IS ZERO, THE COMMANDS THAT FOLLOWS ARE IGNORED AND
+; EXECUTION CONTINUES AT THE NEXT LINE.
+;
+; 'INPUT' COMMAND IS LIKE THE 'PRINT' COMMAND, AND IS FOLLOWED
+; BY A LIST OF ITEMS.  IF THE ITEM IS A STRING IN SINGLE OR
+; DOUBLE QUOTES, OR IS A BACK-ARROW, IT HAS THE SAME EFFECT AS
+; IN 'PRINT'.  IF AN ITEM IS A VARIABLE, THIS VARIABLE NAME IS
+; PRINTED OUT FOLLOWED BY A COLON.  THEN TBI WAITS FOR AN
+; EXPR. TO BE TYPED IN.  THE VARIABLE IS THEN SET TO THE
+; VALUE OF THIS EXPR.  IF THE VARIABLE IS PROCEDED BY A STRING
+; (AGAIN IN SINGLE OR DOUBLE QUOTES), THE STRING WILL BE
+; PRINTED FOLLOWED BY A COLON.  TBI THEN WAITS FOR INPUT EXPR.
+; AND SET THE VARIABLE TO THE VALUE OF THE EXPR.
+;
+; IF THE INPUT EXPR. IS INVALID, TBI WILL PRINT "WHAT?",
+; "HOW?" OR "SORRY" AND REPRINT THE PROMPT AND REDO THE INPUT.
+; THE EXECUTION WILL NOT TERMINATE UNLESS YOU TYPE CONTROL-C.
+; THIS IS HANDLED IN 'INPERR'.
+;
+; 'LET' IS FOLLOWED BY A LIST OF ITEMS SEPERATED BY COMMAS.
+; EACH ITEM CONSISTS OF A VARIABLE, AN EQUAL SIGN, AND AN EXPR.
+; TBI EVALUATES THE EXPR. AND SET THE VARIABLE TO THAT VALUE.
+; TBI WILL ALSO HANDLE 'LET' COMMAND WITHOUT THE WORD 'LET'.
+; THIS IS DONE BY 'DEFLT'.
+;*************************************************************
+
+REM:
+        LD HL,0000H                     ;*** REM ***
+        DB 3EH                          ;THIS IS LIKE 'IF 0'
+IFF:
+        RST 18H                         ;*** IF ***
+        LD A,H                          ;IS THE EXPR.=0?
+        OR L
+        JP NZ,RUNSML                    ;NO, CONTINUE
+        CALL FNDSKP                     ;YES, SKIP REST OF LINE
+        JP NC,RUNTSL                    ;AND RUN THE NEXT LINE
+        JP RSTART                       ;IF NO NEXT, RE-START
+INPERR:
+        LD HL,(STKINP)                  ;*** INPERR ***
+        LD SP,HL                        ;RESTORE OLD SP
+        POP HL                          ;AND OLD 'CURRNT'
+        LD (CURRNT),HL
+        POP DE                          ;AND OLD TEXT POINTER
+        POP DE                          ;REDO INPUT
+INPUT:                                  ;*** INPUT ***
+IP1:
+        PUSH DE                         ;SAVE IN CASE OF ERROR
+        CALL QTSTG                      ;IS NEXT ITEM A STRING?
+        JR IP2                          ;NO
+        RST 38H                         ;YES, BUT FOLLOWED BY A
+        JR C,IP4                        ;VARIABLE? NO.
+        JR IP3                          ;YES. INPUT VARIABLE
+IP2:
+        PUSH DE                         ;SAVE FOR 'PRTSTG'
+        RST 38H                         ;MUST BE VARIABLE NOW
+        JP C,QWHAT                      ;"WHAT?" IT IS NOT?
+        LD A,(DE)                       ;GET READY FOR 'PRTSTR'
+        LD C,A
+        SUB A
+        LD (DE),A
+        POP DE
+        CALL PRTSTG                     ;PRINT STRING AS PROMPT
+        LD A,C                          ;RESTORE TEXT
+        DEC DE
+        LD (DE),A
+IP3:
+        PUSH DE                         ;SAVE TEXT POINTER
+        EX DE,HL
+        LD HL,(CURRNT)                  ;ALSO SAVE 'CURRNT'
+        PUSH HL
+        LD HL,IP1                       ;A NEGATIVE NUMBER
+        LD (CURRNT),HL                  ;AS A FLAG
+        LD HL,0000H                     ;SAVE SP TOO
+        ADD HL,SP
+        LD (STKINP),HL
+        PUSH DE                         ;OLD HL
+        LD A,3AH                        ;PRINT THIS TOO
+        CALL GETLN                      ;AND GET A LINE
+        LD DE,BUFFER                    ;POINTS TO BUFFER
+        RST 18H                         ;EVALUATE INPUT
+        NOP                             ;CAN BE 'CALL ENDCHK'
+        NOP
+        NOP
+        POP DE                          ;OK,GET OLD HL
+        EX DE,HL
+        LD (HL),E                       ;SAVE VALUE IN VAR.
+        INC HL
+        LD (HL),D
+        POP HL                          ;GET OLD 'CURRNT'
+        LD (CURRNT),HL
+        POP DE                          ;AND OLD TEXT POINTER
+IP4:
+        POP AF                          ;PURGE JUNK IN STACK
+        RST 08H                         ;IS NEXT CH. ','?
+        DB ','
+        DB IP5-$-1
+        JR IP1                          ;YES, MORE ITEMS.
+IP5:
+        RST 30H
+DEFLT:
+        LD A,(DE)                       ;***  DEFLT ***
+        CP CR                           ;EMPTY LINE IS OK
+        JR Z,LT1                        ;ELSE IT IS 'LET'
+LET:
+        CALL SETVAL                     ;*** LET ***
+        RST 08H                         ;SET VALUE TO VAR
+        DB ','                          ;---DISASSEMBLE = INC L
+        DB LT1-$-1                      ;---DISASSEMBLE = INC BC
+        JR LET                          ;ITEM BY ITEM
+LT1:
+        RST 30H                         ;UNTIL FINISH
+;*************************************************************
+;
+; *** EXPR ***
+;
+; 'EXPR' EVALUATES ARITHMETICAL OR LOGICAL EXPRESSIONS.
+; <EXPR>::<EXPR2>
+;         <EXPR2><REL.OP.><EXPR2>
+; WHERE <REL.OP.> IS ONE OF THE OPERATORS IN TAB8 AND THE
+; RESULT OF THESE OPERATIONS IS 1 IF TRUE AND 0 IF FALSE.
+; <EXPR2>::=(+ OR -)<EXPR3>(+ OR -<EXPR3>)(....)
+; WHERE () ARE OPTIONAL AND (....) ARE OPTIONAL REPEATS.
+; <EXPR3>::=<EXPR4>(* OR /><EXPR4>)(....)
+; <EXPR4>::=<VARIABLE>
+;           <FUNCTION>
+;           (<EXPR>)
+; <EXPR> IS RECURSIVE SO THAT VARIABLE '@' CAN HAVE AN <EXPR>
+; AS INDEX, FUNCTIONS CAN HAVE AN <EXPR> AS ARGUMENTS, AND
+; <EXPR4> CAN BE AN <EXPR> IN PARANTHESE.
+;*************************************************************
+
+EXPR1:
+        LD HL,TAB8-1                    ;LOOKUP REL.OP.
+        JP EXEC                         ;GO DO IT
+XP11:
+        CALL XP18                       ;REL.OP.">="
+        RET C                           ;NO, RETURN HL=0
+        LD L,A                          ;YES, RETURN HL=1
+        RET
+XP12:
+        CALL XP18                       ;REL.OP."#"
+        RET Z                           ;FALSE, RETURN HL=0
+        LD L,A                          ;TRUE, RETURN HL=1
+        RET
+XP13:
+        CALL XP18                       ;REL.OP.">"
+        RET Z                           ;FALSE
+        RET C                           ;ALSO FALSE, HL=0
+        LD L,A                          ;TRUE, HL=1
+        RET
+XP14:
+        CALL XP18                       ;REL.OP."<="
+        LD L,A                          ;SET HL=1
+        RET Z                           ;REL. TRUE, RETURN
+        RET C
+        LD L,H                          ;ELSE SET HL=0
+        RET
+XP15:
+        CALL XP18                       ;REL.OP."="
+        RET NZ                          ;FALSE, RETURN HL=0
+        LD L,A                          ;ELSE SET HL=1
+        RET
+XP16:
+        CALL XP18                       ;REL.OP."<"
+        RET NC                          ;FALSE, RETURN HL=0
+        LD L,A                          ;ELSE SET HL=1
+        RET
+XP17:
+        POP HL                          ;NOT .REL.OP
+        RET                             ;RETURN HL=<EXPR2>
+XP18:
+        LD A,C                          ;SUBROUTINE FOR ALL
+        POP HL                          ;REL.OP.'S
+        POP BC
+        PUSH HL                         ;REVERSE TOP OF STACK
+        PUSH BC
+        LD C,A
+        CALL EXPR2                      ;GET 2ND <EXPR2>
+        EX DE,HL                        ;VALUE IN DE NOW
+        EX (SP),HL                      ;1ST <EXPR2> IN HL
+        CALL CKHLDE                     ;COMPARE 1ST WITH 2ND
+        POP DE                          ;RESTORE TEXT POINTER
+        LD HL,0000H                     ;SET HL=0, A=1
+        LD A,01H
+        RET
+EXPR2:
+        RST 08H                         ;NEGATIVE SIGN?
+        DB '-'
+        DB XP21-$-1
+        LD HL,0000H                     ;YES, FAKE '0-'
+        JR XP26                         ;TREAT LIKE SUBTRACT
+XP21:
+        RST 08H                         ;POSITIVE SIGN? IGNORE
+        DB '+'
+        DB XP22-$-1
+XP22:
+        CALL EXPR3                      ;1ST <EXPR3>
+XP23:
+        RST 08H                         ;ADD?
+        DB  '+'
+        DB XP25-$-1
+        PUSH HL                         ;YES, SAVE VALUE
+        CALL EXPR3                      ;GET 2ND <EXPR3>
+XP24:
+        EX DE,HL                        ;2ND IN DE
+        EX (SP),HL                      ;1ST IN HL
+        LD A,H                          ;COMPARE SIGN
+        XOR D
+        LD A,D
+        ADD HL,DE
+        POP DE                          ;RESTORE TEXT POINTER
+        JP M,XP23                       ;1ST AND 2ND SIGN DIFFER
+        XOR H                           ;1ST AND 2ND SIGN EQUAL
+        JP P,XP23                       ;SO IS RESULT
+        JP QHOW                         ;ELSE WE HAVE OVERFLOW
+XP25:
+        RST 08H                         ;SUBTRACT?
+        DB '-'
+        DB XP42-$-1
+XP26:
+        PUSH HL                         ;YES, SAVE 1ST <EXPR3>
+        CALL EXPR3                      ;GET 2ND <EXPR3>
+        CALL CHGSGN                     ;NEGATE
+        JR XP24                         ;AND ADD THEM
+;
+EXPR3:
+        CALL EXPR4                      ;GET 1ST <EXPR4>
+XP31:
+        RST 08H                         ;MULTIPLY?
+        DB '*'
+        DB XP34-$-1
+        PUSH HL                         ;YES, SAVE 1ST
+        CALL EXPR4                      ;AND GET 2ND <EXPR4>
+        LD B,00H                        ;CLEAR B FOR SIGN
+        CALL CHKSGN                     ;CHECK SIGN
+        EX (SP),HL                      ;1ST IN HL
+        CALL CHKSGN                     ;CHECK SIGN OF 1ST
+        EX DE,HL
+        EX (SP),HL
+        LD A,H                          ;IS HL > 255 ?
+        OR A
+        JR Z,XP32                       ;NO
+        LD A,D                          ;YES, HOW ABOUT DE
+        OR D
+        EX DE,HL                        ;PUT SMALLER IN HL
+        JP NZ,AHOW                      ;ALSO >, WILL OVERFLOW
+XP32:
+        LD A,L                          ;THIS IS DUMB
+        LD HL,0000H                     ;CLEAR RESULT
+        OR A                            ;ADD AND COUNT
+        JR Z,XP35
+XP33:
+        ADD HL,DE
+        JP C,AHOW                       ;OVERFLOW
+        DEC A
+        JR NZ,XP33
+        JR XP35                         ;FINISHED
+XP34:
+        RST 08H                         ;DIVIDE?
+        DB '/'
+        DB XP42-$-1
+        PUSH HL                         ;YES, SAVE 1ST <EXPR4>
+        CALL EXPR4                      ;AND GET THE SECOND ONE
+        LD B,00H                        ;CLEAR B FOR SIGN
+        CALL CHKSGN                     ;CHECK SIGN OF 2ND
+        EX (SP),HL                      ;GET 1ST IN HL
+        CALL CHKSGN                     ;CHECK SIGN OF 1ST
+        EX DE,HL
+        EX (SP),HL
+        EX DE,HL
+        LD A,D                          ;DIVIDE BY 0?
+        OR E
+        JP Z,AHOW                       ;SAY "HOW?"
+        PUSH BC                         ;ELSE SAVE SIGN
+        CALL DIVIDE                     ;USE SUBROUTINE
+        LD H,B                          ;RESULT IN HL NOW
+        LD L,C
+        POP BC                          ;GET SIGN BACK
+XP35:
+        POP DE                          ;AND TEXT POINTER
+        LD A,H                          ;HL MUST BE +
+        OR A
+        JP M,QHOW                       ;ELSE IT IS OVERFLOW
+        LD A,B
+        OR A
+        CALL M,CHGSGN                   ;CHANGE SIGN IF NEEDED
+        JR XP31                         ;LOOK FOR MORE TERMS
+EXPR4:
+        LD HL,TAB4-1                    ;FIND FUNCTION IN TAB4
+        JP EXEC                         ;AND GO DO IT
+XP40:
+        RST 38H                         ;NO, NOT A FUNCTION
+        JR C,XP41                       ;NOR A VARIABLE
+        LD A,(HL)                       ;VARIABLE
+        INC HL
+        LD H,(HL)                       ;VALUE IN HL
+        LD L,A
+        RET
+XP41:
+        CALL TSTNUM                     ;OR IS IT A NUMBER
+        LD A,B                          ;# OF DIGIT
+        OR A
+        RET NZ                          ;OK
+PARN:
+        RST 08H
+        DB '('
+        DB XP43-$-1
+        RST 18H                         ;"(EXPR)"
+        RST 08H
+        DB ')'
+        DB XP43-$-1
+XP42:
+        RET
+XP43:
+        JP QWHAT                        ;ELSE SAY: "WHAT?"
+RND:
+        CALL PARN                       ;*** RND(EXPR) ***
+        LD A,H                          ;EXPR MUST BE +
+        OR A
+        JP M,QHOW
+        OR L                            ;AND NON-ZERO
+        JP Z,QHOW
+        PUSH DE                         ;SAVE BOTH
+        PUSH HL
+        LD HL,(RANPNT)                  ;GET MEMORY AS RANDOM
+        LD DE,LSTROM                    ;NUMBER
+        RST 20H
+        JR C,RA1                        ;WRAP AROUND IF LAST
+        LD HL,START
+RA1:
+        LD E,(HL)
+        INC HL
+        LD D,(HL)
+        LD (RANPNT),HL
+        POP HL
+        EX DE,HL
+        PUSH BC
+        CALL DIVIDE                     ;RND (N)=MOD(M,N)+1
+        POP BC
+        POP DE
+        INC HL
+        RET
+ABS:
+        CALL PARN                       ;*** ABS (EXPR) ***
+        DEC DE
+        CALL CHKSGN                     ;CHECK SIGN
+        INC DE
+        RET
+SIZE:
+        LD HL,(TXTUNF)                  ;*** SIZE ***
+        PUSH DE                         ;GET THE NUMBER OF FREE
+        EX DE,HL                        ;BYTES BETWEEN 'TXTUNF'
+        LD HL,VARBGN                    ;AND 'VARBGN'
+        CALL SUBDE
+        POP DE
+        RET
+;*************************************************************
+;
+; *** DIVIDE *** SUBDE *** CHKSGN *** CHGSGN *** & CKHLDE ***
+;
+; 'DIVIDE' DIVIDES HL BY DE, RESULT IN BC, REMAINDER IN HL
+;
+; 'SUBDE' SUBSTRACTS DE FROM HL
+;
+; 'CHKSGN' CHECKS SIGN OF HL.  IF +, NO CHANGE.  IF -, CHANGE
+; SIGN AND FLIP SIGN OF B.
+;
+; 'CHGSGN' CHECKS SIGN N OF HL AND B UNCONDITIONALLY.
+;
+; 'CKHLDE' CHECKS SIGN OF HL AND DE.  IF DIFFERENT, HL AND DE
+; ARE INTERCHANGED.  IF SAME SIGN, NOT INTERCHANGED.  EITHER
+; CASE, HL DE ARE THEN COMPARED TO SET THE FLAGS.
+;*************************************************************
+
+DIVIDE:
+        PUSH HL                         ;*** DIVIDE ***
+        LD L,H                          ;DIVIDE H BY DE
+        LD H,00H
+        CALL DV1
+        LD B,C                          ;SAVE RESULT IN B
+        LD A,L                          ;(REMAINDER+L)/DE
+        POP HL
+        LD H,A
+DV1:
+        LD C,0FFH                       ;RESULT IN C
+DV2:
+        INC C                           ;DUMB ROUTINE
+        CALL SUBDE                      ;DIVIDE BY SUBTRACT
+        JR NC,DV2                       ;AND COUNT
+        ADD HL,DE
+        RET
+SUBDE:
+        LD A,L                          ;*** SUBDE ***
+        SUB E                           ;SUBSTRACT DE FROM
+        LD L,A                          ;HL
+        LD A,H
+        SBC A,D
+        LD H,A
+        RET
+CHKSGN:
+        LD A,H                          ;*** CHKSGN ***
+        OR A                            ;CHECK SIGN OF HL
+        RET P
+CHGSGN:
+        LD A,H                          ;*** CHGSGN ***
+        PUSH AF
+        CPL                             ;CHANGE SIGN OF HL
+        LD H,A
+        LD A,L
+        CPL
+        LD L,A
+        INC HL
+        POP AF
+        XOR H
+        JP P,QHOW
+        LD A,B                          ;AND ALSO FLIP B
+        XOR 80H
+        LD B,A
+        RET
+CKHLDE:
+        LD A,H                          ;SAME SIGN?
+        XOR D                           ;YES, COMPARE
+        JP P,CK1                        ;NO, XCHANGE AND COMP
+        EX DE,HL
+CK1:
+        RST 20H
+        RET
+;*************************************************************
+;
+; *** SETVAL *** FIN *** ENDCHK *** & ERROR (& FRIENDS) ***
+;
+; "SETVAL" EXPECTS A VARIABLE, FOLLOWED BY AN EQUAL SIGN AND
+; THEN AN EXPR.  IT EVALUATES THE EXPR. AND SET THE VARIABLE
+; TO THAT VALUE.
+;
+; "FIN" CHECKS THE END OF A COMMAND.  IF IT ENDED WITH ";",
+; EXECUTION CONTINUES.  IF IT ENDED WITH A CR, IT FINDS THE
+; NEXT LINE AND CONTINUE FROM THERE.
+;
+; "ENDCHK" CHECKS IF A COMMAND IS ENDED WITH CR.  THIS IS
+; REQUIRED IN CERTAIN COMMANDS.  (GOTO, RETURN, AND STOP ETC.)
+;
+; "ERROR" PRINTS THE STRING POINTED BY DE (AND ENDS WITH CR).
+; IT THEN PRINTS THE LINE POINTED BY 'CURRNT' WITH A "?"
+; INSERTED AT WHERE THE OLD TEXT POINTER (SHOULD BE ON TOP
+; OF THE STACK) POINTS TO.  EXECUTION OF TB IS STOPPED
+; AND TBI IS RESTARTED.  HOWEVER, IF 'CURRNT' -> ZERO
+; (INDICATING A DIRECT COMMAND), THE DIRECT COMMAND IS NOT
+; PRINTED.  AND IF 'CURRNT' -> NEGATIVE # (INDICATING 'INPUT'
+; COMMAND), THE INPUT LINE IS NOT PRINTED AND EXECUTION IS
+; NOT TERMINATED BUT CONTINUED AT 'INPERR'.
+;
+; RELATED TO 'ERROR' ARE THE FOLLOWING:
+; 'QWHAT' SAVES TEXT POINTER IN STACK AND GET MESSAGE "WHAT?"
+; 'AWHAT' JUST GET MESSAGE "WHAT?" AND JUMP TO 'ERROR'.
+; 'QSORRY' AND 'ASORRY' DO SAME KIND OF THING.
+; 'AHOW' AND 'AHOW' IN THE ZERO PAGE SECTION ALSO DO THIS.
+;*************************************************************
+
+SETVAL:
+        RST 38H                         ;*** SETVAL ***
+        JP C,QWHAT                      ;"WHAT?" NO VARIABLE
+        PUSH HL                         ;SAVE ADDRESS OF VAR.
+        RST 08H                         ;PASS "=" SIGN
+        DB '='
+        DB SV1-$-1
+        RST 18H                         ;EVALUATE EXPR.
+        LD B,H                          ;VALUE IS IN BC NOW
+        LD C,L
+        POP HL                          ;GET ADDRESS
+        LD (HL),C                       ;SAVE VALUE
+        INC HL
+        LD (HL),B
+        RET
+SV1:
+        JP QWHAT                        ;NO "=" SIGN
+FIN:
+        RST 08H                         ;*** FIN ***
+        DB 3BH
+        DB FI1-$-1
+        POP AF                          ;";", PURGE RET. ADDR.
+        JP RUNSML                       ;CONTINUE SAME LINE
+FI1:
+        RST 08H                         ;NOT ";", IS IT CR?
+        DB CR
+        DB FI2-$-1
+        POP AF                          ;YES, PURGE RET. ADDR.
+        JP RUNNXL                       ;RUN NEXT LINE
+FI2:
+        RET                             ;ELSE RETURN TO CALLER
+ENDCHK:
+        RST 28H                         ;*** ENDCHK ***
+        CP CR                           ;END WITH CR?
+        RET Z                           ;OK, ELSE SAY: "WHAT?"
+QWHAT:
+        PUSH DE                         ;*** QWHAT ***
+AWHAT:
+        LD DE,WHAT                      ;*** AWHAT ***
+ERROR_ROUTINE:
+        SUB A                           ;*** ERROR ***
+        CALL PRTSTG                     ;PRINT 'WHAT?', 'HOW?'
+        POP DE                          ;OR 'SORRY'
+        LD A,(DE)                       ;SAVE THE CHARACTER
+        PUSH AF                         ;AT WHERE OLD DE ->
+        SUB A                           ;AND PUT A 0 THERE
+        LD (DE),A
+        LD HL,(CURRNT)                  ;GET CURRENT LINE #
+        PUSH HL
+        LD A,(HL)                       ;CHECK THE VALUE
+        INC HL
+        OR (HL)
+        POP DE
+        JP Z,RSTART                     ;IF ZERO, JUST RESTART
+        LD A,(HL)                       ;IF NEGATIVE,
+        OR A
+        JP M,INPERR                     ;REDO INPUT
+        CALL PRTLN                      ;ELSE PRINT THE LINE
+        DEC DE                          ;UPTO WHERE THE 0 IS
+        POP AF                          ;RESTORE THE CHARACTER
+        LD (DE),A
+        LD A,3FH                        ;PRINT A "?"
+        RST 10H
+        SUB A                           ;AND THE REST OF THE
+        CALL PRTSTG                     ;LINE
+        JP RSTART                       ;THEN RESTART
+QSORRY:
+        PUSH DE                         ;*** QSORRY ***
+ASORRY:
+        LD DE,SORRY                     ;*** ASORRY ***
+        JR ERROR_ROUTINE
+;*************************************************************
+;
+; *** GETLN *** FNDLN (& FRIENDS) ***
+;
+; 'GETLN' READS A INPUT LINE INTO 'BUFFER'.  IT FIRST PROMPT
+; THE CHARACTER IN A (GIVEN BY THE CALLER), THEN IT FILLS
+; THE BUFFER AND ECHOS.  IT IGNORES LF'S AND NULLS, BUT STILL
+; ECHOS THEM BACK.  RUB-OUT IS USED TO CAUSE IT TO DELETE
+; THE LAST CHARACTER (IF THERE IS ONE), AND ALT-MOD IS USED TO
+; CAUSE IT TO DELETE THE WHOLE LINE AND START IT ALL OVER.
+; CR SIGNALS THE END OF A LINE, AND CAUSE 'GETLN' TO RETURN.
+;
+; 'FNDLN' FINDS A LINE WITH A GIVEN LINE # (IN HL) IN THE
+; TEXT SAVE AREA.  DE IS USED AS THE TEXT POINTER.  IF THE
+; LINE IS FOUND, DE WILL POINT TO THE BEGINNING OF THAT LINE
+; (I.E., THE LOW BYTE OF THE LINE #), AND FLAGS ARE NC & Z.
+; IF THAT LINE IS NOT THERE AND A LINE WITH A HIGHER LINE #
+; IS FOUND, DE POINTS TO THERE AND FLAGS ARE NC & NZ.  IF
+; WE REACHED THE END OF TEXT SAVE AREA AND CANNOT FIND THE
+; LINE, FLAGS ARE C & NZ.
+; 'FNDLN' WILL INITIALIZE DE TO THE BEGINNING OF THE TEXT SAVE
+; AREA TO START THE SEARCH.  SOME OTHER ENTRIES OF THIS
+; ROUTINE WILL NOT INITIALIZE DE AND DO THE SEARCH.
+; 'FNDLNP' WILL START WITH DE AND SEARCH FOR THE LINE #.
+; 'FNDNXT' WILL BUMP DE BY 2, FIND A CR AND THEN START SEARCH.
+; 'FNDSKP' USE DE TO FIND A CR, AND THEN START SEARCH.
+;*************************************************************
+
+GETLN:
+        RST 10H                         ;*** GETLN ***
+        LD DE,BUFFER                    ;PROMPT AND INIT.
+GL1:
+        CALL CHKIO                      ;CHECK KEYBOARD
+        JR Z,GL1                        ;NO INPUT, WAIT
+        CP 7FH                          ;DELETE LAST CHARACTER?
+        JR Z,GL3                        ;YES
+        RST 10H                         ;INPUT, ECHO BACK
+        CP 0AH                          ;IGNORE LF
+        JR Z,GL1
+        OR A                            ;IGNORE NULL
+        JR Z,GL1
+        CP 7DH                          ;DELETE THE WHOLE LINE?
+        JR Z,GL4                        ;YES
+        LD (DE),A                       ;ELSE SAVE INPUT
+        INC DE                          ;AND BUMP POINTER
+        CP 0DH                          ;WAS IT CR
+        RET Z                           ;YES, END OF LINE
+        LD A,E                          ;ELSE MORE FREE ROOM?
+        CP BUFEND & 0FFH
+        JR NZ,GL1                       ;YES, GET NEXT INPUT
+GL3:
+        LD A,E                          ;DELETE LAST CHARACTER
+        CP BUFFER & 0FFH                ;BUT DO WE HAVE ANY?
+        JR Z,GL4                        ;NO, REDO WHOLE LINE
+        DEC DE                          ;YES, BACKUP POINTER
+        LD A,5CH                        ;AND ECHO A BACK-SLASH
+        RST 10H
+        JR GL1                          ;GO GET NEXT INPUT
+GL4:
+        CALL CRLF                       ;REDO ENTIRE LINE
+        LD A,05EH                       ;CR, LF AND UP-ARROW
+        JR GETLN
+FNDLN:
+        LD A,H                          ;*** FNDLN ***
+        OR A                            ;CHECK SIGN OF HL
+        JP M,QHOW                       ;IT CANNOT BE -
+        LD DE,TXTBGN                    ;INIT TEXT POINTER
+FNDLP:                                  ;*** FDLNP ***
+FL1:
+        PUSH HL                         ;SAVE LINE #
+        LD HL,(TXTUNF)                  ;CHECK IF WE PASSED END
+        DEC HL
+        RST 20H
+        POP HL                          ;GET LINE # BACK
+        RET C                           ;C,NZ PASSED END
+        LD A,(DE)                       ;WE DID NOT, GET BYTE 1
+        SUB L                           ;IS THIS THE LINE?
+        LD B,A                          ;COMPARE LOW ORDER
+        INC DE
+        LD A,(DE)                       ;GET BYTE 2
+        SBC A,H                         ;COMPARE HIGH ORDER
+        JR C,FL2                        ;NO, NOT THERE YET
+        DEC DE                          ;ELSE WE EITHER FOUND
+        OR B                            ;IT, OR IT IS NOT THERE
+        RET                             ;NC,Z;FOUND, NC,NZ:NO
+FNDNXT:                                 ;*** FNDNXT ***
+        INC DE                          ;FIND NEXT LINE
+FL2:
+        INC DE                          ;JUST PASSED BYTE 1 & 2
+FNDSKP:
+        LD A,(DE)                       ;*** FNDSKP ***
+        CP CR                           ;TRY TO FIND CR
+        JR NZ,FL2                       ;KEEP LOOKING
+        INC DE                          ;FOUND CR, SKIP OVER
+        JR FL1                          ;CHECK IF END OF TEXT
+;*************************************************************
+;
+; *** PRTSTG *** QTSTG *** PRTNUM *** & PRTLN ***
+;
+; 'PRTSTG' PRINTS A STRING POINTED BY DE.  IT STOPS PRINTING
+; AND RETURNS TO CALLER WHEN EITHER A CR IS PRINTED OR WHEN
+; THE NEXT BYTE IS THE SAME AS WHAT WAS IN A (GIVEN BY THE
+; CALLER).  OLD A IS STORED IN B, OLD B IS LOST.
+;
+; 'QTSTG' LOOKS FOR A BACK-ARROW, SINGLE QUOTE, OR DOUBLE
+; QUOTE.  IF NONE OF THESE, RETURN TO CALLER.  IF BACK-ARROW,
+; OUTPUT A CR WITHOUT A LF.  IF SINGLE OR DOUBLE QUOTE, PRINT
+; THE STRING IN THE QUOTE AND DEMANDS A MATCHING UNQUOTE.
+; AFTER THE PRINTING THE NEXT 3 BYTES OF THE CALLER IS SKIPPED
+; OVER (USUALLY A JUMP INSTRUCTION.
+;
+; 'PRTNUM' PRINTS THE NUMBER IN HL.  LEADING BLANKS ARE ADDED
+; IF NEEDED TO PAD THE NUMBER OF SPACES TO THE NUMBER IN C.
+; HOWEVER, IF THE NUMBER OF DIGITS IS LARGER THAN THE # IN
+; C, ALL DIGITS ARE PRINTED ANYWAY.  NEGATIVE SIGN IS ALSO
+; PRINTED AND COUNTED IN, POSITIVE SIGN IS NOT.
+;
+; 'PRTLN' PRINTS A SAVED TEXT LINE WITH LINE # AND ALL.
+;*************************************************************
+
+PRTSTG:
+        LD B,A                          ;*** PRTSTG ***
+PS1:
+        LD A,(DE)                       ;GET A CHARACTER
+        INC DE                          ;BUMP POINTER
+        CP B                            ;SAME AS OLD A?
+        RET Z                           ;YES, RETURN
+        RST 10H                         ;NO, NEXT
+        CP CR                           ;WAS IT A CR?
+        JR NZ,PS1                       ;NO, NEXT
+        RET                             ;YES, RETURN
+QTSTG:
+        RST 08H                         ;*** QTSTG ***
+        DB '"'
+        DB QT3-$-1
+        LD A,22H                        ;IT IS A "
+QT1:
+        CALL PRTSTG                     ;PRINT UNTIL ANOTHER
+        CP CR                           ;WAS LAST ONE A CR?
+        POP HL                          ;RETURN ADDRESS
+        JP Z,RUNNXL                     ;WAS CR, RUN NEXT LINE
+QT2:
+        INC HL                          ;SKIP 3 BYTES ON RETURN
+        INC HL
+        INC HL
+        JP (HL)                         ;RETURN
+QT3:
+        RST 08H                         ;IS IT A '?
+        DB 27H
+        DB QT4-$-1
+        LD A,27H                        ;YES, DO THE SAME
+        JR QT1                          ;AS IN "
+QT4:
+        RST 08H                         ;IS IT BACK-ARROW?
+        DB 5FH
+        DB QT5-$-1
+        LD A,8DH                        ;YES, CR WITHOUT LF
+        RST 10H                         ;DO IT TWICE TO GIVE
+        RST 10H                         ;TTY ENOUGH TIME
+        POP HL                          ;RETURN ADDRESS
+        JR QT2
+QT5:
+        RET                             ;NONE OF ABOVE
+;
+PRTNUM:
+        LD B,00H                        ;*** PRTNUM ***
+        CALL CHKSGN                     ;CHECK SIGN
+        JP P,PN1                        ;NO SIGN
+        LD B,'-'                        ;B=SIGN
+        DEC C                           ;'-' TAKES SPACE
+PN1:
+        PUSH DE                         ;SAVE
+        LD DE,000AH                     ;DECIMAL
+        PUSH DE                         ;SAVE AS FLAG
+        DEC C                           ;C=SPACES
+        PUSH BC                         ;SAVE SIGN & SPACE
+PN2:
+        CALL DIVIDE                     ;DIVIDE HL BY 10
+        LD A,B                          ;RESULT 0?
+        OR C
+        JR Z,PN3                        ;YES, WE GOT ALL
+        EX (SP),HL                      ;NO, SAVE REMAINDER
+        DEC L                           ;AND COUNT SPACE
+        PUSH HL                         ;HL IS OLD BC
+        LD H,B                          ;MOVE RESULT TO BC
+        LD L,C
+        JR PN2                          ;AND DIVIDE BY 10
+PN3:
+        POP BC                          ;WE GOT ALL DIGITS IN
+PN4:
+        DEC C                           ;THE STACK
+        LD A,C                          ;LOOK AT SPACE COUNT
+        OR A
+        JP M,PN5                        ;NO LEADING BLANKS
+        LD A,20H                        ;LEADING BLANKS
+        RST 10H
+        JR PN4                          ;MORE?
+PN5:
+        LD A,B                          ;PRINT SIGN
+        OR A
+        CALL NZ,0010H
+        LD E,L                          ;LAST REMAINDER IN E
+PN6:
+        LD A,E                          ;CHECK DIGIT IN E
+        CP 0AH                          ;10 IS FLAG FOR NO MORE
+        POP DE
+        RET Z                           ;IF SO, RETURN
+        ADD A,30H                       ;ELSE, CONVERT TO ASCII
+        RST 10H                         ;PRINT THE DIGIT
+        JR PN6                          ;GO BACK FOR MORE
+PRTLN:
+        LD A,(DE)                       ;*** PRTLN ***
+        LD L,A                          ;LOW ORDER LINE #
+        INC DE
+        LD A,(DE)                       ;HIGH ORDER
+        LD H,A
+        INC DE
+        LD C,04H                        ;PRINT 4 DIGIT LINE #
+        CALL PRTNUM
+        LD A,20H                        ;FOLLOWED BY A BLANK
+        RST 10H
+        SUB A                           ;AND THEN THE NEXT
+        CALL PRTSTG
+        RET
+;*************************************************************
+;
+; *** MVUP *** MVDOWN *** POPA *** & PUSHA ***
+;
+; 'MVUP' MOVES A BLOCK UP FROM WHERE DE-> TO WHERE BC-> UNTIL
+; DE = HL
+;
+; 'MVDOWN' MOVES A BLOCK DOWN FROM WHERE DE-> TO WHERE HL->
+; UNTIL DE = BC
+;
+; 'POPA' RESTORES THE 'FOR' LOOP VARIABLE SAVE AREA FROM THE
+; STACK
+;
+; 'PUSHA' STACKS THE 'FOR' LOOP VARIABLE SAVE AREA INTO THE
+; STACK
+;*************************************************************
+
+MVUP:
+        RST 20H                         ;*** MVUP ***
+        RET Z                           ;DE = HL, RETURN
+        LD A,(DE)                       ;GET ONE BYTE
+        LD (BC),A                       ;MOVE IT
+        INC DE                          ;INCREASE BOTH POINTERS
+        INC BC
+        JR MVUP                         ;UNTIL DONE
+MVDOWN:
+        LD A,B                          ;*** MVDOWN ***
+        SUB D                           ;TEST IF DE = BC
+        JP NZ,MD1                       ;NO, GO MOVE
+        LD A,C                          ;MAYBE, OTHER BYTE?
+        SUB E
+        RET Z                           ;YES, RETURN
+MD1:
+        DEC DE                          ;ELSE MOVE A BYTE
+        DEC HL                          ;BUT FIRST DECREASE
+        LD A,(DE)                       ;BOTH POINTERS AND
+        LD (HL),A                       ;THEN DO IT
+        JR MVDOWN                       ;LOOP BACK
+POPA:
+        POP BC                          ;BC = RETURN ADDR.
+        POP HL                          ;RESTORE LOPVAR, BUT
+        LD (LOPVAR),HL                  ;=0 MEANS NO MORE
+        LD A,H
+        OR L
+        JR Z,PP1                        ;YEP, GO RETURN
+        POP HL                          ;NOP, RESTORE OTHERS
+        LD (LOPINC),HL
+        POP HL
+        LD (LOPLMT),HL
+        POP HL
+        LD (LOPLN),HL
+        POP HL
+        LD (LOPPT),HL
+PP1:
+        PUSH BC                         ;BC = RETURN ADDR.
+        RET
+PUSHA:
+        LD HL,STKLMT                    ;*** PUSHA ***
+        CALL CHGSGN
+        POP BC                          ;BC=RETURN ADDRESS
+        ADD HL,SP                       ;IS STACK NEAR THE TOP?
+        JP NC,QSORRY                    ;YES, SORRY FOR THAT
+        LD HL,(LOPVAR)                  ;ELSE SAVE LOOP VAR'S
+        LD A,H                          ;BUT IF LOPVAR IS 0
+        OR L                            ;THAT WILL BE ALL
+        JR Z,PU1
+        LD HL,(LOPPT)                   ;ELSE, MORE TO SAVE
+        PUSH HL
+        LD HL,(LOPLN)
+        PUSH HL
+        LD HL,(LOPLMT)
+        PUSH HL
+        LD HL,(LOPINC)
+        PUSH HL
+        LD HL,(LOPVAR)
+PU1:
+        PUSH HL
+        PUSH BC                         ;BC = RETURN ADDR.
+        RET
+;*************************************************************
+;
+; *** OUTC *** & CHKIO ***
+;
+; THESE ARE THE ONLY I/O ROUTINES IN TBI.
+; 'OUTC' IS CONTROLLED BY A SOFTWARE SWITCH 'OCSW'.  IF OCSW=0
+; 'OUTC' WILL JUST RETURN TO THE CALLER.  IF OCSW IS NOT 0,
+; IT WILL OUTPUT THE BYTE IN A.  IF THAT IS A CR, A LF IS ALSO
+; SEND OUT.  ONLY THE FLAGS MAY BE CHANGED AT RETURN. ALL REG.
+; ARE RESTORED.
+;
+; 'CHKIO' CHECKS THE INPUT.  IF NO INPUT, IT WILL RETURN TO
+; THE CALLER WITH THE Z FLAG SET.  IF THERE IS INPUT, Z FLAG
+; IS CLEARED AND THE INPUT BYTE IS IN A.  HOWEVER, IF THE
+; INPUT IS A CONTROL-O, THE 'OCSW' SWITCH IS COMPLIMENTED, AND
+; Z FLAG IS RETURNED.  IF A CONTROL-C IS READ, 'CHKIO' WILL
+; RESTART TBI AND DO NOT RETURN TO THE CALLER.
+;
+; Do not modify these routines.  Routines requiring
+; modification are : SERIAL_INIT, RX_RDY, and TX_RDY.
+;*************************************************************
+
+INIT:
+        CALL SERIAL_INIT        ;INITIALIZE THE SIO
+        LD D,19H
+PATLOP:
+        CALL CRLF
+        DEC D
+        JR NZ,PATLOP
+        SUB A
+        LD DE,MSG1          ;PRINT THE BOOT MESSAGES
+        CALL PRTSTG
+        LD DE,MSG2
+        CALL PRTSTG
+        LD HL,START
+        LD (RANPNT),HL
+        LD HL,TXTBGN
+        LD (TXTUNF),HL
+        JP RSTART
+OUTC:
+        JR NZ,OUTC2         ;IT IS ON
+        POP AF                          ;IT IS OFF
+        RET                             ;RESTORE AF AND RETURN
+OUTC2:
+        CALL TX_RDY         ;SEE IF TRANSMIT IS AVAILABLE
+        POP AF                          ;RESTORE THE REGISTER
+        OUT (SerialPort),A      ;SEND THE BYTE
+        CP CR
+        RET NZ
+        LD A,LF
+        RST 10H
+        LD A,CR
+        RET
+CHKIO:
+        CALL RX_RDY         ;CHECK IF CHARACTER AVAILABLE
+        RET Z                           ;RETURN IF NO CHARACTER AVAILABLE
+
+        PUSH BC                         ;IF IT'S A LF, IGNORE AND RETURN
+        LD B,A                          ; AS IF THERE WAS NO CHARACTER.
+        SUB LF
+        JR Z,CHKIO2
+        LD A,B                          ;OTHERWISE RESTORE 'A' AND 'BC'
+        POP BC                          ; AND CONTINUE ON.
+
+        CP 0FH                          ;IS IT CONTROL-0?
+        JR NZ,CI1                       ;NO, MORE CHECKING
+        LD A,(OCSW)                     ;CONTROL-0 FLIPS OCSW
+        CPL                             ;ON TO OFF, OFF TO ON
+        LD (OCSW),A
+        JR CHKIO                        ;GET ANOTHER INPUT
+CHKIO2:
+        LD A,00H                        ;CLEAR A
+        OR A                            ;ZET THE Z-FLAG
+        POP BC                          ;RESTORE THE 'BC' PAIR
+        RET                             ;RETURN WITH 'Z' SET.
+CI1:
+        CP 03H                          ;IS IT CONTROL-C?
+        RET NZ                          ;NO, RETURN "NZ"
+        JP RSTART                       ;YES, RESTART TBI
+
+
+MSG1:   DB   ESC,"[2J",ESC,"[H"         ;SCREEN CLEAR
+        DB   'Z80 TINY BASIC 2.0g',CR       ;BOOT MESSAGE
+MSG2:   DB   'PORTED BY DOUG GABBARD, 2017',CR
+
+;*************************************************************
+;
+; *** TABLES *** DIRECT *** & EXEC ***
+;
+; THIS SECTION OF THE CODE TESTS A STRING AGAINST A TABLE.
+; WHEN A MATCH IS FOUND, CONTROL IS TRANSFERED TO THE SECTION
+; OF CODE ACCORDING TO THE TABLE.
+;
+; AT 'EXEC', DE SHOULD POINT TO THE STRING AND HL SHOULD POINT
+; TO THE TABLE-1.  AT 'DIRECT', DE SHOULD POINT TO THE STRING.
+; HL WILL BE SET UP TO POINT TO TAB1-1, WHICH IS THE TABLE OF
+; ALL DIRECT AND STATEMENT COMMANDS.
+;
+; A '.' IN THE STRING WILL TERMINATE THE TEST AND THE PARTIAL
+; MATCH WILL BE CONSIDERED AS A MATCH.  E.G., 'P.', 'PR.',
+; 'PRI.', 'PRIN.', OR 'PRINT' WILL ALL MATCH 'PRINT'.
+;
+; THE TABLE CONSISTS OF ANY NUMBER OF ITEMS.  EACH ITEM
+; IS A STRING OF CHARACTERS WITH BIT 7 SET TO 0 AND
+; A JUMP ADDRESS STORED HI-LOW WITH BIT 7 OF THE HIGH
+; BYTE SET TO 1.
+;
+; END OF TABLE IS AN ITEM WITH A JUMP ADDRESS ONLY.  IF THE
+; STRING DOES NOT MATCH ANY OF THE OTHER ITEMS, IT WILL
+; MATCH THIS NULL ITEM AS DEFAULT.
+;*************************************************************
+
+TAB1:                                   ;DIRECT COMMANDS
+        DB 'LIST'
+        DWA LIST
+        DB 'RUN'
+        DWA RUN
+        DB 'NEW'
+        DWA NEW
+TAB2:                                   ;DIRECT/STATEMENT
+        DB 'NEXT'
+        DWA NEXT
+        DB 'LET'
+        DWA LET
+        DB 'IF'
+        DWA IFF
+        DB 'GOTO'
+        DWA GOTO
+        DB 'GOSUB'
+        DWA GOSUB
+        DB 'RETURN'
+        DWA RETURN
+        DB 'REM'
+        DWA REM
+        DB 'FOR'
+        DWA FOR
+        DB 'INPUT'
+        DWA INPUT
+        DB 'PRINT'
+        DWA PRINT
+        DB 'STOP'
+        DWA STOP
+        DWA DEFLT
+TAB4:                                   ;FUNCTIONS
+        DB 'RND'
+        DWA RND
+        DB 'ABS'
+        DWA ABS
+        DB 'SIZE'
+        DWA SIZE
+        DWA XP40
+TAB5:                                   ;"TO" IN "FOR"
+        DB 'TO'
+        DWA FR1
+        DWA QWHAT
+TAB6:                                   ;"STEP" IN "FOR"
+        DB 'STEP'
+        DWA FR2
+        DWA FR3
+TAB8:                                   ;RELATION OPERATORS
+        DB '>='
+        DWA XP11
+        DB '#'
+        DWA XP12
+        DB '>'
+        DWA XP13
+        DB '='
+        DWA XP15
+        DB '<='
+        DWA XP14
+        DB '<'
+        DWA XP16
+        DWA XP17
+DIRECT: LD HL,TAB1-1                   ;*** DIRECT ***
+EXEC:                                   ;*** EXEC ***
+EX0:    RST 28H                         ;IGNORE LEADING BLANKS
+        PUSH DE                         ;SAVE POINTER
+EX1:
+        LD A,(DE)                       ;IF FOUND '.' IN STRING
+        INC DE                          ;BEFORE ANY MISMATCH
+        CP 23H                          ;WE DECLARE A MATCH
+        JR Z,EX3
+        INC HL                          ;HL->TABLE
+        CP (HL)                         ;IF MATCH, TEST NEXT
+        JR Z,EX1
+        LD A,7FH                        ;ELSE SEE IF BIT 7
+        DEC DE                          ;OF TABLE IS SET, WHICH
+        CP (HL)                         ;IS THE JUMP ADDR. (HI)
+        JR C,EX5                        ;C:YES, MATCHED
+EX2:
+        INC HL                          ;NC:NO, FIND JUMP ADDR.
+        CP (HL)
+        JR NC,EX2
+        INC HL                          ;BUMP TO NEXT TAB. ITEM
+        POP DE                          ;RESTORE STRING POINTER
+        JR EX0                          ;TEST AGAINST NEXT ITEM
+EX3:
+        LD A,7FH                        ;PARTIAL MATCH, FIND
+EX4:
+        INC HL                          ;JUMP ADDR., WHICH IS
+        CP (HL)                         ;FLAGGED BY BIT 7
+        JR NC,EX4
+EX5:
+        LD A,(HL)                       ;LOAD HL WITH THE JUMP
+        INC HL                          ;ADDRESS FROM THE TABLE
+        LD L,(HL)
+        AND 7FH                         ;MASK OFF BIT 7
+        LD H,A
+        POP AF                          ;CLEAN UP THE GABAGE
+        JP (HL)                         ;AND WE GO DO IT
+;-------------------------------------------------------------------------------
+;///////////////////////////////////////////////////////////////////////////////
+;-------------------------------------------------------------------------------
+;COMPUTER SPECIFIC ROUTINES.
+;-------------------------------------------------------------------------------
+SERIAL_INIT:
+
+    ; This routine is for initializing your serial port.
+
+        RET
+;-------------------------------------------------------------------------------
+TX_RDY:
+
+    ; This routine is checking if the Serial Port is ready to send
+    ; a character.
+    
+    RET
+        
+;-------------------------------------------------------------------------------
+RX_RDY:
+
+    ; This routine is for checkif if a character is available over
+    ; serial. If a character is available, it returns to the calling
+    ; function with the character in 'A' and the Z-flag reset.
+    ; However, if a character is not available, it returns with the
+    ; Z-flag set.
+
+        RET
+;-------------------------------------------------------------------------------
+;///////////////////////////////////////////////////////////////////////////////
+;-------------------------------------------------------------------------------
+
+LSTROM:                                 ;ALL ABOVE CAN BE ROM
+                    ;HERE DOWN MUST BE RAM
+        ORG  08000H
+        ORG  0FF00H
+VARBGN: DS   55                         ;VARIABLE @(0)
+BUFFER: DS   64                         ;INPUT BUFFER
+BUFEND: DS   1                          ;BUFFER ENDS
+STKLMT: DS   1                          ;TOP LIMIT FOR STACK
+        END

snapshots/jotego_jtcores_pr1100/modules/jtframe/asm/z80/jtTinyBasic.asm

@@ -0,0 +1,1789 @@
+;*************************************************************
+;
+;                 TINY BASIC FOR ZILOG Z80
+;                       VERSION 2.0
+;                     BY LI-CHEN WANG
+;
+;                  MODIFIED AND TRANSLATED
+;                    TO INTEL MNEMONICS
+;                     BY ROGER RAUSKOLB
+;                      10 OCTOBER,1976
+;
+;                  MODIFIED AND TRANSLATED
+;                    TO ZILOG MNEMONICS
+;                      BY DOUG GABBARD
+;            www.retrodepot.net
+;
+;           RELEASED TO THE PUBLIC
+;                      10 OCTOBER,2017
+;                  YEAH, 41 YEARS LATER....
+;
+;                         @COPYLEFT
+;                   ALL WRONGS RESERVED
+;
+;*************************************************************
+; This code is derived from the original 8080 Tiny Basic.
+; It was first compiled in 8080 Mnemonics, then disassembled
+; into Zilog Mnemonics.  And then checked against the original
+; to ensure accuracy.  It was then partially enhanced with z80
+; specific code. And once done, it was then modified to work
+; with the G80-S Micro Computer. However, that portion of the
+; code has been left out in order to make this code a little
+; more portable.  There are only three routines that one needs
+; to write, and specifing the serial port's I/O address, in
+; order to make this version work with your own DIY computer.
+; Those routines can be found at the end of the source code.
+;
+; I hope you find good use for this relic. However, I would
+; ask that if you do find use for it, please put a reference
+; to me in your work. And please, distribute freely.
+;*************************************************************
+; Notes for JTFrame version:
+;  Adapted to work with GNU z80asm
+;  Added interrupt handling
+
+SerialPort:     EQU     0F0H            ; This the serial output port
+
+
+SPACE:          EQU     020H            ; Space
+TAB:            EQU     09H             ; HORIZONTAL TAB
+CTRLC:          EQU     03H             ; Control "C"
+CTRLG:          EQU     07H             ; Control "G"
+BKSP:           EQU     08H             ; Back space
+LF:             EQU     0AH             ; Line feed
+CS:             EQU     0CH             ; Clear screen
+CR:             EQU     0DH             ; Carriage return
+CTRLO:          EQU     0FH             ; Control "O"
+CTRLQ:          EQU     011H            ; Control "Q"
+CTRLR:          EQU     012H            ; Control "R"
+CTRLS:          EQU     013H            ; Control "S"
+CTRLU:          EQU     015H            ; Control "U"
+ESC:            EQU     01BH            ; Escape
+DEL:            EQU     07FH            ; Delete
+
+; Adjust to fit RAM mapping
+STACK:          EQU     087FFH          ; STACK (Last RAM address)
+OCSW:           EQU     08000H          ;SWITCH FOR OUTPUT
+CURRNT:         EQU     OCSW+1          ;POINTS FOR OUTPUT
+STKGOS:         EQU     OCSW+3          ;SAVES SP IN 'GOSUB'
+VARNXT:         EQU     OCSW+5          ;TEMP STORAGE
+STKINP:         EQU     OCSW+7          ;SAVES SP IN 'INPUT'
+LOPVAR:         EQU     OCSW+9          ;'FOR' LOOP SAVE AREA
+LOPINC:         EQU     OCSW+11         ;INCREMENT
+LOPLMT:         EQU     OCSW+13         ;LIMIT
+LOPLN:          EQU     OCSW+15         ;LINE NUMBER
+LOPPT:          EQU     OCSW+17         ;TEXT POINTER
+RANPNT:         EQU     OCSW+19         ;RANDOM NUMBER POINTER
+TXTUNF:         EQU     OCSW+21         ;->UNFILLED TEXT AREA
+TXTBGN:         EQU     OCSW+23         ;TEXT SAVE AREA BEGINS
+
+TXTEND:         EQU     08700H          ;TEXT SAVE AREA ENDS
+
+
+;*************************************************************
+; *** ZERO PAGE SUBROUTINES ***
+;
+; THE Z80 INSTRUCTION SET ALLOWS FOR 8 ROUTINES IN LOW MEMORY
+; THAT MAY BE CALLED BY RST 00H, 08H, 10H, 18H, 20H, 28H, 30H,
+; AND 38H.  THIS IS A ONE BYTE INSTRUCTION, AND IS FUNCTIONALLY
+; SIMILAR TO THE THREE BYTE INSTRUCTION 'CALL XXXX'. TINY BASIC
+; WILL USE THE RST INSTRUCTION FOR THE 7 MOST FREQUENTLY USED
+; SUBROUTINES. TWO OTHER SUBROUTINES (CRLF & TSTNUM) ARE ALSO
+; IN THIS SECTION. THEY CAN BE REACHED WITH 'CALL'.
+;*************************************************************
+
+DWA:    MACRO WHERE
+        DB   (WHERE >> 8) + 128
+        DB   WHERE & 0FFH
+        ENDM
+
+        ORG  0000H
+
+START:
+        LD SP,STACK                     ;*** COLD START ***
+        LD A,0FFH
+        JP INIT
+
+RST08:  EX (SP),HL                      ;*** TSTC OR RST 08H ***
+        RST 28H                         ;IGNORE BLANKS AND
+        CP (HL)                         ;TEST CHARACTER
+        JP TC1                          ;REST OF THIS IS AT TC1
+
+CRLF:
+        LD A,CR                         ;*** CRLF ***
+
+RST10:  PUSH AF                         ;*** OUTC OR RST 10H ***
+        LD A,(OCSW)                     ;PRINT CHARACTER ONLY
+        OR A                            ;IF OCSW SWITCH IS ON
+        JP OUTC                         ;REST OF THIS AT OUTC
+
+RST18:  CALL EXPR2                      ;*** EXPR OR RST 18H ***
+        PUSH HL                         ;EVALUATE AN EXPRESSION
+        JP EXPR1                        ;REST OF IT AT EXPR1
+        DB 'W'
+
+RST20:  LD A,H                          ;*** COMP OR RST 20H ***
+        CP D                            ;COMPARE HL WITH DE
+        RET NZ                          ;RETURN CORRECT C AND
+        LD A,L                          ;Z FLAGS
+        CP E                            ;BUT OLD A IS LOST
+        RET
+        DB 'AN'
+
+SS1:
+RST28:  LD A,(DE)                       ;*** IGNBLK/RST 28H ***
+        CP 20H                          ;IGNORE BLANKS
+        RET NZ                          ;IN TEXT (WHERE DE->)
+        INC DE                          ;AND RETURN THE FIRST
+        JP SS1                          ;NON-BLANK CHAR. IN A
+
+RST30:  POP AF                          ;*** FINISH/RST 30H ***
+        CALL FIN                        ;CHECK END OF COMMAND
+        JP QWHAT                        ;PRINT "WHAT?" IF WRONG
+        DB 'G'
+
+RST38:  RST 28H                         ;*** TSTV OR RST 38H ***
+        SUB 40H                         ;TEST VARIABLES
+        RET C                           ;C:NOT A VARIABLE
+        JR NZ,TV1                       ;NOT "@" ARRAY
+        INC DE                          ;IT IS THE "@" ARRAY
+        CALL PARN                       ;@ SHOULD BE FOLLOWED
+        ADD HL,HL                       ;BY (EXPR) AS ITS INDEX
+        JR C,QHOW                       ;IS INDEX TOO BIG?
+        PUSH DE                         ;WILL IT OVERWRITE
+        EX DE,HL                        ;TEXT?
+        CALL SIZE                       ;FIND SIZE OF FREE
+        RST 20H                         ;AND CHECK THAT
+        JP C,ASORRY                     ;IF SO, SAY "SORRY"
+        LD HL,VARBGN                    ;IF NOT GET ADDRESS
+        CALL SUBDE                      ;OF @(EXPR) AND PUT IT
+        POP DE                          ;IN HL
+        RET                             ;C FLAG IS CLEARED
+
+TV1:
+        CP 1BH                          ;NOT @, IS IT A TO Z?
+        CCF                             ;IF NOT RETURN C FLAG
+        RET C
+        INC DE                          ;IF A THROUGH Z
+        LD HL,VARBGN                    ;COMPUTE ADDRESS OF
+        RLCA                            ;THAT VARIABLE
+        ADD A,L                         ;AND RETURN IT IN HL
+        LD L,A                          ;WITH C FLAG CLEARED
+        LD A,00H
+        ADC A,H
+        LD H,A
+        RET
+
+NMI66:                                  ;MUST BE AT 66H
+        RETI
+
+TC1:
+        INC HL                          ;COMPARE THE BYTE THAT
+        JR Z,TC2                        ;FOLLOWS THE RST INST.
+        PUSH BC                         ;WITH THE TEXT (DE->)
+        LD C,(HL)                       ;IF NOT =, ADD THE 2ND
+        LD B,00H                        ;BYTE THAT FOLLOWS THE
+        ADD HL,BC                       ;RST TO THE OLD PC
+        POP BC                          ;I.E., DO A RELATIVE
+        DEC DE                          ;JUMP IF NOT =
+
+TC2:
+        INC DE                          ;IF =, SKIP THOSE BYTES
+        INC HL                          ;AND CONTINUE
+        EX (SP),HL
+        RET
+
+TSTNUM:
+        LD HL,0000H                     ;*** TSTNUM ***
+        LD B,H                          ;TEST IF THE TEXT IS
+        RST 28H                         ;A NUMBER
+
+TN1:
+        CP 30H                          ;IF NOT, RETURN 0 IN
+        RET C                           ;B AND HL
+        CP 3AH                          ;IF NUMBERS, CONVERT
+        RET NC                          ;TO BINARY IN HL AND
+        LD A,0F0H                       ;SET B TO # OF DIGITS
+        AND H                           ;IF H>255, THERE IS NO
+        JR NZ,QHOW                      ;ROOM FOR NEXT DIGIT
+        INC B                           ;B COUNTS # OF DIGITS
+        PUSH BC
+        LD B,H                          ;HL=10*HL+(NEW DIGIT)
+        LD C,L
+        ADD HL,HL                       ;WHERE 10* IS DONE BY
+        ADD HL,HL                       ;SHIFT AND ADD
+        ADD HL,BC
+        ADD HL,HL
+        LD A,(DE)                       ;AND (DIGIT) IS FROM
+        INC DE                          ;STRIPPING THE ASCII
+        AND 0FH                         ;CODE
+        ADD A,L
+        LD L,A
+        LD A,00H
+        ADC A,H
+        LD H,A
+        POP BC
+        LD A,(DE)                       ;DO THIS DIGIT AFTER
+        JP P,TN1                        ;DIGIT. S SAYS OVERFLOW
+
+QHOW:
+        PUSH DE                         ;*** ERROR "HOW?" ***
+AHOW:
+        LD DE,HOW
+        JP ERROR_ROUTINE
+
+
+HOW:    DB "HOW?",CR
+OK:     DB "OK",CR
+WHAT:   DB "WHAT?",CR
+SORRY:  DB "SORRY",CR
+
+;*************************************************************
+;
+; *** MAIN ***
+;
+; THIS IS THE MAIN LOOP THAT COLLECTS THE TINY BASIC PROGRAM
+; AND STORES IT IN THE MEMORY.
+;
+; AT START, IT PRINTS OUT "(CR)OK(CR)", AND INITIALIZES THE
+; STACK AND SOME OTHER INTERNAL VARIABLES.  THEN IT PROMPTS
+; ">" AND READS A LINE.  IF THE LINE STARTS WITH A NON-ZERO
+; NUMBER, THIS NUMBER IS THE LINE NUMBER.  THE LINE NUMBER
+; (IN 16 BIT BINARY) AND THE REST OF THE LINE (INCLUDING CR)
+; IS STORED IN THE MEMORY.  IF A LINE WITH THE SAME LINE
+; NUMBER IS ALREADY THERE, IT IS REPLACED BY THE NEW ONE.  IF
+; THE REST OF THE LINE CONSISTS OF A CR ONLY, IT IS NOT STORED
+; AND ANY EXISTING LINE WITH THE SAME LINE NUMBER IS DELETED.
+;
+; AFTER A LINE IS INSERTED, REPLACED, OR DELETED, THE PROGRAM
+; LOOPS BACK AND ASKS FOR ANOTHER LINE.  THIS LOOP WILL BE
+; TERMINATED WHEN IT READS A LINE WITH ZERO OR NO LINE
+; NUMBER; AND CONTROL IS TRANSFERED TO "DIRECT".
+;
+; TINY BASIC PROGRAM SAVE AREA STARTS AT THE MEMORY LOCATION
+; LABELED "TXTBGN" AND ENDS AT "TXTEND".  WE ALWAYS FILL THIS
+; AREA STARTING AT "TXTBGN", THE UNFILLED PORTION IS POINTED
+; BY THE CONTENT OF A MEMORY LOCATION LABELED "TXTUNF".
+;
+; THE MEMORY LOCATION "CURRNT" POINTS TO THE LINE NUMBER
+; THAT IS CURRENTLY BEING INTERPRETED.  WHILE WE ARE IN
+; THIS LOOP OR WHILE WE ARE INTERPRETING A DIRECT COMMAND
+; (SEE NEXT SECTION). "CURRNT" SHOULD POINT TO A 0.
+;*************************************************************
+
+RSTART:
+        LD SP,STACK
+
+ST1:
+        CALL CRLF                       ;AND JUMP TO HERE
+        LD DE,OK                        ;DE->STRING
+        SUB A                           ;A=0
+        CALL PRTSTG                     ;PRINT STRING UNTIL CR
+        LD HL,ST2+1                     ;LITERAL 0
+        LD (CURRNT),HL                  ;CURRENT->LINE # = 0
+
+ST2:
+        LD HL,0000H
+        LD (LOPVAR),HL
+        LD (STKGOS),HL
+
+ST3:
+        LD A,'>'                        ;PROMPT '>' AND
+        CALL GETLN                      ;READ A LINE
+        PUSH DE                         ;DE->END OF LINE
+        LD DE,BUFFER                    ;DE->BEGINNING OF LINE
+        CALL TSTNUM                     ;TEST IF IT IS A NUMBER
+        RST 28H
+        LD A,H                          ;HL=VALUE OF THE # OR
+        OR L                            ;0 IF NO # WAS FOUND
+        POP BC                          ;BC->END OF LINE
+        JP Z,DIRECT
+        DEC DE                          ;BACKUP DE AND SAVE
+        LD A,H                          ;VALUE OF LINE # THERE
+        LD (DE),A
+        DEC DE
+        LD A,L
+        LD (DE),A
+        PUSH BC                         ;BC,DE->BEGIN, END
+        PUSH DE
+        LD A,C
+        SUB E
+
+        PUSH AF                         ;A=# OF BYTES IN LINE
+        CALL FNDLN                      ;FIND THIS LINE IN SAVE
+        PUSH DE                         ;AREA, DE->SAVE AREA
+        JR NZ,ST4                       ;NZ:NOT FOUND, INSERT
+        PUSH DE                         ;Z:FOUND, DELETE IT
+        CALL FNDNXT                     ;FIND NEXT LINE
+                                        ;DE->NEXT LINE
+        POP BC                          ;BC->LINE TO BE DELETED
+        LD HL,(TXTUNF)                  ;HL->UNFILLED SAVE AREA
+        CALL MVUP                       ;MOVE UP TO DELETE
+        LD H,B                          ;TXTUNF->UNFILLED ARA
+        LD L,C
+        LD (TXTUNF),HL                  ;UPDATE
+
+ST4:
+        POP BC                          ;GET READY TO INSERT
+        LD HL,(TXTUNF)                  ;BUT FIRST CHECK IF
+        POP AF                          ;THE LENGTH OF NEW LINE
+        PUSH HL                         ;IS 3 (LINE # AND CR)
+        CP 03H                          ;THEN DO NOT INSERT
+        JR Z,RSTART                     ;MUST CLEAR THE STACK
+        ADD A,L                         ;COMPUTE NEW TXTUNF
+        LD L,A
+        LD A,00H
+        ADC A,H
+        LD H,A                          ;HL->NEW UNFILLED AREA
+        LD DE,TXTEND                    ;CHECK TO SEE IF THERE
+        RST 20H                         ;IS ENOUGH SPACE
+        JP NC,QSORRY                    ;SORRY, NO ROOM FOR IT
+        LD (TXTUNF),HL                  ;OK, UPDATE TXTUNF
+        POP DE                          ;DE->OLD UNFILLED AREA
+        CALL MVDOWN
+        POP DE                          ;DE->BEGIN, HL->END
+        POP HL
+        CALL MVUP                       ;MOVE NEW LINE TO SAVE
+        JR ST3                          ;AREA
+
+;*************************************************************
+;
+; WHAT FOLLOWS IS THE CODE TO EXECUTE DIRECT AND STATEMENT
+; COMMANDS.  CONTROL IS TRANSFERED TO THESE POINTS VIA THE
+; COMMAND TABLE LOOKUP CODE OF 'DIRECT' AND 'EXEC' IN LAST
+; SECTION.  AFTER THE COMMAND IS EXECUTED, CONTROL IS
+; TRANSFERED TO OTHERS SECTIONS AS FOLLOWS:
+;
+; FOR 'LIST', 'NEW', AND 'STOP': GO BACK TO 'RSTART'
+; FOR 'RUN': GO EXECUTE THE FIRST STORED LINE IF ANY, ELSE
+; GO BACK TO 'RSTART'.
+; FOR 'GOTO' AND 'GOSUB': GO EXECUTE THE TARGET LINE.
+; FOR 'RETURN' AND 'NEXT': GO BACK TO SAVED RETURN LINE.
+; FOR ALL OTHERS: IF 'CURRENT' -> 0, GO TO 'RSTART', ELSE
+; GO EXECUTE NEXT COMMAND.  (THIS IS DONE IN 'FINISH'.)
+;*************************************************************
+;
+; *** NEW *** STOP *** RUN (& FRIENDS) *** & GOTO ***
+;
+; 'NEW(CR)' SETS 'TXTUNF' TO POINT TO 'TXTBGN'
+;
+; 'STOP(CR)' GOES BACK TO 'RSTART'
+;
+; 'RUN(CR)' FINDS THE FIRST STORED LINE, STORE ITS ADDRESS (IN
+; 'CURRENT'), AND START EXECUTE IT.  NOTE THAT ONLY THOSE
+; COMMANDS IN TAB2 ARE LEGAL FOR STORED PROGRAM.
+;
+; THERE ARE 3 MORE ENTRIES IN 'RUN':
+; 'RUNNXL' FINDS NEXT LINE, STORES ITS ADDR. AND EXECUTES IT.
+; 'RUNTSL' STORES THE ADDRESS OF THIS LINE AND EXECUTES IT.
+; 'RUNSML' CONTINUES THE EXECUTION ON SAME LINE.
+;
+; 'GOTO EXPR(CR)' EVALUATES THE EXPRESSION, FIND THE TARGET
+; LINE, AND JUMP TO 'RUNTSL' TO DO IT.
+;*************************************************************
+
+NEW:
+        CALL ENDCHK                     ;*** NEW(CR) ***
+        LD HL,TXTBGN
+        LD (TXTUNF),HL
+STOP:
+        CALL ENDCHK                     ;*** STOP(CR) ***
+        JP RSTART
+RUN:
+        CALL ENDCHK                     ;*** RUN(CR) ***
+        LD DE,TXTBGN                    ;FIRST SAVED LINE
+RUNNXL:
+        LD HL,00H                       ;*** RUNNXL ***
+        CALL FNDLP                      ;FIND WHATEVER LINE #
+        JP C,RSTART                     ;C:PASSED TXTUNF, QUIT
+RUNTSL:
+        EX DE,HL                        ;*** RUNTSL ***
+        LD (CURRNT),HL                  ;SET 'CURRENT'->LINE #
+        EX DE,HL
+        INC DE                          ;BUMP PASS LINE #
+        INC DE
+RUNSML:
+        CALL CHKIO                      ;*** RUNSML ***
+        LD HL,TAB2-1                    ;FIND COMMAND IN TAB2
+        JP EXEC                         ;AND EXECUTE IT
+GOTO:
+        RST 18H                         ;*** GOTO EXPR ***
+        PUSH DE                         ;SAVE FOR ERROR ROUTINE
+        CALL ENDCHK                     ;MUST FIND A CR
+        CALL FNDLN                      ;FIND THE TARGET LINE
+        JP NZ,AHOW                      ;NO SUCH LINE #
+        POP AF                          ;CLEAR THE PUSH DE
+        JR RUNTSL                       ;GO DO IT
+
+;*************************************************************
+;
+; *** LIST *** & PRINT ***
+;
+; LIST HAS TWO FORMS:
+; 'LIST(CR)' LISTS ALL SAVED LINES
+; 'LIST #(CR)' START LIST AT THIS LINE #
+; YOU CAN STOP THE LISTING BY CONTROL C KEY
+;
+; PRINT COMMAND IS 'PRINT ....;' OR 'PRINT ....(CR)'
+; WHERE '....' IS A LIST OF EXPRESIONS, FORMATS, BACK-
+; ARROWS, AND STRINGS.  THESE ITEMS ARE SEPERATED BY COMMAS.
+;
+; A FORMAT IS A POUND SIGN FOLLOWED BY A NUMBER.  IT CONTROLS
+; THE NUMBER OF SPACES THE VALUE OF A EXPRESION IS GOING TO
+; BE PRINTED.  IT STAYS EFFECTIVE FOR THE REST OF THE PRINT
+; COMMAND UNLESS CHANGED BY ANOTHER FORMAT.  IF NO FORMAT IS
+; SPECIFIED, 6 POSITIONS WILL BE USED.
+;
+; A STRING IS QUOTED IN A PAIR OF SINGLE QUOTES OR A PAIR OF
+; DOUBLE QUOTES.
+;
+; A BACK-ARROW MEANS GENERATE A (CR) WITHOUT (LF)
+;
+; A (CRLF) IS GENERATED AFTER THE ENTIRE LIST HAS BEEN
+; PRINTED OR IF THE LIST IS A NULL LIST.  HOWEVER IF THE LIST
+; ENDED WITH A COMMA, NO (CRLF) IS GENERATED.
+;*************************************************************
+
+LIST:
+        CALL TSTNUM                     ;TEST IF THERE IS A #
+        CALL ENDCHK                     ;IF NO # WE GET A 0
+        CALL FNDLN                      ;FIND THIS OR NEXT LINE
+LS1:
+        JP C,RSTART                     ;C:PASSED TXTUNF
+        CALL PRTLN                      ;PRINT THE LINE
+        CALL CHKIO                      ;STOP IF HIT CONTROL-C
+        CALL FNDLP                      ;FIND NEXT LINE
+        JR LS1                          ;AND LOOP BACK
+PRINT:
+        LD C,06H                        ;C = # OF SPACES
+        RST 08H                         ;F NULL LIST & ";"
+        DB 3BH
+        DB PR2-$-1
+        CALL CRLF                       ;GIVE CR-LF AND
+        JR RUNSML                       ;CONTINUE SAME LINE
+PR2:
+        RST 08H                         ;IF NULL LIST (CR)
+        DB CR
+        DB PR0-$-1
+        CALL CRLF                       ;ALSO GIVE CR-LF AND
+        JR RUNNXL                       ;GO TO NEXT LINE
+PR0:
+        RST 08H                         ;ELSE IS IT FORMAT?
+        DB '#'
+        DB PR1-$-1
+        RST 18H                         ;YES, EVALUATE EXPR.
+        LD C,L                          ;AND SAVE IT IN C
+        JR PR3                          ;LOOK FOR MORE TO PRINT
+PR1:
+        CALL QTSTG                      ;OR IS IT A STRING?
+        JR PR8                          ;IF NOT, MUST BE EXPR.
+PR3:
+        RST 08H                         ;IF ",", GO FIND NEXT
+        DB ','
+        DB PR6-$-1
+        CALL FIN                        ;IN THE LIST.
+        JR PR0                          ;LIST CONTINUES
+PR6:
+        CALL CRLF                       ;LIST ENDS
+        RST 30H
+PR8:
+        RST 18H                         ;EVALUATE THE EXPR
+        PUSH BC
+        CALL PRTNUM                     ;PRINT THE VALUE
+        POP BC
+        JR PR3                          ;MORE TO PRINT?
+
+;*************************************************************
+;
+; *** GOSUB *** & RETURN ***
+;
+; 'GOSUB EXPR;' OR 'GOSUB EXPR (CR)' IS LIKE THE 'GOTO'
+; COMMAND, EXCEPT THAT THE CURRENT TEXT POINTER, STACK POINTER
+; ETC. ARE SAVE SO THAT EXECUTION CAN BE CONTINUED AFTER THE
+; SUBROUTINE 'RETURN'.  IN ORDER THAT 'GOSUB' CAN BE NESTED
+; (AND EVEN RECURSIVE), THE SAVE AREA MUST BE STACKED.
+; THE STACK POINTER IS SAVED IN 'STKGOS', THE OLD 'STKGOS' IS
+; SAVED IN THE STACK.  IF WE ARE IN THE MAIN ROUTINE, 'STKGOS'
+; IS ZERO (THIS WAS DONE BY THE "MAIN" SECTION OF THE CODE),
+; BUT WE STILL SAVE IT AS A FLAG FOR NO FURTHER 'RETURN'S.
+;
+; 'RETURN(CR)' UNDOS EVERYTHING THAT 'GOSUB' DID, AND THUS
+; RETURN THE EXECUTION TO THE COMMAND AFTER THE MOST RECENT
+; 'GOSUB'.  IF 'STKGOS' IS ZERO, IT INDICATES THAT WE
+; NEVER HAD A 'GOSUB' AND IS THUS AN ERROR.
+;*************************************************************
+
+GOSUB:
+        CALL PUSHA                      ;SAVE THE CURRENT "FOR"
+        RST 18H                         ;PARAMETERS
+        PUSH DE                         ;AND TEXT POINTER
+        CALL FNDLN                      ;FIND THE TARGET LINE
+        JP NZ,AHOW                      ;NOT THERE. SAY "HOW?"
+        LD HL,(CURRNT)                  ;FOUND IT, SAVE OLD.
+        PUSH HL                         ;'CURRNT' OLD 'STKGOS'
+        LD HL,(STKGOS)
+        PUSH HL
+        LD HL,0000H                     ;AND LOAD NEW ONES
+        LD (LOPVAR),HL
+        ADD HL,SP
+        LD (STKGOS),HL
+        JP RUNTSL                       ;THEN RUN THAT LINE
+RETURN:
+        CALL ENDCHK                     ;THERE MUST BE A CR
+        LD HL,(STKGOS)                  ;OLD STACK POINTER
+        LD A,H                          ;0 MEANS NOT EXIST
+        OR L
+        JP Z,QWHAT                      ;SO, WE SAY: "WHAT?"
+        LD SP,HL                        ;ELSE, RESTORE IT
+        POP HL
+        LD (STKGOS),HL                  ;AND THE OLD "STKGOS"
+        POP HL
+        LD (CURRNT),HL                  ;AND THE OLD 'CURRNT'
+        POP DE                          ;OLD TEXT POINTER
+        CALL POPA                       ;OLD "FOR" PARAMETERS
+        RST 30H                         ;AND WE ARE BACK HOME
+
+;*************************************************************
+;
+; *** FOR *** & NEXT ***
+;
+; 'FOR' HAS TWO FORMS:
+; 'FOR VAR=EXP1 TO EXP2 STEP EXP3' AND 'FOR VAR=EXP1 TO EXP2'
+; THE SECOND FORM MEANS THE SAME THING AS THE FIRST FORM WITH
+; EXP3=1.  (I.E., WITH A STEP OF +1.)
+; TBI WILL FIND THE VARIABLE VAR, AND SET ITS VALUE TO THE
+; CURRENT VALUE OF EXP1.  IT ALSO EVALUATES EXP2 AND EXP3
+; AND SAVE ALL THESE TOGETHER WITH THE TEXT POINTER ETC. IN
+; THE 'FOR' SAVE AREA, WHICH CONSISTS OF 'LOPVAR', 'LOPINC',
+; 'LOPLMT', 'LOPLN', AND 'LOPPT'.  IF THERE IS ALREADY SOME-
+; THING IN THE SAVE AREA (THIS IS INDICATED BY A NON-ZERO
+; 'LOPVAR'), THEN THE OLD SAVE AREA IS SAVED IN THE STACK
+; BEFORE THE NEW ONE OVERWRITES IT.
+; TBI WILL THEN DIG IN THE STACK AND FIND OUT IF THIS SAME
+; VARIABLE WAS USED IN ANOTHER CURRENTLY ACTIVE 'FOR' LOOP.
+; IF THAT IS THE CASE, THEN THE OLD 'FOR' LOOP IS DEACTIVATED.
+; (PURGED FROM THE STACK..)
+;
+; 'NEXT VAR' SERVES AS THE LOGICAL (NOT NECESSARILLY PHYSICAL)
+; END OF THE 'FOR' LOOP.  THE CONTROL VARIABLE VAR. IS CHECKED
+; WITH THE 'LOPVAR'.  IF THEY ARE NOT THE SAME, TBI DIGS IN
+; THE STACK TO FIND THE RIGHT ONE AND PURGES ALL THOSE THAT
+; DID NOT MATCH.  EITHER WAY, TBI THEN ADDS THE 'STEP' TO
+; THAT VARIABLE AND CHECK THE RESULT WITH THE LIMIT.  IF IT
+; IS WITHIN THE LIMIT, CONTROL LOOPS BACK TO THE COMMAND
+; FOLLOWING THE 'FOR'.  IF OUTSIDE THE LIMIT, THE SAVE AREA
+; IS PURGED AND EXECUTION CONTINUES.
+;*************************************************************
+
+FOR:
+        CALL PUSHA                      ;SAVE THE OLD SAVE AREA
+        CALL SETVAL                     ;SET THE CONTROL VAR.
+        DEC HL                          ;HL IS ITS ADDRESS
+        LD (LOPVAR),HL                  ;SAVE THAT
+        LD HL,TAB5-1                    ;USE 'EXEC' TO LOOK
+        JP EXEC                         ;FOR THE WORK 'TO'
+FR1:
+        RST 18H                         ;EVALUATE THE LIMITE
+        LD (LOPLMT),HL                  ;SAVE THAT
+        LD HL,TAB6-1                    ;USE 'EXEC' TO LOOK
+        JP EXEC                         ;FOR THE WORD 'STEP'
+FR2:
+        RST 18H                         ;FOUND IT, GET STEP
+        JR FR4
+FR3:
+        LD HL,0001H                     ;NOT FOUND, SET TO 1
+FR4:
+        LD (LOPINC),HL                  ;SAVE THAT TOO
+FR5:
+        LD HL,(CURRNT)                  ;SAVE CURRENT LINE #
+        LD (LOPLN),HL
+        EX DE,HL                        ;AND TEXT POINTER
+        LD (LOPPT),HL
+        LD BC,0AH                       ;DIG INTO STACK TO
+        LD HL,(LOPVAR)                  ;FIND 'LOPVAR'
+        EX DE,HL
+        LD H,B
+        LD L,B                          ;HL=0 NOW
+        ADD HL,SP                       ;HERE IS THE STACK
+        DB 3EH                          ;DISASSEMBLY SAID "ld a,09h"
+FR7:
+        ADD HL,BC                       ;EACH LEVEL IS 10 DEEP - DIS = 09
+        LD A,(HL)                       ;GET THAT OLD 'LOPVAR'
+        INC HL
+        OR (HL)
+        JR Z,FR8                        ;0 SAYS NO MORE IN IT
+        LD A,(HL)
+        DEC HL
+        CP D                            ;SAME AS THIS ONE?
+        JR NZ,FR7
+        LD A,(HL)                       ;THE OTHER HALF?
+        CP E
+        JR NZ,FR7
+        EX DE,HL                        ;YES, FOUND ONE
+        LD HL,0000H
+        ADD HL,SP                       ;TRY TO MOVE SP
+        LD B,H
+        LD C,L
+        LD HL,000AH
+        ADD HL,DE
+        CALL MVDOWN                     ;AND PURGE 10 WORDS
+        LD SP,HL                        ;IN THE STACK
+FR8:
+        LD HL,(LOPPT)                   ;JOB DONE, RESTORE DE
+        EX DE,HL
+        RST 30H                         ;AND CONTINUE
+;
+NEXT:
+        RST 38H                         ;GET ADDRESS OF VAR.
+        JP C,QWHAT                      ;NO VARIABLE, "WHAT?"
+        LD (VARNXT),HL                  ;YES, SAVE IT
+NX0:
+        PUSH DE                         ;SAVE TEXT POINTER
+        EX DE,HL
+        LD HL,(LOPVAR)                  ;GET VAR. IN 'FOR'
+        LD A,H
+        OR L                            ;0 SAYS NEVER HAD ONE
+        JP Z,AWHAT                      ;SO WE ASK: "WHAT?"
+        RST 20H                         ;ELSE WE CHECK THEM
+        JR Z,NX3                        ;OK, THEY AGREE
+        POP DE                          ;NO, LET'S SEE
+        CALL POPA                       ;PURGE CURRENT LOOP
+        LD HL,(VARNXT)                  ;AND POP ONE LEVEL
+        JR NX0                          ;GO CHECK AGAIN
+NX3:
+        LD E,(HL)                       ;COME HERE WHEN AGREED
+        INC HL
+        LD D,(HL)                       ;DE=VALUE OF VAR.
+        LD HL,(LOPINC)
+        PUSH HL
+        LD A,H
+        XOR D
+        LD A,D
+        ADD HL,DE                       ;ADD ONE STEP
+        JP M,NX4
+        XOR H
+        JP M,NX5
+NX4:
+        EX DE,HL
+        LD HL,(LOPVAR)                  ;PUT IT BACK
+        LD (HL),E
+        INC HL
+        LD (HL),D
+        LD HL,(LOPLMT)                  ;HL->LIMIT
+        POP AF                          ;OLD HL
+        OR A
+        JP P,NX1                        ;STEP > 0
+        EX DE,HL                        ;STEP < 0
+NX1:
+        CALL CKHLDE                     ;COMPARE WITH LIMIT
+        POP DE                          ;RESTORE TEXT POINTER
+        JR C,NX2                        ;OUTSIDE LIMIT
+        LD HL,(LOPLN)                   ;WITHIN LIMIT, GO
+        LD (CURRNT),HL                  ;BACK TO THE SAVED
+        LD HL,(LOPPT)                   ;'CURRNT' AND TEXT
+        EX DE,HL                        ;POINTER
+        RST 30H
+NX5:
+        POP HL
+        POP DE
+NX2:
+        CALL POPA                       ;PURGE THIS LOOP
+        RST 30H
+
+;*************************************************************
+;
+; *** REM *** IF *** INPUT *** & LET (& DEFLT) ***
+;
+; 'REM' CAN BE FOLLOWED BY ANYTHING AND IS IGNORED BY TBI.
+; TBI TREATS IT LIKE AN 'IF' WITH A FALSE CONDITION.
+;
+; 'IF' IS FOLLOWED BY AN EXPR. AS A CONDITION AND ONE OR MORE
+; COMMANDS (INCLUDING OTHER 'IF'S) SEPERATED BY SEMI-COLONS.
+; NOTE THAT THE WORD 'THEN' IS NOT USED.  TBI EVALUATES THE
+; EXPR. IF IT IS NON-ZERO, EXECUTION CONTINUES.  IF THE
+; EXPR. IS ZERO, THE COMMANDS THAT FOLLOWS ARE IGNORED AND
+; EXECUTION CONTINUES AT THE NEXT LINE.
+;
+; 'INPUT' COMMAND IS LIKE THE 'PRINT' COMMAND, AND IS FOLLOWED
+; BY A LIST OF ITEMS.  IF THE ITEM IS A STRING IN SINGLE OR
+; DOUBLE QUOTES, OR IS A BACK-ARROW, IT HAS THE SAME EFFECT AS
+; IN 'PRINT'.  IF AN ITEM IS A VARIABLE, THIS VARIABLE NAME IS
+; PRINTED OUT FOLLOWED BY A COLON.  THEN TBI WAITS FOR AN
+; EXPR. TO BE TYPED IN.  THE VARIABLE IS THEN SET TO THE
+; VALUE OF THIS EXPR.  IF THE VARIABLE IS PROCEDED BY A STRING
+; (AGAIN IN SINGLE OR DOUBLE QUOTES), THE STRING WILL BE
+; PRINTED FOLLOWED BY A COLON.  TBI THEN WAITS FOR INPUT EXPR.
+; AND SET THE VARIABLE TO THE VALUE OF THE EXPR.
+;
+; IF THE INPUT EXPR. IS INVALID, TBI WILL PRINT "WHAT?",
+; "HOW?" OR "SORRY" AND REPRINT THE PROMPT AND REDO THE INPUT.
+; THE EXECUTION WILL NOT TERMINATE UNLESS YOU TYPE CONTROL-C.
+; THIS IS HANDLED IN 'INPERR'.
+;
+; 'LET' IS FOLLOWED BY A LIST OF ITEMS SEPERATED BY COMMAS.
+; EACH ITEM CONSISTS OF A VARIABLE, AN EQUAL SIGN, AND AN EXPR.
+; TBI EVALUATES THE EXPR. AND SET THE VARIABLE TO THAT VALUE.
+; TBI WILL ALSO HANDLE 'LET' COMMAND WITHOUT THE WORD 'LET'.
+; THIS IS DONE BY 'DEFLT'.
+;*************************************************************
+
+REM:
+        LD HL,0000H                     ;*** REM ***
+        DB 3EH                          ;THIS IS LIKE 'IF 0'
+IFF:
+        RST 18H                         ;*** IF ***
+        LD A,H                          ;IS THE EXPR.=0?
+        OR L
+        JP NZ,RUNSML                    ;NO, CONTINUE
+        CALL FNDSKP                     ;YES, SKIP REST OF LINE
+        JP NC,RUNTSL                    ;AND RUN THE NEXT LINE
+        JP RSTART                       ;IF NO NEXT, RE-START
+INPERR:
+        LD HL,(STKINP)                  ;*** INPERR ***
+        LD SP,HL                        ;RESTORE OLD SP
+        POP HL                          ;AND OLD 'CURRNT'
+        LD (CURRNT),HL
+        POP DE                          ;AND OLD TEXT POINTER
+        POP DE                          ;REDO INPUT
+INPUT:                                  ;*** INPUT ***
+IP1:
+        PUSH DE                         ;SAVE IN CASE OF ERROR
+        CALL QTSTG                      ;IS NEXT ITEM A STRING?
+        JR IP2                          ;NO
+        RST 38H                         ;YES, BUT FOLLOWED BY A
+        JR C,IP4                        ;VARIABLE? NO.
+        JR IP3                          ;YES. INPUT VARIABLE
+IP2:
+        PUSH DE                         ;SAVE FOR 'PRTSTG'
+        RST 38H                         ;MUST BE VARIABLE NOW
+        JP C,QWHAT                      ;"WHAT?" IT IS NOT?
+        LD A,(DE)                       ;GET READY FOR 'PRTSTR'
+        LD C,A
+        SUB A
+        LD (DE),A
+        POP DE
+        CALL PRTSTG                     ;PRINT STRING AS PROMPT
+        LD A,C                          ;RESTORE TEXT
+        DEC DE
+        LD (DE),A
+IP3:
+        PUSH DE                         ;SAVE TEXT POINTER
+        EX DE,HL
+        LD HL,(CURRNT)                  ;ALSO SAVE 'CURRNT'
+        PUSH HL
+        LD HL,IP1                       ;A NEGATIVE NUMBER
+        LD (CURRNT),HL                  ;AS A FLAG
+        LD HL,0000H                     ;SAVE SP TOO
+        ADD HL,SP
+        LD (STKINP),HL
+        PUSH DE                         ;OLD HL
+        LD A,3AH                        ;PRINT THIS TOO
+        CALL GETLN                      ;AND GET A LINE
+        LD DE,BUFFER                    ;POINTS TO BUFFER
+        RST 18H                         ;EVALUATE INPUT
+        NOP                             ;CAN BE 'CALL ENDCHK'
+        NOP
+        NOP
+        POP DE                          ;OK,GET OLD HL
+        EX DE,HL
+        LD (HL),E                       ;SAVE VALUE IN VAR.
+        INC HL
+        LD (HL),D
+        POP HL                          ;GET OLD 'CURRNT'
+        LD (CURRNT),HL
+        POP DE                          ;AND OLD TEXT POINTER
+IP4:
+        POP AF                          ;PURGE JUNK IN STACK
+        RST 08H                         ;IS NEXT CH. ','?
+        DB ','
+        DB IP5-$-1
+        JR IP1                          ;YES, MORE ITEMS.
+IP5:
+        RST 30H
+DEFLT:
+        LD A,(DE)                       ;***  DEFLT ***
+        CP CR                           ;EMPTY LINE IS OK
+        JR Z,LT1                        ;ELSE IT IS 'LET'
+LET:
+        CALL SETVAL                     ;*** LET ***
+        RST 08H                         ;SET VALUE TO VAR
+        DB ','                          ;---DISASSEMBLE = INC L
+        DB LT1-$-1                      ;---DISASSEMBLE = INC BC
+        JR LET                          ;ITEM BY ITEM
+LT1:
+        RST 30H                         ;UNTIL FINISH
+;*************************************************************
+;
+; *** EXPR ***
+;
+; 'EXPR' EVALUATES ARITHMETICAL OR LOGICAL EXPRESSIONS.
+; <EXPR>::<EXPR2>
+;         <EXPR2><REL.OP.><EXPR2>
+; WHERE <REL.OP.> IS ONE OF THE OPERATORS IN TAB8 AND THE
+; RESULT OF THESE OPERATIONS IS 1 IF TRUE AND 0 IF FALSE.
+; <EXPR2>::=(+ OR -)<EXPR3>(+ OR -<EXPR3>)(....)
+; WHERE () ARE OPTIONAL AND (....) ARE OPTIONAL REPEATS.
+; <EXPR3>::=<EXPR4>(* OR /><EXPR4>)(....)
+; <EXPR4>::=<VARIABLE>
+;           <FUNCTION>
+;           (<EXPR>)
+; <EXPR> IS RECURSIVE SO THAT VARIABLE '@' CAN HAVE AN <EXPR>
+; AS INDEX, FUNCTIONS CAN HAVE AN <EXPR> AS ARGUMENTS, AND
+; <EXPR4> CAN BE AN <EXPR> IN PARANTHESE.
+;*************************************************************
+
+EXPR1:
+        LD HL,TAB8-1                    ;LOOKUP REL.OP.
+        JP EXEC                         ;GO DO IT
+XP11:
+        CALL XP18                       ;REL.OP.">="
+        RET C                           ;NO, RETURN HL=0
+        LD L,A                          ;YES, RETURN HL=1
+        RET
+XP12:
+        CALL XP18                       ;REL.OP."#"
+        RET Z                           ;FALSE, RETURN HL=0
+        LD L,A                          ;TRUE, RETURN HL=1
+        RET
+XP13:
+        CALL XP18                       ;REL.OP.">"
+        RET Z                           ;FALSE
+        RET C                           ;ALSO FALSE, HL=0
+        LD L,A                          ;TRUE, HL=1
+        RET
+XP14:
+        CALL XP18                       ;REL.OP."<="
+        LD L,A                          ;SET HL=1
+        RET Z                           ;REL. TRUE, RETURN
+        RET C
+        LD L,H                          ;ELSE SET HL=0
+        RET
+XP15:
+        CALL XP18                       ;REL.OP."="
+        RET NZ                          ;FALSE, RETURN HL=0
+        LD L,A                          ;ELSE SET HL=1
+        RET
+XP16:
+        CALL XP18                       ;REL.OP."<"
+        RET NC                          ;FALSE, RETURN HL=0
+        LD L,A                          ;ELSE SET HL=1
+        RET
+XP17:
+        POP HL                          ;NOT .REL.OP
+        RET                             ;RETURN HL=<EXPR2>
+XP18:
+        LD A,C                          ;SUBROUTINE FOR ALL
+        POP HL                          ;REL.OP.'S
+        POP BC
+        PUSH HL                         ;REVERSE TOP OF STACK
+        PUSH BC
+        LD C,A
+        CALL EXPR2                      ;GET 2ND <EXPR2>
+        EX DE,HL                        ;VALUE IN DE NOW
+        EX (SP),HL                      ;1ST <EXPR2> IN HL
+        CALL CKHLDE                     ;COMPARE 1ST WITH 2ND
+        POP DE                          ;RESTORE TEXT POINTER
+        LD HL,0000H                     ;SET HL=0, A=1
+        LD A,01H
+        RET
+EXPR2:
+        RST 08H                         ;NEGATIVE SIGN?
+        DB '-'
+        DB XP21-$-1
+        LD HL,0000H                     ;YES, FAKE '0-'
+        JR XP26                         ;TREAT LIKE SUBTRACT
+XP21:
+        RST 08H                         ;POSITIVE SIGN? IGNORE
+        DB '+'
+        DB XP22-$-1
+XP22:
+        CALL EXPR3                      ;1ST <EXPR3>
+XP23:
+        RST 08H                         ;ADD?
+        DB  '+'
+        DB XP25-$-1
+        PUSH HL                         ;YES, SAVE VALUE
+        CALL EXPR3                      ;GET 2ND <EXPR3>
+XP24:
+        EX DE,HL                        ;2ND IN DE
+        EX (SP),HL                      ;1ST IN HL
+        LD A,H                          ;COMPARE SIGN
+        XOR D
+        LD A,D
+        ADD HL,DE
+        POP DE                          ;RESTORE TEXT POINTER
+        JP M,XP23                       ;1ST AND 2ND SIGN DIFFER
+        XOR H                           ;1ST AND 2ND SIGN EQUAL
+        JP P,XP23                       ;SO IS RESULT
+        JP QHOW                         ;ELSE WE HAVE OVERFLOW
+XP25:
+        RST 08H                         ;SUBTRACT?
+        DB '-'
+        DB XP42-$-1
+XP26:
+        PUSH HL                         ;YES, SAVE 1ST <EXPR3>
+        CALL EXPR3                      ;GET 2ND <EXPR3>
+        CALL CHGSGN                     ;NEGATE
+        JR XP24                         ;AND ADD THEM
+;
+EXPR3:
+        CALL EXPR4                      ;GET 1ST <EXPR4>
+XP31:
+        RST 08H                         ;MULTIPLY?
+        DB '*'
+        DB XP34-$-1
+        PUSH HL                         ;YES, SAVE 1ST
+        CALL EXPR4                      ;AND GET 2ND <EXPR4>
+        LD B,00H                        ;CLEAR B FOR SIGN
+        CALL CHKSGN                     ;CHECK SIGN
+        EX (SP),HL                      ;1ST IN HL
+        CALL CHKSGN                     ;CHECK SIGN OF 1ST
+        EX DE,HL
+        EX (SP),HL
+        LD A,H                          ;IS HL > 255 ?
+        OR A
+        JR Z,XP32                       ;NO
+        LD A,D                          ;YES, HOW ABOUT DE
+        OR D
+        EX DE,HL                        ;PUT SMALLER IN HL
+        JP NZ,AHOW                      ;ALSO >, WILL OVERFLOW
+XP32:
+        LD A,L                          ;THIS IS DUMB
+        LD HL,0000H                     ;CLEAR RESULT
+        OR A                            ;ADD AND COUNT
+        JR Z,XP35
+XP33:
+        ADD HL,DE
+        JP C,AHOW                       ;OVERFLOW
+        DEC A
+        JR NZ,XP33
+        JR XP35                         ;FINISHED
+XP34:
+        RST 08H                         ;DIVIDE?
+        DB '/'
+        DB XP42-$-1
+        PUSH HL                         ;YES, SAVE 1ST <EXPR4>
+        CALL EXPR4                      ;AND GET THE SECOND ONE
+        LD B,00H                        ;CLEAR B FOR SIGN
+        CALL CHKSGN                     ;CHECK SIGN OF 2ND
+        EX (SP),HL                      ;GET 1ST IN HL
+        CALL CHKSGN                     ;CHECK SIGN OF 1ST
+        EX DE,HL
+        EX (SP),HL
+        EX DE,HL
+        LD A,D                          ;DIVIDE BY 0?
+        OR E
+        JP Z,AHOW                       ;SAY "HOW?"
+        PUSH BC                         ;ELSE SAVE SIGN
+        CALL DIVIDE                     ;USE SUBROUTINE
+        LD H,B                          ;RESULT IN HL NOW
+        LD L,C
+        POP BC                          ;GET SIGN BACK
+XP35:
+        POP DE                          ;AND TEXT POINTER
+        LD A,H                          ;HL MUST BE +
+        OR A
+        JP M,QHOW                       ;ELSE IT IS OVERFLOW
+        LD A,B
+        OR A
+        CALL M,CHGSGN                   ;CHANGE SIGN IF NEEDED
+        JR XP31                         ;LOOK FOR MORE TERMS
+EXPR4:
+        LD HL,TAB4-1                    ;FIND FUNCTION IN TAB4
+        JP EXEC                         ;AND GO DO IT
+XP40:
+        RST 38H                         ;NO, NOT A FUNCTION
+        JR C,XP41                       ;NOR A VARIABLE
+        LD A,(HL)                       ;VARIABLE
+        INC HL
+        LD H,(HL)                       ;VALUE IN HL
+        LD L,A
+        RET
+XP41:
+        CALL TSTNUM                     ;OR IS IT A NUMBER
+        LD A,B                          ;# OF DIGIT
+        OR A
+        RET NZ                          ;OK
+PARN:
+        RST 08H
+        DB '('
+        DB XP43-$-1
+        RST 18H                         ;"(EXPR)"
+        RST 08H
+        DB ')'
+        DB XP43-$-1
+XP42:
+        RET
+XP43:
+        JP QWHAT                        ;ELSE SAY: "WHAT?"
+RND:
+        CALL PARN                       ;*** RND(EXPR) ***
+        LD A,H                          ;EXPR MUST BE +
+        OR A
+        JP M,QHOW
+        OR L                            ;AND NON-ZERO
+        JP Z,QHOW
+        PUSH DE                         ;SAVE BOTH
+        PUSH HL
+        LD HL,(RANPNT)                  ;GET MEMORY AS RANDOM
+        LD DE,LSTROM                    ;NUMBER
+        RST 20H
+        JR C,RA1                        ;WRAP AROUND IF LAST
+        LD HL,START
+RA1:
+        LD E,(HL)
+        INC HL
+        LD D,(HL)
+        LD (RANPNT),HL
+        POP HL
+        EX DE,HL
+        PUSH BC
+        CALL DIVIDE                     ;RND (N)=MOD(M,N)+1
+        POP BC
+        POP DE
+        INC HL
+        RET
+ABS:
+        CALL PARN                       ;*** ABS (EXPR) ***
+        DEC DE
+        CALL CHKSGN                     ;CHECK SIGN
+        INC DE
+        RET
+SIZE:
+        LD HL,(TXTUNF)                  ;*** SIZE ***
+        PUSH DE                         ;GET THE NUMBER OF FREE
+        EX DE,HL                        ;BYTES BETWEEN 'TXTUNF'
+        LD HL,VARBGN                    ;AND 'VARBGN'
+        CALL SUBDE
+        POP DE
+        RET
+;*************************************************************
+;
+; *** DIVIDE *** SUBDE *** CHKSGN *** CHGSGN *** & CKHLDE ***
+;
+; 'DIVIDE' DIVIDES HL BY DE, RESULT IN BC, REMAINDER IN HL
+;
+; 'SUBDE' SUBSTRACTS DE FROM HL
+;
+; 'CHKSGN' CHECKS SIGN OF HL.  IF +, NO CHANGE.  IF -, CHANGE
+; SIGN AND FLIP SIGN OF B.
+;
+; 'CHGSGN' CHECKS SIGN N OF HL AND B UNCONDITIONALLY.
+;
+; 'CKHLDE' CHECKS SIGN OF HL AND DE.  IF DIFFERENT, HL AND DE
+; ARE INTERCHANGED.  IF SAME SIGN, NOT INTERCHANGED.  EITHER
+; CASE, HL DE ARE THEN COMPARED TO SET THE FLAGS.
+;*************************************************************
+
+DIVIDE:
+        PUSH HL                         ;*** DIVIDE ***
+        LD L,H                          ;DIVIDE H BY DE
+        LD H,00H
+        CALL DV1
+        LD B,C                          ;SAVE RESULT IN B
+        LD A,L                          ;(REMAINDER+L)/DE
+        POP HL
+        LD H,A
+DV1:
+        LD C,0FFH                       ;RESULT IN C
+DV2:
+        INC C                           ;DUMB ROUTINE
+        CALL SUBDE                      ;DIVIDE BY SUBTRACT
+        JR NC,DV2                       ;AND COUNT
+        ADD HL,DE
+        RET
+SUBDE:
+        LD A,L                          ;*** SUBDE ***
+        SUB E                           ;SUBSTRACT DE FROM
+        LD L,A                          ;HL
+        LD A,H
+        SBC A,D
+        LD H,A
+        RET
+CHKSGN:
+        LD A,H                          ;*** CHKSGN ***
+        OR A                            ;CHECK SIGN OF HL
+        RET P
+CHGSGN:
+        LD A,H                          ;*** CHGSGN ***
+        PUSH AF
+        CPL                             ;CHANGE SIGN OF HL
+        LD H,A
+        LD A,L
+        CPL
+        LD L,A
+        INC HL
+        POP AF
+        XOR H
+        JP P,QHOW
+        LD A,B                          ;AND ALSO FLIP B
+        XOR 80H
+        LD B,A
+        RET
+CKHLDE:
+        LD A,H                          ;SAME SIGN?
+        XOR D                           ;YES, COMPARE
+        JP P,CK1                        ;NO, XCHANGE AND COMP
+        EX DE,HL
+CK1:
+        RST 20H
+        RET
+;*************************************************************
+;
+; *** SETVAL *** FIN *** ENDCHK *** & ERROR (& FRIENDS) ***
+;
+; "SETVAL" EXPECTS A VARIABLE, FOLLOWED BY AN EQUAL SIGN AND
+; THEN AN EXPR.  IT EVALUATES THE EXPR. AND SET THE VARIABLE
+; TO THAT VALUE.
+;
+; "FIN" CHECKS THE END OF A COMMAND.  IF IT ENDED WITH ";",
+; EXECUTION CONTINUES.  IF IT ENDED WITH A CR, IT FINDS THE
+; NEXT LINE AND CONTINUE FROM THERE.
+;
+; "ENDCHK" CHECKS IF A COMMAND IS ENDED WITH CR.  THIS IS
+; REQUIRED IN CERTAIN COMMANDS.  (GOTO, RETURN, AND STOP ETC.)
+;
+; "ERROR" PRINTS THE STRING POINTED BY DE (AND ENDS WITH CR).
+; IT THEN PRINTS THE LINE POINTED BY 'CURRNT' WITH A "?"
+; INSERTED AT WHERE THE OLD TEXT POINTER (SHOULD BE ON TOP
+; OF THE STACK) POINTS TO.  EXECUTION OF TB IS STOPPED
+; AND TBI IS RESTARTED.  HOWEVER, IF 'CURRNT' -> ZERO
+; (INDICATING A DIRECT COMMAND), THE DIRECT COMMAND IS NOT
+; PRINTED.  AND IF 'CURRNT' -> NEGATIVE # (INDICATING 'INPUT'
+; COMMAND), THE INPUT LINE IS NOT PRINTED AND EXECUTION IS
+; NOT TERMINATED BUT CONTINUED AT 'INPERR'.
+;
+; RELATED TO 'ERROR' ARE THE FOLLOWING:
+; 'QWHAT' SAVES TEXT POINTER IN STACK AND GET MESSAGE "WHAT?"
+; 'AWHAT' JUST GET MESSAGE "WHAT?" AND JUMP TO 'ERROR'.
+; 'QSORRY' AND 'ASORRY' DO SAME KIND OF THING.
+; 'AHOW' AND 'AHOW' IN THE ZERO PAGE SECTION ALSO DO THIS.
+;*************************************************************
+
+SETVAL:
+        RST 38H                         ;*** SETVAL ***
+        JP C,QWHAT                      ;"WHAT?" NO VARIABLE
+        PUSH HL                         ;SAVE ADDRESS OF VAR.
+        RST 08H                         ;PASS "=" SIGN
+        DB '='
+        DB SV1-$-1
+        RST 18H                         ;EVALUATE EXPR.
+        LD B,H                          ;VALUE IS IN BC NOW
+        LD C,L
+        POP HL                          ;GET ADDRESS
+        LD (HL),C                       ;SAVE VALUE
+        INC HL
+        LD (HL),B
+        RET
+SV1:
+        JP QWHAT                        ;NO "=" SIGN
+FIN:
+        RST 08H                         ;*** FIN ***
+        DB 3BH
+        DB FI1-$-1
+        POP AF                          ;";", PURGE RET. ADDR.
+        JP RUNSML                       ;CONTINUE SAME LINE
+FI1:
+        RST 08H                         ;NOT ";", IS IT CR?
+        DB CR
+        DB FI2-$-1
+        POP AF                          ;YES, PURGE RET. ADDR.
+        JP RUNNXL                       ;RUN NEXT LINE
+FI2:
+        RET                             ;ELSE RETURN TO CALLER
+ENDCHK:
+        RST 28H                         ;*** ENDCHK ***
+        CP CR                           ;END WITH CR?
+        RET Z                           ;OK, ELSE SAY: "WHAT?"
+QWHAT:
+        PUSH DE                         ;*** QWHAT ***
+AWHAT:
+        LD DE,WHAT                      ;*** AWHAT ***
+ERROR_ROUTINE:
+        SUB A                           ;*** ERROR ***
+        CALL PRTSTG                     ;PRINT 'WHAT?', 'HOW?'
+        POP DE                          ;OR 'SORRY'
+        LD A,(DE)                       ;SAVE THE CHARACTER
+        PUSH AF                         ;AT WHERE OLD DE ->
+        SUB A                           ;AND PUT A 0 THERE
+        LD (DE),A
+        LD HL,(CURRNT)                  ;GET CURRENT LINE #
+        PUSH HL
+        LD A,(HL)                       ;CHECK THE VALUE
+        INC HL
+        OR (HL)
+        POP DE
+        JP Z,RSTART                     ;IF ZERO, JUST RESTART
+        LD A,(HL)                       ;IF NEGATIVE,
+        OR A
+        JP M,INPERR                     ;REDO INPUT
+        CALL PRTLN                      ;ELSE PRINT THE LINE
+        DEC DE                          ;UPTO WHERE THE 0 IS
+        POP AF                          ;RESTORE THE CHARACTER
+        LD (DE),A
+        LD A,3FH                        ;PRINT A "?"
+        RST 10H
+        SUB A                           ;AND THE REST OF THE
+        CALL PRTSTG                     ;LINE
+        JP RSTART                       ;THEN RESTART
+QSORRY:
+        PUSH DE                         ;*** QSORRY ***
+ASORRY:
+        LD DE,SORRY                     ;*** ASORRY ***
+        JR ERROR_ROUTINE
+;*************************************************************
+;
+; *** GETLN *** FNDLN (& FRIENDS) ***
+;
+; 'GETLN' READS A INPUT LINE INTO 'BUFFER'.  IT FIRST PROMPT
+; THE CHARACTER IN A (GIVEN BY THE CALLER), THEN IT FILLS
+; THE BUFFER AND ECHOS.  IT IGNORES LF'S AND NULLS, BUT STILL
+; ECHOS THEM BACK.  RUB-OUT IS USED TO CAUSE IT TO DELETE
+; THE LAST CHARACTER (IF THERE IS ONE), AND ALT-MOD IS USED TO
+; CAUSE IT TO DELETE THE WHOLE LINE AND START IT ALL OVER.
+; CR SIGNALS THE END OF A LINE, AND CAUSE 'GETLN' TO RETURN.
+;
+; 'FNDLN' FINDS A LINE WITH A GIVEN LINE # (IN HL) IN THE
+; TEXT SAVE AREA.  DE IS USED AS THE TEXT POINTER.  IF THE
+; LINE IS FOUND, DE WILL POINT TO THE BEGINNING OF THAT LINE
+; (I.E., THE LOW BYTE OF THE LINE #), AND FLAGS ARE NC & Z.
+; IF THAT LINE IS NOT THERE AND A LINE WITH A HIGHER LINE #
+; IS FOUND, DE POINTS TO THERE AND FLAGS ARE NC & NZ.  IF
+; WE REACHED THE END OF TEXT SAVE AREA AND CANNOT FIND THE
+; LINE, FLAGS ARE C & NZ.
+; 'FNDLN' WILL INITIALIZE DE TO THE BEGINNING OF THE TEXT SAVE
+; AREA TO START THE SEARCH.  SOME OTHER ENTRIES OF THIS
+; ROUTINE WILL NOT INITIALIZE DE AND DO THE SEARCH.
+; 'FNDLNP' WILL START WITH DE AND SEARCH FOR THE LINE #.
+; 'FNDNXT' WILL BUMP DE BY 2, FIND A CR AND THEN START SEARCH.
+; 'FNDSKP' USE DE TO FIND A CR, AND THEN START SEARCH.
+;*************************************************************
+
+GETLN:
+        RST 10H                         ;*** GETLN ***
+        LD DE,BUFFER                    ;PROMPT AND INIT.
+GL1:
+        CALL CHKIO                      ;CHECK KEYBOARD
+        JR Z,GL1                        ;NO INPUT, WAIT
+        CP 7FH                          ;DELETE LAST CHARACTER?
+        JR Z,GL3                        ;YES
+        RST 10H                         ;INPUT, ECHO BACK
+        CP 0AH                          ;IGNORE LF
+        JR Z,GL1
+        OR A                            ;IGNORE NULL
+        JR Z,GL1
+        CP 7DH                          ;DELETE THE WHOLE LINE?
+        JR Z,GL4                        ;YES
+        LD (DE),A                       ;ELSE SAVE INPUT
+        INC DE                          ;AND BUMP POINTER
+        CP 0DH                          ;WAS IT CR
+        RET Z                           ;YES, END OF LINE
+        LD A,E                          ;ELSE MORE FREE ROOM?
+        CP BUFEND & 0FFH
+        JR NZ,GL1                       ;YES, GET NEXT INPUT
+GL3:
+        LD A,E                          ;DELETE LAST CHARACTER
+        CP BUFFER & 0FFH                ;BUT DO WE HAVE ANY?
+        JR Z,GL4                        ;NO, REDO WHOLE LINE
+        DEC DE                          ;YES, BACKUP POINTER
+        LD A,5CH                        ;AND ECHO A BACK-SLASH
+        RST 10H
+        JR GL1                          ;GO GET NEXT INPUT
+GL4:
+        CALL CRLF                       ;REDO ENTIRE LINE
+        LD A,05EH                       ;CR, LF AND UP-ARROW
+        JR GETLN
+FNDLN:
+        LD A,H                          ;*** FNDLN ***
+        OR A                            ;CHECK SIGN OF HL
+        JP M,QHOW                       ;IT CANNOT BE -
+        LD DE,TXTBGN                    ;INIT TEXT POINTER
+FNDLP:                                  ;*** FDLNP ***
+FL1:
+        PUSH HL                         ;SAVE LINE #
+        LD HL,(TXTUNF)                  ;CHECK IF WE PASSED END
+        DEC HL
+        RST 20H
+        POP HL                          ;GET LINE # BACK
+        RET C                           ;C,NZ PASSED END
+        LD A,(DE)                       ;WE DID NOT, GET BYTE 1
+        SUB L                           ;IS THIS THE LINE?
+        LD B,A                          ;COMPARE LOW ORDER
+        INC DE
+        LD A,(DE)                       ;GET BYTE 2
+        SBC A,H                         ;COMPARE HIGH ORDER
+        JR C,FL2                        ;NO, NOT THERE YET
+        DEC DE                          ;ELSE WE EITHER FOUND
+        OR B                            ;IT, OR IT IS NOT THERE
+        RET                             ;NC,Z;FOUND, NC,NZ:NO
+FNDNXT:                                 ;*** FNDNXT ***
+        INC DE                          ;FIND NEXT LINE
+FL2:
+        INC DE                          ;JUST PASSED BYTE 1 & 2
+FNDSKP:
+        LD A,(DE)                       ;*** FNDSKP ***
+        CP CR                           ;TRY TO FIND CR
+        JR NZ,FL2                       ;KEEP LOOKING
+        INC DE                          ;FOUND CR, SKIP OVER
+        JR FL1                          ;CHECK IF END OF TEXT
+;*************************************************************
+;
+; *** PRTSTG *** QTSTG *** PRTNUM *** & PRTLN ***
+;
+; 'PRTSTG' PRINTS A STRING POINTED BY DE.  IT STOPS PRINTING
+; AND RETURNS TO CALLER WHEN EITHER A CR IS PRINTED OR WHEN
+; THE NEXT BYTE IS THE SAME AS WHAT WAS IN A (GIVEN BY THE
+; CALLER).  OLD A IS STORED IN B, OLD B IS LOST.
+;
+; 'QTSTG' LOOKS FOR A BACK-ARROW, SINGLE QUOTE, OR DOUBLE
+; QUOTE.  IF NONE OF THESE, RETURN TO CALLER.  IF BACK-ARROW,
+; OUTPUT A CR WITHOUT A LF.  IF SINGLE OR DOUBLE QUOTE, PRINT
+; THE STRING IN THE QUOTE AND DEMANDS A MATCHING UNQUOTE.
+; AFTER THE PRINTING THE NEXT 3 BYTES OF THE CALLER IS SKIPPED
+; OVER (USUALLY A JUMP INSTRUCTION.
+;
+; 'PRTNUM' PRINTS THE NUMBER IN HL.  LEADING BLANKS ARE ADDED
+; IF NEEDED TO PAD THE NUMBER OF SPACES TO THE NUMBER IN C.
+; HOWEVER, IF THE NUMBER OF DIGITS IS LARGER THAN THE # IN
+; C, ALL DIGITS ARE PRINTED ANYWAY.  NEGATIVE SIGN IS ALSO
+; PRINTED AND COUNTED IN, POSITIVE SIGN IS NOT.
+;
+; 'PRTLN' PRINTS A SAVED TEXT LINE WITH LINE # AND ALL.
+;*************************************************************
+
+PRTSTG:
+        LD B,A                          ;*** PRTSTG ***
+PS1:
+        LD A,(DE)                       ;GET A CHARACTER
+        INC DE                          ;BUMP POINTER
+        CP B                            ;SAME AS OLD A?
+        RET Z                           ;YES, RETURN
+        RST 10H                         ;NO, NEXT
+        CP CR                           ;WAS IT A CR?
+        JR NZ,PS1                       ;NO, NEXT
+        RET                             ;YES, RETURN
+QTSTG:
+        RST 08H                         ;*** QTSTG ***
+        DB '"'
+        DB QT3-$-1
+        LD A,22H                        ;IT IS A "
+QT1:
+        CALL PRTSTG                     ;PRINT UNTIL ANOTHER
+        CP CR                           ;WAS LAST ONE A CR?
+        POP HL                          ;RETURN ADDRESS
+        JP Z,RUNNXL                     ;WAS CR, RUN NEXT LINE
+QT2:
+        INC HL                          ;SKIP 3 BYTES ON RETURN
+        INC HL
+        INC HL
+        JP (HL)                         ;RETURN
+QT3:
+        RST 08H                         ;IS IT A '?
+        DB 27H
+        DB QT4-$-1
+        LD A,27H                        ;YES, DO THE SAME
+        JR QT1                          ;AS IN "
+QT4:
+        RST 08H                         ;IS IT BACK-ARROW?
+        DB 5FH
+        DB QT5-$-1
+        LD A,8DH                        ;YES, CR WITHOUT LF
+        RST 10H                         ;DO IT TWICE TO GIVE
+        RST 10H                         ;TTY ENOUGH TIME
+        POP HL                          ;RETURN ADDRESS
+        JR QT2
+QT5:
+        RET                             ;NONE OF ABOVE
+;
+PRTNUM:
+        LD B,00H                        ;*** PRTNUM ***
+        CALL CHKSGN                     ;CHECK SIGN
+        JP P,PN1                        ;NO SIGN
+        LD B,'-'                        ;B=SIGN
+        DEC C                           ;'-' TAKES SPACE
+PN1:
+        PUSH DE                         ;SAVE
+        LD DE,000AH                     ;DECIMAL
+        PUSH DE                         ;SAVE AS FLAG
+        DEC C                           ;C=SPACES
+        PUSH BC                         ;SAVE SIGN & SPACE
+PN2:
+        CALL DIVIDE                     ;DIVIDE HL BY 10
+        LD A,B                          ;RESULT 0?
+        OR C
+        JR Z,PN3                        ;YES, WE GOT ALL
+        EX (SP),HL                      ;NO, SAVE REMAINDER
+        DEC L                           ;AND COUNT SPACE
+        PUSH HL                         ;HL IS OLD BC
+        LD H,B                          ;MOVE RESULT TO BC
+        LD L,C
+        JR PN2                          ;AND DIVIDE BY 10
+PN3:
+        POP BC                          ;WE GOT ALL DIGITS IN
+PN4:
+        DEC C                           ;THE STACK
+        LD A,C                          ;LOOK AT SPACE COUNT
+        OR A
+        JP M,PN5                        ;NO LEADING BLANKS
+        LD A,20H                        ;LEADING BLANKS
+        RST 10H
+        JR PN4                          ;MORE?
+PN5:
+        LD A,B                          ;PRINT SIGN
+        OR A
+        CALL NZ,0010H
+        LD E,L                          ;LAST REMAINDER IN E
+PN6:
+        LD A,E                          ;CHECK DIGIT IN E
+        CP 0AH                          ;10 IS FLAG FOR NO MORE
+        POP DE
+        RET Z                           ;IF SO, RETURN
+        ADD A,30H                       ;ELSE, CONVERT TO ASCII
+        RST 10H                         ;PRINT THE DIGIT
+        JR PN6                          ;GO BACK FOR MORE
+PRTLN:
+        LD A,(DE)                       ;*** PRTLN ***
+        LD L,A                          ;LOW ORDER LINE #
+        INC DE
+        LD A,(DE)                       ;HIGH ORDER
+        LD H,A
+        INC DE
+        LD C,04H                        ;PRINT 4 DIGIT LINE #
+        CALL PRTNUM
+        LD A,20H                        ;FOLLOWED BY A BLANK
+        RST 10H
+        SUB A                           ;AND THEN THE NEXT
+        CALL PRTSTG
+        RET
+;*************************************************************
+;
+; *** MVUP *** MVDOWN *** POPA *** & PUSHA ***
+;
+; 'MVUP' MOVES A BLOCK UP FROM WHERE DE-> TO WHERE BC-> UNTIL
+; DE = HL
+;
+; 'MVDOWN' MOVES A BLOCK DOWN FROM WHERE DE-> TO WHERE HL->
+; UNTIL DE = BC
+;
+; 'POPA' RESTORES THE 'FOR' LOOP VARIABLE SAVE AREA FROM THE
+; STACK
+;
+; 'PUSHA' STACKS THE 'FOR' LOOP VARIABLE SAVE AREA INTO THE
+; STACK
+;*************************************************************
+
+MVUP:
+        RST 20H                         ;*** MVUP ***
+        RET Z                           ;DE = HL, RETURN
+        LD A,(DE)                       ;GET ONE BYTE
+        LD (BC),A                       ;MOVE IT
+        INC DE                          ;INCREASE BOTH POINTERS
+        INC BC
+        JR MVUP                         ;UNTIL DONE
+MVDOWN:
+        LD A,B                          ;*** MVDOWN ***
+        SUB D                           ;TEST IF DE = BC
+        JP NZ,MD1                       ;NO, GO MOVE
+        LD A,C                          ;MAYBE, OTHER BYTE?
+        SUB E
+        RET Z                           ;YES, RETURN
+MD1:
+        DEC DE                          ;ELSE MOVE A BYTE
+        DEC HL                          ;BUT FIRST DECREASE
+        LD A,(DE)                       ;BOTH POINTERS AND
+        LD (HL),A                       ;THEN DO IT
+        JR MVDOWN                       ;LOOP BACK
+POPA:
+        POP BC                          ;BC = RETURN ADDR.
+        POP HL                          ;RESTORE LOPVAR, BUT
+        LD (LOPVAR),HL                  ;=0 MEANS NO MORE
+        LD A,H
+        OR L
+        JR Z,PP1                        ;YEP, GO RETURN
+        POP HL                          ;NOP, RESTORE OTHERS
+        LD (LOPINC),HL
+        POP HL
+        LD (LOPLMT),HL
+        POP HL
+        LD (LOPLN),HL
+        POP HL
+        LD (LOPPT),HL
+PP1:
+        PUSH BC                         ;BC = RETURN ADDR.
+        RET
+PUSHA:
+        LD HL,STKLMT                    ;*** PUSHA ***
+        CALL CHGSGN
+        POP BC                          ;BC=RETURN ADDRESS
+        ADD HL,SP                       ;IS STACK NEAR THE TOP?
+        JP NC,QSORRY                    ;YES, SORRY FOR THAT
+        LD HL,(LOPVAR)                  ;ELSE SAVE LOOP VAR'S
+        LD A,H                          ;BUT IF LOPVAR IS 0
+        OR L                            ;THAT WILL BE ALL
+        JR Z,PU1
+        LD HL,(LOPPT)                   ;ELSE, MORE TO SAVE
+        PUSH HL
+        LD HL,(LOPLN)
+        PUSH HL
+        LD HL,(LOPLMT)
+        PUSH HL
+        LD HL,(LOPINC)
+        PUSH HL
+        LD HL,(LOPVAR)
+PU1:
+        PUSH HL
+        PUSH BC                         ;BC = RETURN ADDR.
+        RET
+;*************************************************************
+;
+; *** OUTC *** & CHKIO ***
+;
+; THESE ARE THE ONLY I/O ROUTINES IN TBI.
+; 'OUTC' IS CONTROLLED BY A SOFTWARE SWITCH 'OCSW'.  IF OCSW=0
+; 'OUTC' WILL JUST RETURN TO THE CALLER.  IF OCSW IS NOT 0,
+; IT WILL OUTPUT THE BYTE IN A.  IF THAT IS A CR, A LF IS ALSO
+; SEND OUT.  ONLY THE FLAGS MAY BE CHANGED AT RETURN. ALL REG.
+; ARE RESTORED.
+;
+; 'CHKIO' CHECKS THE INPUT.  IF NO INPUT, IT WILL RETURN TO
+; THE CALLER WITH THE Z FLAG SET.  IF THERE IS INPUT, Z FLAG
+; IS CLEARED AND THE INPUT BYTE IS IN A.  HOWEVER, IF THE
+; INPUT IS A CONTROL-O, THE 'OCSW' SWITCH IS COMPLIMENTED, AND
+; Z FLAG IS RETURNED.  IF A CONTROL-C IS READ, 'CHKIO' WILL
+; RESTART TBI AND DO NOT RETURN TO THE CALLER.
+;
+; Do not modify these routines.  Routines requiring
+; modification are : SERIAL_INIT, RX_RDY, and TX_RDY.
+;*************************************************************
+
+INIT:
+        DI
+        CALL SERIAL_INIT        ;INITIALIZE THE SIO
+        LD D,19H
+PATLOP:
+        CALL CRLF
+        DEC D
+        JR NZ,PATLOP
+        SUB A
+        LD DE,MSG1          ;PRINT THE BOOT MESSAGES
+        CALL PRTSTG
+        LD DE,MSG2
+        CALL PRTSTG
+        LD HL,START
+        LD (RANPNT),HL
+        LD HL,TXTBGN
+        LD (TXTUNF),HL
+        JP RSTART
+OUTC:
+        JR NZ,OUTC2         ;IT IS ON
+        POP AF                          ;IT IS OFF
+        RET                             ;RESTORE AF AND RETURN
+OUTC2:
+        CALL TX_RDY         ;SEE IF TRANSMIT IS AVAILABLE
+        POP AF                          ;RESTORE THE REGISTER
+        OUT (SerialPort),A      ;SEND THE BYTE
+        CP CR
+        RET NZ
+        LD A,LF
+        RST 10H
+        LD A,CR
+        RET
+CHKIO:
+        CALL RX_RDY         ;CHECK IF CHARACTER AVAILABLE
+        RET Z                           ;RETURN IF NO CHARACTER AVAILABLE
+
+        PUSH BC                         ;IF IT'S A LF, IGNORE AND RETURN
+        LD B,A                          ; AS IF THERE WAS NO CHARACTER.
+        SUB LF
+        JR Z,CHKIO2
+        LD A,B                          ;OTHERWISE RESTORE 'A' AND 'BC'
+        POP BC                          ; AND CONTINUE ON.
+
+        CP 0FH                          ;IS IT CONTROL-0?
+        JR NZ,CI1                       ;NO, MORE CHECKING
+        LD A,(OCSW)                     ;CONTROL-0 FLIPS OCSW
+        CPL                             ;ON TO OFF, OFF TO ON
+        LD (OCSW),A
+        JR CHKIO                        ;GET ANOTHER INPUT
+CHKIO2:
+        LD A,00H                        ;CLEAR A
+        OR A                            ;ZET THE Z-FLAG
+        POP BC                          ;RESTORE THE 'BC' PAIR
+        RET                             ;RETURN WITH 'Z' SET.
+CI1:
+        CP 03H                          ;IS IT CONTROL-C?
+        RET NZ                          ;NO, RETURN "NZ"
+        JP RSTART                       ;YES, RESTART TBI
+
+
+MSG1:   DB   ESC,"[2J",ESC,"[H"         ;SCREEN CLEAR
+        DB   'Z80 TINY BASIC 2.0g',CR       ;BOOT MESSAGE
+MSG2:   DB   'PORTED BY DOUG GABBARD, 2017',CR
+
+;*************************************************************
+;
+; *** TABLES *** DIRECT *** & EXEC ***
+;
+; THIS SECTION OF THE CODE TESTS A STRING AGAINST A TABLE.
+; WHEN A MATCH IS FOUND, CONTROL IS TRANSFERED TO THE SECTION
+; OF CODE ACCORDING TO THE TABLE.
+;
+; AT 'EXEC', DE SHOULD POINT TO THE STRING AND HL SHOULD POINT
+; TO THE TABLE-1.  AT 'DIRECT', DE SHOULD POINT TO THE STRING.
+; HL WILL BE SET UP TO POINT TO TAB1-1, WHICH IS THE TABLE OF
+; ALL DIRECT AND STATEMENT COMMANDS.
+;
+; A '.' IN THE STRING WILL TERMINATE THE TEST AND THE PARTIAL
+; MATCH WILL BE CONSIDERED AS A MATCH.  E.G., 'P.', 'PR.',
+; 'PRI.', 'PRIN.', OR 'PRINT' WILL ALL MATCH 'PRINT'.
+;
+; THE TABLE CONSISTS OF ANY NUMBER OF ITEMS.  EACH ITEM
+; IS A STRING OF CHARACTERS WITH BIT 7 SET TO 0 AND
+; A JUMP ADDRESS STORED HI-LOW WITH BIT 7 OF THE HIGH
+; BYTE SET TO 1.
+;
+; END OF TABLE IS AN ITEM WITH A JUMP ADDRESS ONLY.  IF THE
+; STRING DOES NOT MATCH ANY OF THE OTHER ITEMS, IT WILL
+; MATCH THIS NULL ITEM AS DEFAULT.
+;*************************************************************
+
+TAB1:                                   ;DIRECT COMMANDS
+        DB 'LIST'
+        DWA LIST
+        DB 'RUN'
+        DWA RUN
+        DB 'NEW'
+        DWA NEW
+TAB2:                                   ;DIRECT/STATEMENT
+        DB 'NEXT'
+        DWA NEXT
+        DB 'LET'
+        DWA LET
+        DB 'IF'
+        DWA IFF
+        DB 'GOTO'
+        DWA GOTO
+        DB 'GOSUB'
+        DWA GOSUB
+        DB 'RETURN'
+        DWA RETURN
+        DB 'REM'
+        DWA REM
+        DB 'FOR'
+        DWA FOR
+        DB 'INPUT'
+        DWA INPUT
+        DB 'PRINT'
+        DWA PRINT
+        DB 'STOP'
+        DWA STOP
+        DWA DEFLT
+TAB4:                                   ;FUNCTIONS
+        DB 'RND'
+        DWA RND
+        DB 'ABS'
+        DWA ABS
+        DB 'SIZE'
+        DWA SIZE
+        DWA XP40
+TAB5:                                   ;"TO" IN "FOR"
+        DB 'TO'
+        DWA FR1
+        DWA QWHAT
+TAB6:                                   ;"STEP" IN "FOR"
+        DB 'STEP'
+        DWA FR2
+        DWA FR3
+TAB8:                                   ;RELATION OPERATORS
+        DB '>='
+        DWA XP11
+        DB '#'
+        DWA XP12
+        DB '>'
+        DWA XP13
+        DB '='
+        DWA XP15
+        DB '<='
+        DWA XP14
+        DB '<'
+        DWA XP16
+        DWA XP17
+DIRECT: LD HL,TAB1-1                   ;*** DIRECT ***
+EXEC:                                   ;*** EXEC ***
+EX0:    RST 28H                         ;IGNORE LEADING BLANKS
+        PUSH DE                         ;SAVE POINTER
+EX1:
+        LD A,(DE)                       ;IF FOUND '.' IN STRING
+        INC DE                          ;BEFORE ANY MISMATCH
+        CP 23H                          ;WE DECLARE A MATCH
+        JR Z,EX3
+        INC HL                          ;HL->TABLE
+        CP (HL)                         ;IF MATCH, TEST NEXT
+        JR Z,EX1
+        LD A,7FH                        ;ELSE SEE IF BIT 7
+        DEC DE                          ;OF TABLE IS SET, WHICH
+        CP (HL)                         ;IS THE JUMP ADDR. (HI)
+        JR C,EX5                        ;C:YES, MATCHED
+EX2:
+        INC HL                          ;NC:NO, FIND JUMP ADDR.
+        CP (HL)
+        JR NC,EX2
+        INC HL                          ;BUMP TO NEXT TAB. ITEM
+        POP DE                          ;RESTORE STRING POINTER
+        JR EX0                          ;TEST AGAINST NEXT ITEM
+EX3:
+        LD A,7FH                        ;PARTIAL MATCH, FIND
+EX4:
+        INC HL                          ;JUMP ADDR., WHICH IS
+        CP (HL)                         ;FLAGGED BY BIT 7
+        JR NC,EX4
+EX5:
+        LD A,(HL)                       ;LOAD HL WITH THE JUMP
+        INC HL                          ;ADDRESS FROM THE TABLE
+        LD L,(HL)
+        AND 7FH                         ;MASK OFF BIT 7
+        LD H,A
+        POP AF                          ;CLEAN UP THE GABAGE
+        JP (HL)                         ;AND WE GO DO IT
+;-------------------------------------------------------------------------------
+;///////////////////////////////////////////////////////////////////////////////
+;-------------------------------------------------------------------------------
+;COMPUTER SPECIFIC ROUTINES.
+;-------------------------------------------------------------------------------
+SERIAL_INIT:
+
+    ; This routine is for initializing your serial port.
+
+        RET
+;-------------------------------------------------------------------------------
+TX_RDY:
+    ; This routine is checking if the Serial Port is ready to send
+    ; a character.
+    IN A,(0F1h)
+    AND 1
+    JP NZ,TX_RDY
+    RET
+        
+;-------------------------------------------------------------------------------
+RX_RDY:
+
+    ; This routine is for checking if a character is available over
+    ; serial. If a character is available, it returns to the calling
+    ; function with the character in 'A' and the Z-flag reset.
+    ; However, if a character is not available, it returns with the
+    ; Z-flag set.
+
+        RET
+;-------------------------------------------------------------------------------
+;///////////////////////////////////////////////////////////////////////////////
+;-------------------------------------------------------------------------------
+
+LSTROM:                                 ;ALL ABOVE CAN BE ROM
+                    ;HERE DOWN MUST BE RAM
+        ORG  08000H
+        ORG  08700H ; Last 256 bytes of RAM
+VARBGN: DS   55                         ;VARIABLE @(0)
+BUFFER: DS   64                         ;INPUT BUFFER
+BUFEND: DS   1                          ;BUFFER ENDS
+STKLMT: DS   1                          ;TOP LIMIT FOR STACK
+        END

snapshots/jotego_jtcores_pr1100/modules/jtframe/bin/hooks/post-commit

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+if git status -u no | grep ahead; then
+	git push
+fi

snapshots/jotego_jtcores_pr1100/modules/jtframe/bin/hooks/post-merge

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# recompile the jtframe utility after a git pull or merge
+
+if [ ! -z "$JTFRAME" ]; then
+	rm -f $JTFRAME/src/jtframe/jtframe
+	$JTFRAME/bin/jtframe
+fi
+exit 0
+

snapshots/jotego_jtcores_pr1100/modules/jtframe/bin/hooks/pre-commit

@@ -0,0 +1,19 @@
+#!/bin/bash -e
+
+# run go tests
+log=`mktemp`
+for program in jtframe jtutil; do
+	cd $JTFRAME/src/$program
+	echo -n "Go test on $program"
+	if ! go test ./... > $log; then
+		echo " FAIL"
+		cat $log
+		rm -f $log
+		exit 1
+	fi
+	echo " PASS"
+done
+rm -f $log
+
+# check macro usage
+$JTFRAME/bin/unknown-macros.sh

snapshots/jotego_jtcores_pr1100/modules/jtframe/bin/install/jotego_20.04.sh

@@ -0,0 +1,167 @@
+#!/bin/bash
+# Packages needed on a fresh Ubuntu 20,04 installation
+# Sublime-text isn't really needed for compilation but
+# it is the recommended text editor
+
+set -e
+
+# Sublime Text
+wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/sublimehq-archive.gpg > /dev/null
+echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list
+
+sudo apt update
+sudo apt upgrade --yes
+
+sudo apt install --yes --install-suggests apt-transport-https nfs-common
+sudo apt install --yes --install-suggests build-essential git gtkwave figlet xmlstarlet \
+    sublime-text 
+# repository called docker in ubuntu 20.04, docker.io in ubuntu 24.04    
+sudo apt install --yes docker.io
+sudo apt install --yes python-is-python3
+
+# required by iverilog
+sudo apt install --yes flex gperf bison
+
+# libpng12, required by Quartus 17
+wget https://downloads.sourceforge.net/libpng/libpng-1.2.59.tar.gz
+tar -xvzf libpng-1.2.59.tar.gz
+cd libpng-1.2.59
+./configure
+make
+sudo make install
+
+# required by MAME
+sudo apt install --yes libqwt-qt5-dev libsdl2-dev libfontconfig1-dev libsdl2-ttf-dev \
+    libfontconfig-dev libpulse-dev qtbase5-dev qtbase5-dev-tools \
+    qtchooser qt5-qmake
+
+# jtcore and jtupdate
+sudo apt install --yes parallel locate python3-pip fatattr sshpass gawk libxml2-utils
+sudo updatedb
+
+# KiCAD
+sudo add-apt-repository ppa:kicad/kicad-8.0-releases
+sudo apt update
+sudo apt install --yes kicad
+
+# Locale
+sudo apt install --yes locales locales-all
+sudo locale-gen en_US.UTF-8
+
+# open picoblaze assembler needed for assembling the cheat and beta code
+sudo pip install --upgrade opbasm
+
+# as31 to compile 8051/8751 assembler code
+sudo apt install --yes as31
+
+# asm48 to compile MCS-48 assembler code
+cd /tmp
+git clone https://github.com/jotego/asm48.git
+cd asm48
+make
+sudo cp 8039dasm asm48 /usr/local/bin
+
+# macro assembler for many, many CPUs
+cd /tmp
+wget http://john.ccac.rwth-aachen.de:8000/ftp/as/source/c_version/asl-current.tar.gz
+tar xfz asl-current.tar.gz
+cd asl-current
+ln -s Makefile.def-samples/Makefile.def-x86_64-unknown-linux Makefile.def
+make
+sudo cp alink asl p2bin p2hex pbind plist /usr/local/bin
+sudo mkdir -p /usr/local/share/man/man1/
+sudo cp man/* /usr/local/share/man/man1/
+
+# MRA tool to generate .arc files
+cd /tmp
+git clone https://github.com/mist-devel/mra-tools-c.git
+cd mra-tools-c
+make -j
+sudo mv mra /usr/local/bin/mra
+
+# Verilator
+sudo apt install --yes git help2man perl python3 make autoconf g++ flex bison ccache
+sudo apt install --yes libgoogle-perftools-dev numactl perl-doc
+# Ubuntu only (ignore if alrea error)
+sudo apt install --yes libfl2 libfl-dev zlib1g zlib1g-dev 
+
+cd $HOME
+unset VERILATOR_ROOT
+git clone https://github.com/verilator/verilator.git --depth 1 || exit $?
+cd $HOME/verilator
+autoconf
+./configure
+# compile using 80% of available CPUs
+make -j $((`nproc`*4/5))
+export VERILATOR_ROOT=`pwd`
+echo export VERILATOR_ROOT=`pwd` >> $HOME/.bashrc
+
+# Icarus Verilog
+git clone https://github.com/steveicarus/iverilog.git
+cd iverilog
+git checkout v12_0
+sh autoconf.sh
+./configure
+make -j $((`nproc`*4/5))
+sudo make install
+
+# nice to have
+sudo apt install --yes htop flameshot ghex
+
+# git configuration
+git config --global url.ssh://git@github.com/.insteadOf https://github.com/
+git config --global alias.d diff
+git config --global alias.co checkout
+git config --global alias.st status
+git config --global alias.wt worktree
+git config --global alias.p pull
+git config --global alias.b bisect
+git config --global alias.su "submodule update"
+git config --global alias.r "reset --hard"
+# handling of EOL characters
+git config --global core.whitespace cr-at-eol
+git config --global core.autocrlf input
+# aim for a linear history
+git config --global pull.rebase true
+
+# Go
+GONAME=go1.21.3.linux-amd64.tar.gz
+wget https://go.dev/dl/$GONAME
+sudo rm -rf /usr/local/go && sudo tar -C /usr/local -xzf $GONAME
+sudo rm -f $GONAME
+export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin
+echo export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin >> $HOME/.bashrc
+go install github.com/spf13/cobra-cli@latest
+go install golang.org/x/tools/cmd/goimports@latest
+go install golang.org/x/tools/cmd/godoc@latest
+
+# GitHub CLI
+type -p curl >/dev/null || (sudo apt update && sudo apt install curl -y)
+curl -fsSL https://cli.github.com/packages/githubcli-archive-keyring.gpg | sudo dd of=/usr/share/keyrings/githubcli-archive-keyring.gpg \
+&& sudo chmod go+r /usr/share/keyrings/githubcli-archive-keyring.gpg \
+&& echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | sudo tee /etc/apt/sources.list.d/github-cli.list > /dev/null \
+&& sudo apt update \
+&& sudo apt install gh -y
+
+# Set up repositories
+cat<<EOF
+Run these commands after setting the SSH key in GitHub
+
+cd $HOME
+git clone --recurse-submodules git@github.com:jotego/jtcores.git
+mkdir jtmisc
+cd jtmisc
+git clone --depth 1 --shallow-since="$(date --date='-2 weeks' +%F)" git@github.com:jotego/jtbin.git
+git clone git@github.com:jotego/jtbeta.git
+git clone git@github.com:JTFPGA/jtutil.git
+EOF
+
+# USB Blaster
+jtblaster
+
+# audio play and visualization
+sudo apt install mplayer audacity
+
+# Cross-Compiler
+# m68k-linux-gnu-gcc
+sudo apt install gcc-m68k-linux-gnu

snapshots/jotego_jtcores_pr1100/modules/jtframe/bin/install/quartus13_20.04.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# This will set up the libraries required to run Quartus 13 on Ubuntu 20.04
+# Quartus 13.1 should be already installed at /opt/altera/13.1
+# Run with sudo
+
+# Get 
+dpkg --add-architecture i386
+apt update
+apt install make:i386 libxdmcp6:i386 libxau6:i386 libxext6:i386 libxft-dev:i386 \
+	libxft2:i386 libxrender1:i386 libxt6:i386 libfontconfig1-dev:i386 \
+	libxtst6:i386 libx11-6:i386 unixodbc:i386 libzmq3-dev:i386 \
+	libxext6:i386 libxi6:i386
+# Missing ncurses-base:i386	
+
+DIR=`mktemp --directory`
+cd $DIR
+wget http://se.archive.ubuntu.com/ubuntu/pool/main/libp/libpng/libpng12-0_1.2.54-1ubuntu1_i386.deb
+DIR2=`mktemp --directory`
+dpkg -x libpng12-0_1.2.54-1ubuntu1_i386.deb $DIR2
+cp $DIR2/lib/i386-linux-gnu/* /usr/lib32
+
+# Create a script to run quartus13
+cat > /usr/bin/q13 <<EOF
+#!/bin/bash
+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:.
+PATH=$PATH:/opt/altera/13.1/quartus/bin:/opt/altera/13.1/quartus/linux
+export PATH
+quartus
+EOF
+chmod +x /usr/bin/q13

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/T80.yaml

@@ -0,0 +1,14 @@
+jtframe:
+  - from: cpu/t80
+    unless: [ VERILATOR, IVERILOG ]
+    get:
+      - T80pa.vhd
+      - T80s.vhd
+      - T80_Reg.vhd
+      - T80_MCode.vhd
+      - T80_ALU.vhd
+      - T80.vhd
+  - from: cpu/t80
+    when: [ VERILATOR, IVERILOG ]
+    get:
+      - T80s.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/j68.yaml

@@ -0,0 +1,14 @@
+jtframe:
+  - from: cpu/j68
+    get:
+      - cpu_j68.v
+      - j68_addsub_32.v
+      - j68_alu.v
+      - j68_decode_rom.v
+      - j68_decode.v
+      - j68_dpram_2048x20.v
+      - j68_flags.v
+      - j68_loop.v
+      - j68_mem_io.v
+      - j68_test.v
+      - jtframe_j68.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_63701v.yaml

@@ -0,0 +1,10 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_6801mcu.v
+  - from: ram
+    get:
+      - jtframe_ram.v
+jt680x:
+  - get:
+    - jt6301.yaml

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_63701y.yaml

@@ -0,0 +1,10 @@
+jtframe:
+  - from: cpu
+    get:
+      - jt63701y.v
+  - from: ram
+    get:
+      - jtframe_ram.v
+jt680x:
+  - get:
+    - jt6301.yaml

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_6801mcu.yaml

@@ -0,0 +1,10 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_6801mcu.v
+  - from: ram
+    get:
+      - jtframe_ram.v
+jt680x:
+  - get:
+    - jt6801.yaml

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_6805mcu.yaml

@@ -0,0 +1,10 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_6805mcu.v
+  - from: ram
+    get:
+      - jtframe_ram.v
+jt680x:
+  - get:
+    - jt6805.yaml

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_6809.yaml

@@ -0,0 +1,9 @@
+jtframe:
+  - from: cpu
+    get:
+      - mc6809i.v
+      - jtframe_sys6809.v
+      - jtframe_z80wait.v
+  - from: ram
+    get:
+      - jtframe_dual_ram.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_8751.yaml

@@ -0,0 +1,8 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_8751mcu.v
+      - mc8051.yaml
+  - from: ram
+    get:
+      - jtframe_ram_rst.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_m68k.yaml

@@ -0,0 +1,10 @@
+jtframe:
+  - from: cpu
+    get:
+      - j68.yaml
+      - jtframe_m68k.v
+      - jtframe_68kdma.v
+      - jtframe_68kdtack.v
+      - jtframe_68kdtack_cen.v
+      - jtframe_68kramcs.v
+fx68k:

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_mos6502.yaml

@@ -0,0 +1,5 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_mos6502.v
+      - chip_6502.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/jtframe_z80.yaml

@@ -0,0 +1,9 @@
+jtframe:
+  - from: cpu
+    get:
+      - jtframe_z80.v
+      - jtframe_z80wait.v
+      - T80.yaml
+  - from: ram
+    get:
+      - jtframe_dual_nvram.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/mc8051.yaml

@@ -0,0 +1,59 @@
+jtframe:
+  - unless: [VERILATOR, IVERILOG]
+    from: cpu
+    get:
+      - jtframe_8751mcu.v
+  - unless: [VERILATOR, IVERILOG]
+    from: cpu/8051
+    get:
+      - mc8051_p.vhd
+      - control_fsm_.vhd
+      - control_fsm_rtl.vhd
+      - control_fsm_rtl_cfg.vhd
+      - control_mem_.vhd
+      - control_mem_rtl.vhd
+      - control_mem_rtl_cfg.vhd
+      - alumux_.vhd
+      - alumux_rtl.vhd
+      - alumux_rtl_cfg.vhd
+      - alucore_.vhd
+      - alucore_rtl.vhd
+      - alucore_rtl_cfg.vhd
+      - addsub_cy_.vhd
+      - addsub_cy_rtl.vhd
+      - addsub_cy_rtl_cfg.vhd
+      - addsub_ovcy_.vhd
+      - addsub_ovcy_rtl.vhd
+      - addsub_ovcy_rtl_cfg.vhd
+      - addsub_core_.vhd
+      - addsub_core_struc.vhd
+      - addsub_core_struc_cfg.vhd
+      - comb_divider_.vhd
+      - comb_divider_rtl.vhd
+      - comb_divider_rtl_cfg.vhd
+      - comb_mltplr_.vhd
+      - comb_mltplr_rtl.vhd
+      - comb_mltplr_rtl_cfg.vhd
+      - dcml_adjust_.vhd
+      - dcml_adjust_rtl.vhd
+      - dcml_adjust_rtl_cfg.vhd
+      - mc8051_siu_.vhd
+      - mc8051_siu_rtl.vhd
+      - mc8051_siu_rtl_cfg.vhd
+      - mc8051_tmrctr_.vhd
+      - mc8051_tmrctr_rtl.vhd
+      - mc8051_tmrctr_rtl_cfg.vhd
+      - mc8051_alu_.vhd
+      - mc8051_alu_struc.vhd
+      - mc8051_alu_struc_cfg.vhd
+      - mc8051_control_.vhd
+      - mc8051_control_struc.vhd
+      - mc8051_control_struc_cfg.vhd
+      - mc8051_core_.vhd
+      - mc8051_core_struc.vhd
+  # Verilog-only version, good for verilog simulators
+  # but compiles slowly
+  - when: [VERILATOR, IVERILOG]
+    from: cpu
+    get:
+      - mc8051.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/t48.yaml

@@ -0,0 +1,46 @@
+# This is the right order for Modelsim to parse the files
+jtframe:
+  - from: cpu/t48
+    unless: [VERILATOR]
+    get:
+      - t48_pack-p.vhd
+      - t48_tb_pack-p.vhd
+      - alu_pack-p.vhd
+      - cond_branch_pack-p.vhd
+      - decoder_pack-p.vhd
+      - dmem_ctrl_pack-p.vhd
+      - pmem_ctrl_pack-p.vhd
+      - t48_comp_pack-p.vhd
+      - t48_core_comp_pack-p.vhd
+      - alu.vhd
+      - alu-c.vhd
+      - bus_mux.vhd
+      - bus_mux-c.vhd
+      - clock_ctrl.vhd
+      - clock_ctrl-c.vhd
+      - cond_branch.vhd
+      - cond_branch-c.vhd
+      - db_bus.vhd
+      - db_bus-c.vhd
+      - int.vhd
+      - int-c.vhd
+      - timer.vhd
+      - timer-c.vhd
+      - decoder.vhd
+      - decoder-c.vhd
+      - dmem_ctrl.vhd
+      - dmem_ctrl-c.vhd
+      - p1.vhd
+      - p1-c.vhd
+      - p2.vhd
+      - p2-c.vhd
+      - pmem_ctrl.vhd
+      - pmem_ctrl-c.vhd
+      - psw.vhd
+      - psw-c.vhd
+      - t48_core.vhd
+      - t48_core-c.vhd
+  - from: cpu/t48
+    when: [VERILATOR]
+    get:
+      - t48_core.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/t65.yaml

@@ -0,0 +1,12 @@
+jtframe:
+  - from: cpu/t65
+    unless: [VERILATOR]
+    get:
+      - T65.vhd
+      - T65_Pack.vhd
+      - T65_ALU.vhd
+      - T65_MCode.vhd
+  - from: cpu/t65
+    when: [VERILATOR]
+    get:
+      - t65.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/t8243.yaml

@@ -0,0 +1,8 @@
+jtframe:
+  - from: cpu/t8243
+    get:
+    - t8243_sync_notri-c.vhd
+    - t8243_sync_notri.vhd
+    - t8243_comp_pack-p.vhd
+    - t8243_core-c.vhd
+    - t8243_core.vhd

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/cpu/upi41.yaml

@@ -0,0 +1,49 @@
+jtframe:
+  - from: cpu/t48
+    unless: [VERILATOR]
+    get:
+      - t48_pack-p.vhd
+      - alu_pack-p.vhd
+      - cond_branch_pack-p.vhd
+      - decoder_pack-p.vhd
+      - pmem_ctrl_pack-p.vhd
+      - dmem_ctrl_pack-p.vhd
+      - t48_comp_pack-p.vhd
+      - t48_tb_pack-p.vhd
+      - t48_core_comp_pack-p.vhd
+      - bus_mux.vhd
+      - bus_mux-c.vhd
+      - alu.vhd
+      - alu-c.vhd
+      - clock_ctrl.vhd
+      - clock_ctrl-c.vhd
+      - db_bus.vhd
+      - db_bus-c.vhd
+      - int.vhd
+      - int-c.vhd
+      - upi41_db_bus.vhd
+      - upi41_db_bus-c.vhd
+      - cond_branch.vhd
+      - cond_branch-c.vhd
+      - decoder.vhd
+      - decoder-c.vhd
+      - dmem_ctrl.vhd
+      - dmem_ctrl-c.vhd
+      - p1.vhd
+      - p1-c.vhd
+      - p2.vhd
+      - p2-c.vhd
+      - pmem_ctrl.vhd
+      - pmem_ctrl-c.vhd
+      - psw.vhd
+      - psw-c.vhd
+      - timer.vhd
+      - timer-c.vhd
+      - t48_core.vhd
+      - t48_core-c.vhd
+      - upi41_core.vhd
+      - upi41_core-c.vhd
+  - from: cpu/t48
+    when: [VERILATOR]
+    get:
+      - upi41_core.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/sdram/jtframe_sdram64.yaml

@@ -0,0 +1,31 @@
+jtframe:
+  - from: sdram
+    get:
+      - jtframe_sdram64.v
+      - jtframe_sdram64_bank.v
+      - jtframe_sdram64_init.v
+      - jtframe_sdram64_rfsh.v
+      - jtframe_sdram64_latch.v
+      - jtframe_ramslot_ctrl.v
+      - jtframe_ram1_1slot.v
+      - jtframe_ram1_2slots.v
+      - jtframe_ram1_3slots.v
+      - jtframe_ram1_4slots.v
+      - jtframe_ram1_5slots.v
+      - jtframe_ram2_4slots.v
+      - jtframe_ram2_5slots.v
+      - jtframe_ram2_6slots.v
+      - jtframe_rom_1slot.v
+      - jtframe_rom_2slots.v
+      - jtframe_rom_3slots.v
+      - jtframe_rom_4slots.v
+      - jtframe_rom_5slots.v
+      - jtframe_rom_6slots.v
+      - jtframe_rom_7slots.v
+      - jtframe_romrq.v
+      - jtframe_romrq_bcache.v
+      - jtframe_romrq_xscache.v
+      - jtframe_ucache.v
+      - jtframe_rom.v
+      - jtframe_ram_rq.v
+      - jtframe_rom_sync.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/sdram/jtframe_sdram_bank.yaml

@@ -0,0 +1,23 @@
+jtframe:
+  - from: sdram
+    get:
+      - jtframe_sdram_bank.v
+      - jtframe_sdram_bank_core.v
+      - jtframe_sdram_bank_mux.v
+      - jtframe_ram1_2slots.v
+      - jtframe_ram1_3slots.v
+      - jtframe_ram1_4slots.v
+      - jtframe_ram1_5slots.v
+      - jtframe_ram2_4slots.v
+      - jtframe_ram2_5slots.v
+      - jtframe_ram2_6slots.v
+      - jtframe_rom_1slot.v
+      - jtframe_rom_2slots.v
+      - jtframe_rom_3slots.v
+      - jtframe_rom_4slots.v
+      - jtframe_rom_5slots.v
+      - jtframe_rom_6slots.v
+      - jtframe_romrq.v
+      - jtframe_rom.v
+      - jtframe_ram_rq.v
+      - jtframe_rom_sync.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/sound/jtframe_jt49_filters.yaml

@@ -0,0 +1,6 @@
+jtframe:
+  - from: sound
+    get:
+    - jtframe_jt49_filters.v
+    - jtframe_fir.v
+    - jtframe_dcrm.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/video/jtframe_obj.yaml

@@ -0,0 +1,11 @@
+jtframe:
+  - from: video
+    get:
+      - jtframe_draw.v
+      - jtframe_objscan.v
+      - jtframe_objdraw.v
+      - jtframe_objdraw_trunc.v
+      - jtframe_objdraw_gate.v
+  - from: ram
+    get:
+      - jtframe_obj_buffer.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/cfg/video/jtframe_scroll.yaml

@@ -0,0 +1,6 @@
+jtframe:
+  - from: video/tilemap
+    get:
+      - jtframe_scroll.v
+      - jtframe_scroll_offset.v
+      - jtframe_tilemap.v

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/build-dockers.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+docker image build --file jtcore-base.df --tag jotego/jtcore-base .
+docker image build --file jtcore13.df --tag jotego/jtcore13 /opt/altera
+docker image build --file jtcore17.df --tag jotego/jtcore17 /opt/intelFPGA_lite
+docker image build --file jtcore20.df --tag jotego/jtcore20 /opt/intelFPGA_lite
+docker image build --file linter.df --tag jotego/linter .
+
+# Push the images to dockerhub
+docker login
+docker push jotego/jtcore-base:latest
+docker push jotego/jtcore13:latest
+docker push jotego/jtcore17:latest
+docker push jotego/jtcore20:latest
+docker push jotego/linter:latest

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/docker-jtcore.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+
+git clone --shallow-submodules  --recurse-submodules git/jtcores.git
+cd jtcores
+COMMIT=$1
+git checkout $COMMIT
+shift
+
+. modules/jtframe/bin/setprj.sh
+jtframe
+cd $JTROOT
+
+jtcore $*
+mkdir -p /release/$COMMIT
+rsync release /release/$COMMIT

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/jtcore-base.df

@@ -0,0 +1,43 @@
+FROM ubuntu:20.04
+LABEL maintainer=jotego@gmail.com
+
+RUN apt update
+RUN ln -fs /usr/share/zoneinfo/Europe/Madrid /etc/localtime
+RUN apt install -yq git curl gawk
+RUN apt install -yq ca-certificates libgnutls30
+RUN apt install -yq ftp figlet xmlstarlet flex
+RUN apt install -yq rsync
+
+# Python
+RUN apt install -yq python python3-pip && pip install pypng
+
+# Go
+RUN GONAME=go1.21.3.linux-amd64.tar.gz; curl -LO https://go.dev/dl/$GONAME && tar -C /usr/local -xzf $GONAME && rm -f $GONAME
+ENV PATH="$PATH:/usr/local/go/bin"
+
+# iverilog compilation
+RUN apt install -yq --install-suggests build-essential git zlib1g-dev
+RUN apt install -yq flex gperf bison
+
+# Assembler tools
+RUN pip install --upgrade opbasm
+RUN apt install -yq as31
+RUN cd /tmp; git clone https://github.com/jotego/asl.git; cd asl; make -j; cp alink asl p2bin p2hex pbind plist /usr/local/bin
+
+# JT core environment
+RUN mkdir /jtbin; echo export JTBIN=/jtbin >> $HOME/.bashrc
+
+# Locales
+RUN apt update
+RUN apt install locales locales-all
+RUN locale-gen en_US.UTF-8
+RUN echo LC_ALL=en_US.UTF-8 >> /etc/environment
+RUN echo LANG=en_US.UTF-8 >> /etc/environment
+
+# Needed by Quartus 17
+RUN apt-get install -y libglib2.0-0
+
+# Needed by xjtcore.sh
+RUN apt install -y xxd
+
+ENTRYPOINT ["bash"]

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/jtcore13.df

@@ -0,0 +1,15 @@
+FROM jotego/jtcore-base
+LABEL maintainer=jotego@gmail.com
+
+# 32-bit support
+RUN dpkg --add-architecture i386 && apt update
+
+# 32-bit libraries
+RUN ln -fs /usr/share/zoneinfo/Europe/Madrid /etc/localtime && apt-get install -y tzdata && dpkg-reconfigure --frontend noninteractive tzdata
+RUN apt install make:i386 libxdmcp6:i386 libxau6:i386 libxext6:i386 libxft-dev:i386 libxft2:i386 libxrender1:i386 libxt6:i386 libfontconfig1-dev:i386 libxtst6:i386 libx11-6:i386 unixodbc:i386 libzmq3-dev:i386 libxext6:i386 libxi6:i386 -y
+# missing ncurses-base:i386 -y
+
+COPY 13.1 /opt/altera/13.1
+ENV PATH $PATH:/opt/altera/13.1/quartus/bin
+
+ENTRYPOINT ["bash"]

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/jtcore17.df

@@ -0,0 +1,7 @@
+FROM jotego/jtcore-base
+LABEL maintainer=jotego@gmail.com
+
+COPY 17.1 /opt/intelFPGA_lite/17.1
+ENV PATH $PATH:/opt/intelFPGA_lite/17.1/quartus/bin
+
+ENTRYPOINT ["bash"]

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/jtcore20.df

@@ -0,0 +1,14 @@
+FROM jotego/jtcore-base
+LABEL maintainer=jotego@gmail.com
+
+RUN mkdir -p /opt/intelFPGA_lite/20.1
+COPY 20.1/devdata   /opt/intelFPGA_lite/20.1/devdata
+COPY 20.1/ip        /opt/intelFPGA_lite/20.1/ip
+COPY 20.1/licenses  /opt/intelFPGA_lite/20.1/licenses
+COPY 20.1/logs      /opt/intelFPGA_lite/20.1/logs
+COPY 20.1/quartus   /opt/intelFPGA_lite/20.1/quartus
+COPY 20.1/uninstall /opt/intelFPGA_lite/20.1/uninstall
+ENV PATH $PATH:/opt/intelFPGA_lite/20.1/quartus/bin
+
+
+ENTRYPOINT ["bash"]

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/linter.df

@@ -0,0 +1,22 @@
+FROM jotego/jtcore-base
+LABEL maintainer=jotego@gmail.com
+
+RUN apt install -y autoconf
+
+# Verilator
+RUN cd /opt; git clone https://github.com/verilator/verilator.git --depth 1
+RUN cd /opt/verilator; autoconf; ./configure
+RUN cd /opt/verilator; make -j $((`nproc`*4/5)); echo Done
+RUN find /opt/verilator -name "*.o" -delete
+RUN apt install -y gettext
+
+ENV PATH=$PATH:/opt/verilator/bin:/usr/local/go/bin
+ENV VERILATOR_ROOT=/opt/verilator
+
+# Icarus Verilog
+RUN apt install -y libbz2-dev
+RUN git clone https://github.com/steveicarus/iverilog.git --branch v12_0 --single-branch
+RUN cd iverilog && bash autoconf.sh && ./configure && make -j $((`nproc`*4/5)) && make install
+RUN cd ..; rm -rf iverilog
+
+ENTRYPOINT ["bash"]

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/xjtcore.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+# usage:
+# xjtcore <corename> [--debug] target-names...
+set -e
+
+git config --global --add safe.directory /jtcores
+cd /jtcores
+export JTROOT=$(pwd)
+export JTFRAME=$JTROOT/modules/jtframe
+
+source $JTFRAME/bin/setprj.sh > /dev/null
+export PATH=$PATH:/usr/local/go/bin
+
+# 1st argument is the core name
+CORENAME=$1
+shift
+# next argument can select debug mode, which is on by default
+NODBG=--nodbg
+if [ $1 = --debug ]; then
+    NODBG=
+    shift
+fi
+
+if [ -z "$BETAKEY" ]; then
+    BETAKEY=`printf "%04X%04X" $RANDOM $RANDOM`
+    echo "WARNING: remote compilation with no beta key. Assigning random one"
+fi
+
+export JTUTIL=/jtutil
+mkdir $JTUTIL
+printf "%08x" 0x$BETAKEY | xxd -r -p > $JTUTIL/beta.bin
+ls -l $JTUTIL/beta.bin
+
+
+if [ -e $CORES/$CORENAME/cfg/macros.def ]; then
+    # Beta key is enabled for cores listed in beta.yaml
+    for TARGET in $*; do
+        if jtframe cfgstr $CORENAME --target=$TARGET --output bash | grep JTFRAME_SKIP; then
+            echo "Skipping $CORENAME for $TARGET because of JTFRAME_SKIP"
+            continue
+        fi
+        if [ $TARGET != pocket ]; then SKIPPOCKET=--skipPocket; else unset SKIPPOCKET; fi
+        jtframe mra $NODBG --skipROM $SKIPPOCKET $CORENAME
+        echo "Compiling for $TARGET"
+        jtseed 6 $CORENAME -$TARGET $NODBG --nolinter
+        # recover hard disk space
+        rm -rf $CORES/$CORENAME/$TARGET
+    done
+fi

snapshots/jotego_jtcores_pr1100/modules/jtframe/devops/xsimunit.sh

@@ -0,0 +1,10 @@
+#!/bin/bash -e
+# prepares the environment before running simunit
+
+git config --global --add safe.directory /jtcores
+cd /jtcores
+export JTROOT=$(pwd)
+export JTFRAME=$JTROOT/modules/jtframe
+
+source $JTFRAME/bin/setprj.sh > /dev/null
+simunit.sh --run $*

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/audio.md

@@ -0,0 +1,30 @@
+# Audio Processing (Filters!)
+
+There are some facilities to help with the upsampling needed for the DACs. Some modules need a hex file containing the value of the coefficients to be copied into the MiST(er) folder for compilation. The hex files are available in hdl/sound folder.
+
+## jtframe_fir
+
+The module **jtframe_fir** is designed to operate on a stereo signal input to apply a FIR filter of up to 127 coefficients. It takes one BRAM block. As it needs about 256 clocks per sample, the input sampling frequency must be lower than clk/256.
+
+## jtframe_dcrm
+
+IIR filter to remove the DC value of a signal.
+
+## jtframe_jt49_filters
+
+This covers the usual situation of having two JT49 instances in a core. This module will add the two outputs, remove DC and filter out frequencies about 14kHz (for a JT49 clock of 1.5MHz). There is a qip file for this module.
+
+# Audio Parameters in mem.yaml
+
+Schematic information can be translated to parameters in mem.yaml to automatically compute low-pass filters and gain balance
+
+![Filter example](images/rsum1.png)
+
+```
+rsum: 1k+1k+1.2k = 3.2k
+rc: [ r: 1k, c: 33n ]
+``
+
+If the filter is of second order without an amplifier separating each filter pole, an equivalent 2-stage single-pole filter must be calculated. See the image below.
+
+![second-order filter in a single stage](images/rc-equivalent.png)

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat-tutorial.md

@@ -0,0 +1,242 @@
+# Cheat Development Tutorial
+
+## Introduction
+
+Arcade cheats are made manipulating either the game ROM or the CPU RAM. The
+ROM can be modified statically, with `<patch>` in the MRA file. However, the
+game RAM can only be modified when the game is actually running, so you need
+a way to access it.
+
+JTFRAME cheat engine provides a way of accessing all the SDRAM information
+contained on bank 0. Bank 0 is used as the R/W bank for arcade games in JT
+cores. Other SDRAM banks are used as read-only memory. Some JT arcade cores
+take advantage of this feature to implement the game RAM and even VRAM directly
+on the SDRAM. As of June 2021, these cores are:
+
+* CPS series
+* Street Fighter 1
+* System 16
+* The Speed Rumbler
+
+Older cores may be updated to move the RAM to the SDRAM. Even if the SDRAM
+only contains the ROM, the cheat engine can still be used. It just cannot
+modify RAM contents.
+
+The cheat engine is built around a small processor called the PicoBlaze. You
+will need to write a small piece of code that modifies the game data as needed.
+
+There is plenty of information about cheat code on the internet, including a
+wonderful tutorial on how to develop cheat codes [here](http://cheat.retrogames.com/download/holycheat!.zip).
+
+The cheat information is added to the core by enabling it on the MRA file, and
+then adding a new PicoBlaze instruction ROM to the MiSTer's cheat.zip. Do not
+confuse MiSTer's cheat.zip file with MAME's cheat.zip. They are named the same
+but the contents have nothing to do.
+
+This tutorial will show how to modify two games, one for CPS1 and one for CPS2.
+
+You will need the MAME file cheat.zip. Uncompress it to a folder.
+
+## Eco Fighters (CPS2)
+
+Look for the file ecofghtr.xml in your uncompressed cheat.zip. You will see a
+list of XML elements like this one:
+
+```
+  <cheat desc="Infinite Credits">
+    <script state="run">
+      <action>maincpu.pb@FF02E8=09</action>
+    </script>
+  </cheat>
+```
+
+This means that once per frame, the CPU RAM mapped at FF02E8 must be set to 9.
+
+The PicoBlaze has the vertical blanking mapped to bit 5 of port $80. In order to
+check when blanking has occur there is a small piece of code that you can just
+reuse:
+
+```
+    load sa,0   ; SA = frame counter, modulo 60
+    load sb,0
+BEGIN:
+    output s0,0x40
+
+    ; Detect blanking
+    input s0,0x80
+    and   s0,0x20;   test for blanking
+    jump z,inblank
+    jump notblank
+inblank:
+    fetch s1,0
+    test s1,0x20
+    jump z,notblank
+    store s0,0  ; stores last LVBL
+    call ISR ; do blank procedure
+    jump BEGIN
+notblank:
+    store s0,0
+    jump BEGIN
+```
+
+The important thing is that register **SA** contains the frame counter, from
+0 to 59. If you want to do something once per second, just compare SA to any
+number in the 0 to 59 range. SA will pass through that number exactly once per
+second.
+
+This code will clean the watchdog too. The watchdog is a hardware counter that
+will reset this CPU after a certain time. This is a safety measure. The code
+`output s0,0x40` clears the count, so no reset occurs.
+
+When a blanking event happens, the code will jump to **ISR** (Interrupt Service
+Response).
+
+The ISR code  starts by checking the cheat flags, which the user has modified
+via the MiSTer OSD menu.
+
+```
+ISR:
+    input sf,0x10
+    test sf,0xff
+    jump z,.nothing
+
+    compare sa,0
+    jump nz,PARSE_FLAGS
+    ; invert LED signal
+    add sb,1
+    jump PARSE_FLAGS
+.nothing:
+    load sb,0      ; turn off LED
+    jump CLOSE_FRAME
+```
+
+The flags are read from port $10. If no cheats are enabled (all flags zero),
+then the LED is turned off. The LED status is held in register **SB**. If
+there are enabled cheats, then the LED will be toggled `add sb,1` and the
+code will jump to PARSE_FLAGS.
+
+Parsing the flags consists on checking the relevant bit -as specified in the
+MRA file- and then performing the relevant action, which in general will be
+a single write to the game RAM.
+
+```
+PARSE_FLAGS:
+    input sf,0x10
+    test  sf,1      ; bit 0
+    jump Z,TEST_FLAG1
+    ; Infinite Credits
+    ; FF02E8=09 -> (02E8/2+30'0000) = 300174
+    load  s0,0x74
+    load  s1,0x01
+    load  s2,0x30
+    load  s3,0
+    load  s4,9
+    load  s5,1
+    call  WRITE_SDRAM
+TEST_FLAG1:
+```
+
+This code checks bit 0, and if set it will write the value 9 to the RAM
+address FF02E8. For convenience, there is a function called **WRITE_SDRAM** which
+will write the contents of registers **S4-S3** to the memory address set by
+registers **S2-S1-S0**. As the memory is made of 16-bit words, the byte that is
+being written is set by **S5**, 1 means that the high byte (register **S4**) is
+accessed, 2 means the low byte (**S3**) and 0 means both.
+
+Now, in order to convert the system address (FF02E8) to the SDRAM address, you
+need to know where the RAM is stored in the SDRAM. This information is typically
+in the jtcps1_sdram file of the game, for instance in [CPS.](https://github.com/jotego/jtcps1/blob/d05f18f8981c55ada00e1b3365848cf9ba4486bb/cores/cps1/hdl/jtcps1_sdram.v#L150).
+
+For CPS cores the work RAM is in $30'0000. So this offset must be added to the
+game address. But another point is that the top 8 bits of the address are not
+part of the data address, but only serve to indicate that the work RAM portion
+of the memory mapped is active. This can be seen in the MAME driver or in the
+core decoder logic and is different for each system. But for all CPS cores, the
+same logic applies. Another caveat is that for 16-bit CPUs, the address must be
+divided by 2. So finally the address **FF02E8** becomes **30'0174**.
+
+The code loads that address and the 9 value. Note that in 16-bit systems, the
+byte location may be confusing to because of endianness. For M68000 games, just
+follow this example.
+
+Once this code is executed, the next flag will be checked, and eventually the
+frame processing will get closed with:
+
+```
+CLOSE_FRAME:
+    output sb,6     ; LED
+    ; Frame counter
+    add sa,1
+    compare sa,59'd
+    jump nz,.else
+    load sa,0
+.else:
+    return
+```
+
+The closing frame just updates the LED and the frame counter. You can see the
+full code of this example [here](cheat/ecofghtr.s).
+
+Now you need to assemble the new file and add it to MiSTer's cheat.zip. The
+file [cheatzip](cheat/cheatzip) shows how to do it. Here are the steps as
+individual linux commands:
+
+```
+> opbasm -6 -x -m 1024 ecofghtr.s
+> pico2hex ecofghtr.hex
+> zip cheat.zip ecofghtr.bin
+> sshpass -p 1 scp cheat.zip root@MiSTer.home:/media/fat/games/mame
+```
+
+First, the file is assembled using [opbasm](https://github.com/kevinpt/opbasm).
+Then the output is converted to a binary format that MiSTer can handle using
+pico2hex (available in JTBIN's bin folder). This utility basically converts
+a 18-bit hex stream to a 8-bit one. Finally the binary file is added to
+cheat.zip and transferred to MiSTer.
+
+The MRA needs to load this binary to the ROM position 16:
+
+```
+    <rom index="16" zip="cheat.zip" md5="None">
+        <part name="ecofghtr.bin"/>
+    </rom>
+```
+
+And of course, it must include descriptions of each cheat:
+
+```
+    <cheats>
+        <dip name="Infinite Credits" bits="0" ids="No,Yes"/>
+        <dip name="P1 Infinite Lives" bits="1" ids="No,Yes"/>
+        <dip name="P1 Invincibility" bits="2" ids="No,Yes"/>
+    </cheats>
+```
+
+The full MRA example is [here](https://github.com/jotego/jtcps1/blob/master/rom/mra/Eco%20Fighters%20(cheat).mra)
+
+And that covers the basics, it may look like many concepts but if you start
+with the example you will find that it is easy to modify it to add more cheats
+or target other games.
+
+Check the example for Ghouls'n Ghosts too:
+
+* [Assembler File](cheat/ghouls.s)
+* [MRA](https://github.com/jotego/jtcps1/blob/master/rom/mra/Ghouls'n%20Ghosts%20(cheat).mra)
+
+Finally, sometimes you need to read data from the SDRAM, you can find sample
+code for reading in [sf2hf.s](cheat/sf2hf.s).
+
+```
+    ; Read FF8AC2 => 304561 and check that its zero
+    load  s0,0x61
+    load  s1,0x45
+    load  s2,0x30
+    call  READ_SDRAM
+    compare s7,0
+    jump nz,char_select
+```
+
+This code reads the data in game address FF8AC2. The data is returned in
+registers s7 and s6. Because of the M68000 endianness, the lower byte is
+written in s7, and the upper in s6. Then you can perform a check on the
+value and jump accordingly.

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat.md

@@ -0,0 +1,167 @@
+# Cheat Engine
+
+The cheat engine consists of a Picoblaze compatible CPU that has full access
+to SDRAM bank zero. This tiny CPU can be used to implement the MAME cheats,
+as well as it can be used to perform other functions, like high-score
+extraction and help in debugging the system during development.
+
+![Cheat Subsystem](cheat.png)
+
+The cheat engine comes with a cost in FPGA space usage and synthesis time, so
+it is disabled by default. It is enabled by defining the macro **JTFRAME_CHEAT**.
+
+See the [cheat tutorial](cheat-tutorial.md) for learning how to add new cheats.
+
+## Compilation Requirements
+
+Note that if **JTFRAME_CHEAT** is set, you will need a cheat.hex file in the compilation folder. As with other hex files, normally you place it in the mist folder and _jtcore_ will link it from there when you compile other targets. It is also possible to place it in the _hdl_ folder.
+
+The _cheat.hex_ contains the 18-bit hex words for the firmware, and can be generated as described in the [cheat tutorial](cheat-tutorial.md).
+
+## MRA File
+
+Cheats are added to the MRA file like this:
+
+```
+<cheats>
+    <dip name="Infinite Credits" bits="0" ids="No,Yes"/>
+    <dip name="P1 Infinite Lives" bits="1" ids="No,Yes"/>
+    <dip name="P1 Invincibility" bits="2" ids="No,Yes"/>
+</cheats>
+```
+
+It basically follows the same syntax as the DIP switches, but the top element
+is called `<cheats>`. There are a maximum of 32 bits available. The MiSTer
+firmware must be older than 4th June 2021 to support it.
+
+The MRA also needs to load the PizoBlaze firmware in ROM position 16:
+
+```
+<rom index="16" zip="cheat.zip" md5="None">
+    <part name="mycheat.bin"/>
+</rom>
+```
+
+## Port Map
+
+Port (hex) | I/O    |  Usage
+-----------|--------|-------------------------
+2,1,0      | I/O    | SDRAM address (24 bits)
+4,3        | O      | data to SDRAM
+5          | O      | SDRAM write data mask, only bits 1,0. Active low
+7,6        | I      | data read from SDRAM
+6          | O      | bit 0 = board LED
+8-B        | I/O    | VRAM control (see below)
+C-F        | I/O    | Game module communication (see below)
+10-13      | I      | cheat flags (meaning defined in MRA file)
+14-17      | I      | board status 32-bit word (17=MSB)
+18         | I      | 1P joystick
+1A         | I      | 1P joystick left  analogue stick X
+1B         | I      | 1P joystick left  analogue stick Y
+1C         | I      | 1P joystick right analogue stick X
+1D         | I      | 1P joystick right analogue stick Y
+20-2C      | I      | Time information (see below)
+48         | I      | 2P joystick
+4A         | I      | 2P joystick left  analogue stick X
+4B         | I      | 2P joystick left  analogue stick Y
+4C         | I      | 2P joystick right analogue stick X
+4D         | I      | 2P joystick right analogue stick Y
+34         | I/O    | UART Rx/Tx data
+35         | I      | UART status {rx_error,2'b0,tx_busy,rx_rdy}
+40         | O      | Resets the watchdog
+80         | O      | Starts SDRAM read
+80         | I      | Reads peripheral status (bits 7:6)
+C0         | O      | Starts SDRAM write
+
+Time information
+
+Port (hex) | I/O    |  Usage
+-----------|--------|-------------------------
+20-23      | I      | Bootup timestamp
+24-27      | I      | build timestamp
+28-2B      | I      | current timestamp
+2C         | I      | frame counter
+
+Uses the credits VRAM to display information (JTFRAME_CREDITS required):
+
+Port (hex) | I/O    |  Usage
+-----------|--------|-------------------------
+8          | O      | VRAM column address (bits 4:0)
+9          | O      | VRAM row address (bits 4:0)
+A          | I/O    | VRAM reads or writes
+B          | O      | VRAM control, see below
+
+VRAM control port (B)
+
+Bit   |   Usage
+------|----------
+0     | Sets credits OSD to be controlled by the picoblaze
+1     | dims the top half of the screen
+2     | dims the bottom half of the screen
+
+The screen is dimmed only if bit 0 is set too
+
+Communication with game module
+
+Port (hex) | I/O    |  Usage
+-----------|--------|-------------------------
+C          | O      | Status address (JTFRAME_STATUS required)
+D          | I      | Status data from game
+F          | I      | Debug bus
+
+The peripheral status bits are read from port 0x80:
+
+Bit   |  Meaning
+------|--------------
+7     | Bus ownership, when high the Picoblaze is controlling the SDRAM
+6     | high if a PicoBlaze started SDRAM transaction has not finished
+5     | Low during vertical blanking
+4:2   | Reserved
+1     | Beta period has expired
+0     | System is locked
+
+The following constant can be used in the assembler code for the ports:
+
+```
+constant LED,      6
+constant VRAM_COL, 8
+constant VRAM_ROW, 9
+constant VRAM_DATA,A
+constant VRAM_CTRL,B
+constant ST_ADDR,  C
+constant ST_DATA,  D
+constant DEBUG_BUS,F
+constant FLAGS,    10
+constant BOARD_ST0,14
+constant BOARD_ST1,15
+constant BOARD_ST2,16
+constant BOARD_ST3,17
+constant JOY1,     18
+constant ANA1RX,   1C
+constant ANA1RY,   1D
+constant FRAMECNT, 2c
+constant KEYS,     30
+constant UART_DATA,34
+constant UART_ST,  35
+constant WATCHDOG, 40
+constant JOY2,     48
+constant ANA2RX,   4C
+constant ANA2RY,   4D
+constant STATUS,   80
+```
+
+## Future Features
+
+The following features will be added to the cheat subsystem
+
+* Keyboard and joystick manipulation, both input and output
+* Interrupt at vertical blank -currently a bug in the softcore prevents it
+* Data dump via high-score/NVRAM interfaces
+
+## Resources
+
+* [PicoBlaze User Guide](https://www.xilinx.com/support/documentation/ip_documentation/ug129.pdf)
+* [Open PicoBlaze Assembler](https://github.com/kevinpt/opbasm)
+* [Macro support for opbasm](http://kevinpt.github.io/opbasm/rst/m4.html)
+* [PicoBlaze VHDL generic version](https://github.com/krabo0om/pauloBlaze)
+* [Holy Cheat! Guide](http://cheat.retrogames.com/download/holycheat!.zip)

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/cheatasm

@@ -0,0 +1,2 @@
+#!/bin/bash
+opbasm -6 -x -m 1024 $*

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/cheatzip

@@ -0,0 +1,7 @@
+#!/bin/bash
+FILE=$(basename $1 .s)
+opbasm -6 -x -m 1024 $FILE.s || exit $?
+pico2hex $FILE.hex
+zip cheat.zip $FILE.bin || exit $?
+sshpass -p 1 scp cheat.zip root@MiSTer.home:/media/fat/games/mame
+

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/ecofghtr.s

@@ -0,0 +1,126 @@
+; use "cheatzip" script to assemble and send to MiSTer
+
+; The LED will blink if the cheat bits 7:0 are enabled
+; CPSx work RAM offset = 30'0000h
+
+; Register use
+; SA = frame counter
+; SB = LED
+
+    ; enable interrupt
+    load sa,0   ; SA = frame counter, modulo 60
+    load sb,0
+BEGIN:
+    output s0,0x40
+
+    ; Detect blanking
+    input s0,0x80
+    and   s0,0x20;   test for blanking
+    jump z,inblank
+    jump notblank
+inblank:
+    fetch s1,0
+    test s1,0x20
+    jump z,notblank
+    store s0,0  ; stores last LVBL
+    call ISR ; do blank procedure
+    jump BEGIN
+notblank:
+    store s0,0
+    jump BEGIN
+
+ISR:
+    input sf,0x10
+    test sf,0xff
+    jump z,.nothing
+
+    compare sa,0
+    jump nz,PARSE_FLAGS
+    ; invert LED signal
+    add sb,1
+    jump PARSE_FLAGS
+.nothing:
+    load sb,0      ; turn off LED
+    jump CLOSE_FRAME
+
+PARSE_FLAGS:
+    ; interrupt routine
+    input sf,0x10
+    test  sf,1      ; bit 0
+    jump Z,TEST_FLAG1
+    ; Infinite Credits
+    ; FF02E8=09 -> (02E8/2+30'0000) = 300174
+    load  s0,0x74
+    load  s1,0x01
+    load  s2,0x30
+    load  s3,0
+    load  s4,9
+    load  s5,1
+    call  WRITE_SDRAM
+
+TEST_FLAG1:
+    input sf,0x10
+    test  sf,2      ; bit 1
+    jump Z,TEST_FLAG2
+    ; Infinite Lives
+    ; FFF5F2=09  -> (F5F2/2+30'0000) = 307AF9
+    load  s0,0xf9
+    load  s1,0x7A
+    load  s2,0x30
+    load  s3,0
+    load  s4,9
+    load  s5,1
+    call  WRITE_SDRAM
+
+TEST_FLAG2:
+    input sf,0x10
+    test  sf,4      ; bit 1
+    jump Z,TEST_FLAG3
+    ; Invincibility
+    ; FF877A=FF -> 3043BD once per second
+    compare sa,0
+    jump nz,TEST_FLAG3
+    load  s0,0xBD
+    load  s1,0x43
+    load  s2,0x30
+    load  s3,0
+    load  s4,0xff
+    load  s5,1
+    call  WRITE_SDRAM
+
+TEST_FLAG3:
+CLOSE_FRAME:
+    output sb,6     ; LED
+    ; Frame counter
+    add sa,1
+    compare sa,59'd
+    jump nz,.else
+    load sa,0
+.else:
+    return
+    ;returni ENABLE
+
+    ; SDRAM address in s2-s0
+    ; SDRAM data out in s4-s3
+    ; SDRAM data mask in s5
+    ; Modifies sf
+WRITE_SDRAM:
+    output s5, 5
+    output s4, 4
+    output s3, 3
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0xC0   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    return z
+    jump .loop
+
+default_jump fatal_error
+fatal_error:
+    jump fatal_error
+
+    address 3FF    ; interrupt vector
+    jump ISR

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/ghouls.s

@@ -0,0 +1,173 @@
+; use "cheatzip" script to assemble and send to MiSTer
+
+; The LED will blink if the cheat bits 7:0 are enabled
+; CPSx work RAM offset = 30'0000h
+
+; Register use
+; SA = frame counter
+; SB = LED
+
+    ; enable interrupt
+    load sa,0   ; SA = frame counter, modulo 60
+    load sb,0
+    call CLS
+BEGIN:
+    output s0,0x40
+
+    ; Detect blanking
+    input s0,0x80
+    and   s0,0x20;   test for blanking
+    jump z,inblank
+    jump notblank
+inblank:
+    fetch s1,0
+    test s1,0x20
+    jump z,notblank
+    store s0,0  ; stores last LVBL
+    call ISR ; do blank procedure
+    jump BEGIN
+notblank:
+    store s0,0
+    jump BEGIN
+
+ISR:
+    input sf,0x10
+    test sf,0xff
+    jump z,.nothing
+
+    compare sa,0
+    jump nz,PARSE_FLAGS
+    ; invert LED signal
+    add sb,1
+    jump PARSE_FLAGS
+.nothing:
+    load sb,0      ; turn off LED
+    load s0,0      ; disable screen display
+    output s0,0xa
+    jump SCREEN
+
+PARSE_FLAGS:
+    ; enable screen display
+    load s0,1
+    output s0,0xa
+
+    input sf,0x10
+    and   sf,7      ; bits 2:0
+    jump Z,SCREEN
+    ; P1 weapon selection
+    ; FF07C6=weapon  -> (7C6/2+30'0000) = 3003e3
+    load  s0,0xe3
+    load  s1,0x03
+    load  s2,0x30
+    load  s3,0
+    load  s4,sf
+    sub   s4,1  ; weapon code starts from 0
+    load  s5,1
+    call  WRITE_SDRAM
+
+SCREEN:
+    ; Show the number of lives
+    ; FF07AD -> 3003d6 (MSB)
+    load  s0,0xd6
+    load  s1,0x03
+    load  s2,0x30
+    call  READ_SDRAM
+    load  s0,0x44
+    load  s1,s7
+    call WRITE_HEX
+    load  s1,s6
+    call WRITE_HEX
+
+CLOSE_FRAME:
+    output sb,6     ; LED
+    ; Frame counter
+    add sa,1
+    compare sa,59'd
+    jump nz,.else
+    load sa,0
+.else:
+    return
+    ;returni ENABLE
+
+    ; s0 screen address
+    ; s1 number to write
+    ; modifies s2
+    ; s0 updated to point to the next column
+WRITE_HEX:
+    output s0,8
+    load s2,s1
+    sr0 s2
+    sr0 s2
+    sr0 s2
+    sr0 s2
+    call WRITE_HEX4
+    add s0,1
+    output s0,8
+    load s2,s1
+    call WRITE_HEX4
+    add s0,1    ; leave the cursor at the next column
+    return
+
+    ; s2 number to write
+    ; modifies s2
+WRITE_HEX4:
+    and s2,f
+    compare s2,a
+    jump nc,.over10
+    jump z,.over10
+    add s2,16'd
+    jump .write
+.over10:
+    add s2,23'd
+.write:
+    output s2,9
+    return
+
+CLS:
+    load s0,0
+    load s1,0
+.loop:
+    output s0,8
+    output s1,9
+    add s0,1
+    jump nc,.loop
+
+    ; SDRAM address in s2-s0
+    ; SDRAM data out in s4-s3
+    ; SDRAM data mask in s5
+    ; Modifies sf
+WRITE_SDRAM:
+    output s5, 5
+    output s4, 4
+    output s3, 3
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0xC0   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    return z
+    jump .loop
+
+    ; Modifies sf
+    ; Read data in s7,s6
+READ_SDRAM:
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0x80   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    jump nz,.loop
+    input s6,6
+    input s7,7
+    return
+
+default_jump fatal_error
+fatal_error:
+    jump fatal_error
+
+    address 3FF    ; interrupt vector
+    jump ISR

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/led.s

@@ -0,0 +1,63 @@
+    load sa,0   ; SA = frame counter, modulo 60
+    load sb,0   ; SB = LED
+BEGIN:
+    output s0,0x40
+
+    ; Detect blanking
+    input s0,0x80
+    and   s0,0x20;   test for blanking
+    jump z,inblank
+    jump notblank
+inblank:
+    fetch s1,0
+    test s1,0x20
+    jump z,notblank
+    store s0,0  ; stores last LVBL
+    call ISR ; do blank procedure
+    jump BEGIN
+notblank:
+    store s0,0
+    jump BEGIN
+
+ISR:
+    ; interrupt routine
+    compare sa,59'd
+    jump nz,.not59
+    ; invert LED signal
+    add sb,1
+    output sb,6
+.not59:
+
+    ; Frame counter
+    add sa,1
+    compare sa,60'd
+    jump nz,.else
+    load sa,0
+.else:
+    return
+    ;returni ENABLE
+
+    ; SDRAM address in s2-s0
+    ; SDRAM data out in s4-s3
+    ; SDRAM data mask in s5
+    ; Modifies sf
+WRITE_SDRAM:
+    output s5, 5
+    output s4, 4
+    output s3, 3
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0xC0   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    return z
+    jump .loop
+
+default_jump fatal_error
+fatal_error:
+    jump fatal_error
+
+    address 3FF    ; interrupt vector
+    jump ISR

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cheat/sf2hf.s

@@ -0,0 +1,126 @@
+; use "cheatzip" script to assemble and send to MiSTer
+
+; The LED will blink if the cheat bits 7:0 are enabled
+; CPSx work RAM offset = 30'0000h
+
+; Register use
+; SA = frame counter
+; SB = LED
+
+    enable interrupt
+    load sa,0   ; SA = frame counter, modulo 60
+    load sb,0
+BEGIN:
+    output s0,0x40  ; watchdog
+    jump BEGIN
+
+ISR:
+    input sf,0x10
+    test sf,0xff
+    jump z,.nothing
+
+    compare sa,0
+    jump nz,PARSE_FLAGS
+    ; invert LED signal
+    add sb,1
+    jump PARSE_FLAGS
+.nothing:
+    load sb,0      ; turn off LED
+    jump CLOSE_FRAME
+
+PARSE_FLAGS:
+    ; interrupt routine
+    input sf,0x10
+    test  sf,1      ; bit 0
+    jump Z,TEST_FLAG1
+    ; Infinite Time
+    ; Read FF8AC2 => 304561 and check that its zero
+    load  s0,0x61
+    load  s1,0x45
+    load  s2,0x30
+    call  READ_SDRAM
+    compare s7,0
+    jump nz,char_select
+    ; Read FF8Abe => 30455f and check that its greater than one
+    load  s0,0x5f
+    load  s1,0x45
+    load  s2,0x30
+    call  READ_SDRAM
+    compare s7,1
+    jump z,char_select  ; zero flag set, so the value was equal to 1
+    jump c,char_select  ; carry flag set, so the value was below 1
+
+    ; FF8ABE=9928 -> (8ABE/2+30'0000) = 30455F (round time)
+    load  s0,0x5F
+    load  s1,0x45
+    load  s2,0x30
+    load  s3,99 ; For M68000, the upper byte goes in s3
+    load  s4,28
+    load  s5,0
+    call  WRITE_SDRAM
+
+char_select:
+    ; always write this value
+    ; FFDDA2=203C -> (DDA2/2+30'0000) = 306ED1 (char select time)
+    load  s0,0xD1
+    load  s1,0x6E
+    load  s2,0x30
+    load  s3,20
+    load  s4,3C
+    load  s5,0
+    call  WRITE_SDRAM
+
+TEST_FLAG1:
+
+TEST_FLAG2:
+
+TEST_FLAG3:
+CLOSE_FRAME:
+    output sb,6     ; LED
+    ; Frame counter
+    add sa,1
+    compare sa,59'd
+    jump nz,.else
+    load sa,0
+.else:
+    returni ENABLE
+
+    ; SDRAM address in s2-s0
+    ; SDRAM data out in s4-s3
+    ; SDRAM data mask in s5
+    ; Modifies sf
+WRITE_SDRAM:
+    output s5, 5
+    output s4, 4
+    output s3, 3
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0xC0   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    return z
+    jump .loop
+
+    ; Modifies sf
+    ; Read data in s7,s6
+READ_SDRAM:
+    output s2, 2
+    output s1, 1
+    output s0, 0
+    output s1, 0x80   ; s1 value doesn't matter
+.loop:
+    input  sf, 0x80
+    compare sf, 0xC0
+    jump nz,.loop
+    input s6,6
+    input s7,7
+    return
+
+default_jump fatal_error
+fatal_error:
+    jump fatal_error
+
+    address 3FF    ; interrupt vector
+    jump ISR

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/cpus.md

@@ -0,0 +1,81 @@
+# CPUs
+
+Some CPUs are included in JTFRAME. Some of them can be found in other repositories in Github but the versions in JTFRAME include clock enable inputs and other improvements.
+
+CPUs should have their respective license file in the folder, or directly embedded in the files. Note that they don't use GPL3 but more permissive licenses.
+
+Many CPUs have convenient wrappers that add cycle recovery functionality, or
+that allow the selection between different modules for the same CPU.
+
+CPU selection is done via verilog [macros](macros.md).
+
+Resource utilization based on MiST
+
+Processor   | Logic Cells  |  BRAM |  Remarks
+------------|--------------|-------|-----------------
+M68000      |  5171        |    6  |  fx68k
+i8751       |  4019        |    5  |  jtframe_8751mcu
+M6809       |  2992        |    0  |  mc6809i
+Konami CPU  |  2521        |    2  |  JTKCPU
+Z80         |  2476        |    2  |  jtframe_sysz80 (T80s)
+jt680x      |  1556        |    0  |  6801 variant (ucode synthesized as logic)
+jt680x      |   516        |   19  |  6801 variant (ucode synthesized as BRAM)
+6801_core.sv|  1039        |    0  |  3rd party 6801 core
+6502        |   832        |    0  |  T65 (VHDL)
+6502        |   937        |    0  |  chip_6502 (Andrew Holme)
+PicoBlaze   |   950        |    0  |  PauloBlaze
+MCS48       |   657        |    3  |  T48 (VHDL)
+
+## M68000
+
+fx68k is the preferred module. Because it designed in System Verilog, it cannot be simulated with Verilator. JTCORES points to a fork that contains a version manually converted to Verilog.
+
+A [tool](https://github.com/ijor/fx68k/issues/16) capable of making the conversion from System Verilog to Verilog automatically appeared later. It has not been tested in JTCORES yet.
+
+## Z80
+
+The two basic modules to instantiate are:
+
+- jtframe_sysz80_nvram
+- jtframe_sysz80
+
+These two modules offer a Z80 CPU plus:
+
+- A connected RAM (or NVRAM)
+- Automatic interrupt clear if CLR_INT parameter is set
+- Automatic wait cycles inserted on M1 falling edge if M1_WAIT is set larger than zero
+
+## 6502
+
+There are two versions of the 6502 in JTFRAME:
+
+- the T65, a re-implementation in VHDL
+- the chip6502, a 1:1 translation of the original netlist by [Andrew Holme](http://www.aholme.co.uk/6502/Main.htm)
+
+The netlist to verilog conversion requires a clock at least 16x faster than the target 6502 speed, and a 50% duty cycle for a PHI signal that represents the actual 6502 clock. The output has glitches similar to the original ones (not necessarily at the same time). Because of this, the connection is not straight forward. The wrapper [jtframe_mos6502](../hdl/cpu/jtframe_mos6502.v) takes care of these things. However, trying to use the ready signal so the CPU waits for memory data does not seem to operate reliably.
+
+Because of the issue with the ready signal, the recommended CPU core is the T65 one. T65 also has a smaller footprint.
+
+## VHDL
+
+Verilator cannot simulate VHDL. It is possible to run mixed language simulations in _jtframe_ by using _modelsim_ in the simulation with `jtsim -modelsim`. However, this is very slow. In order to speed it up, convert the modules to verilog first using [ghdl](https://github.com/ghdl).
+
+Note that `@` must go before the file name. As usual, file list order for VHDL is important.
+
+```
+ghdl -a -fsynopsys @gatherfile
+ghdl synth --out=verilog toplevel_name > toplevel_name.v
+```
+
+To use `ghdl` in Ubuntu declare this function:
+
+```
+ghdl ()
+{
+    docker run -ti -w/mnt -v `pwd`:/mnt ghdl/ghdl:ubuntu22-llvm-11 ghdl $*
+}
+```
+
+When converting VHDL to Verilog, it might be needed to rename instance names because they are used by the tool to generate signal names and that can create duplications in the verilog code. See [this issue](https://github.com/ghdl/ghdl/issues/2329).
+
+Another valid tool is [VHD2VL](https://github.com/ldoolitt/vhd2vl)

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/credits.md

@@ -0,0 +1,55 @@
+# Credits Screen
+
+Credits can be displayed using the module *JTFRAME_CREDITS*. This module needs the following files inside the patrons folder:
+
+Input File | Output File    | Tool      | Function
+-----------|----------------|-----------|--------------------------------------------
+ msg       | msg.hex        | msg2hex   | text shown
+ avatars   | avatar.hex     | avatar.py | avatar images. 4bpp indexed
+ avatars   | avatar_pal.hex | avatar.py | avatar paletters
+ lut       | lut.hex        | lut2hex   | avatar tiles location in 8-pixel multiples
+
+**avatars** contains a line with the path from $JTROOT or $JTROOT/cores (if cores exists) to the PNG image.
+There should be one line per image.
+
+**lut** contains the object look-up table. Each line has four fields:
+
+1. Tile code
+2. x position
+3. y position
+4. Palette
+
+* Line starting with # character are treated as comments
+* A line can start with the scape code **\6,** which means that the following
+  four fields should be expanded to a full 2x3 sprite, adjusting tile code
+  and positions accordingly
+* Another scape code is **\9,** and will expand to a full 3x3 sprite
+* The table end is marked by an object with ID 255
+
+avatar.py needs a .png image that complies with:
+
+1. x-y sizes are multiples of 8
+2. Maximum 16 colours in the image
+3. Alpha channel present in the PNG
+4. Image format is RGB (not indexed)
+
+Once the three files msg, avatars and lut are available, jtcore will process them as part of the compilation.
+
+## JTFRAME_CREDITS
+
+Features 1-bpp text font and 4-bpp objects. Enable it with macro **JTFRAME_CREDITS**. By default there are three pages of memory reserved for this. If a different number is needed define the macro **JTFRAME_CREDITS_PAGES** with the right value. Avatars are enabled with **JTFRAME_AVATARS**
+
+**JTFRAME_CREDITS** is also added by the script *jtcore* if the file patrons/msg exists.
+
+If the same core plays horizontal and vertical games, jtframe_credits will rotate the credits. The credits text file must be designed to fit both scenarios. If the vertical case is not as important, the credits can set to always show in horizontal using **JTFRAME_CREDITS_NOROTATE** or to not show for vertical games **JTFRAME_CREDITS_HIDEVERT**.
+
+## msg2hex
+Converts from a text file (patrons/msg) to a hex file usable by *JTFRAME_CREDITS*.
+Type text for ASCII conversion. Escape characters can be introduced by \ with the following meaning:
+
+Escape              |  Meaning
+--------------------|------------------------------
+R                   | RED   palette (index 0)
+G                   | GREEN palette (index 1)
+B                   | BLUE  palette (index 2)
+W                   | WHITE palette (index 3)

snapshots/jotego_jtcores_pr1100/modules/jtframe/doc/debug_list.md

@@ -0,0 +1,90 @@
+# Debug Check List
+
+If a core synthesizes correctly but shows odd behaviour, these are some of the items that may have gone wrong
+
+## Total Failure
+- Is the CPU memory size correct? The game may boot with a smaller RAM but fail later on
+- Are the clock enable signals applied to the right clock domain? Check the CPU clk/clk_en pair
+- Is the port direction correct in all modules? Quartus will fail to drive signals that are defined in all modules as inputs
+- Are level interrupts held long enough?
+- Strobe signals from one clock domain to another, or one cen-domain to another must use jtframe strobe synchronizers
+- Is the frame interrupt getting to the CPU?
+- Try disabling cycle recovery in the CPUs
+
+## Video Artefacts
+- The shifted screen counter should keep the right sequence around LVBL/LHBL transitions
+- Flipped counters are discontinuous around blanking edges
+
+## Wrong Colours
+- Is JTFRAME_COLORW correct?
+- Is the bit plane order correct?
+- If a color PROM is used, the bit plane order must be set right at the input
+- Is the right part of the palette selected?
+
+## Sound Problems
+- Are interrupts coming correctly to the CPU?
+- If unsigned and signed output modules are used for sound, the unsigned ones must be converted to signed using *jtframe_dcrm*
+
+# CPU Debugging
+
+The `jtutil vcd` utility can compare MAME trace files with simulation VCDs. But step comparison with MAME is hard because of interrupts happening at different times and the number of stack pointer transitions during in and out of the interrupt service. Workarounds:
+
+1. Disable interrupts. If the CPU error may still arise if CPUs are disabled.
+2. Locate the interrupt wait loop. Replace the last branch instruction for a halt/sync (wait for interrupt) and then a branch. This may still not work if the program does not get to the wait loop in busy frames. It will still be useful in situations where the CPU makes a count down for an interrupt, like the ADC interrupt in NeoGeo Pocket.
+3. Create a new CPU instruction both on MAME and FPGA that does a BRANCH and a software interrupt. This will replace the original branch. Disable external interrupts. Now the software will self-interrupt ones all the between-frame calculations are completed. This should perfectly match the emulated and simulated CPUs.
+
+# New Core Check List
+
+This text can be used in GitHub to generate a check list to use during code development
+
+## Beta core development
+
+**Ground Work**
+- [ ] Schematics
+- [ ] Hardware dependencies
+- [ ] SDRAM mapping (mame2mra.toml and mem.yaml)
+- [ ] Audio information in mem.yaml
+**RTL**
+- [ ] Logic connected
+- [ ] Tilemap logic
+- [ ] Sprite logic
+- [ ] Color mixer
+- [ ] Graphics are correct
+- [ ] Top level simulation hooked up correctly
+- [ ] Simulation starts up correctly
+- [ ] Music sounds
+- [ ] No sound clipping
+- [ ] Synthesis ok
+- [ ] DIP switches work
+- [ ] Playable
+**Final Verification**
+- [ ] Button names in mame2mra.toml
+- [ ] Add Patreon message
+- [ ] Update README file
+- [ ] Check MiSTer
+- [ ] Check Pocket
+- [ ] Write Patreon entry
+
+## Beta core publishing
+
+**JTBIN checks**
+- [ ] No files for non-beta RBF in JTBIN
+- [ ] JTBIN has been comitted and pushed
+- [ ] Run update_all and check the files
+- [ ] Files in Patreon
+**After publishing**
+- [ ] Tweet about the beta
+
+## Public release
+
+- [ ] Remove jtbeta.zip from MRAs
+- [ ] Recompile MiSTer without beta
+- [ ] Recompile Sockit without beta
+- [ ] Copy minor platforms to JTBIN
+- [ ] Copy Pocket files to JTBIN
+- [ ] Push branch to GitHub, if a local remote was used
+- [ ] Make source code repository public, if it was private
+**Unsupported games**
+- [ ] mame2mra.toml discards unsupported games
+- [ ] No MRA/JSON files for unsupported games in any repository
+- [ ] issue in main repository listing unsupported games as possible _new cores_