	title	RAID 6809 DEBUGGER
*
* RAID: Runtime Aid for Interactive Debugging (6809 debugger)
*
* Copyright 1983-2005 Dave Dunfield
* All rights reserved.
*
ROM	EQU	OSUTIL-4096	RAID PROGRAM STORAGE (JUST UNDER UTILS)
RAM	EQU	ROM-160		RAID RAM
STACK	EQU	ROM		SYSTEM STACK (TOP OF RAM)
DDADR	EQU	19		DIRECTORY DISK ADDRESS OFFSET
DRADR	EQU	21		DIRECTORY LOAD ADDRESS
*
	ORG	RAM		MONITOR RAM
*
SWIADR	RMB	2		SWI VECTOR ADDRESS
DEVICE	RMB	2		INPUT VECTOR
SAVCC	RMB	1		SAVED CONDITION CODE REGISTER
SAVA	RMB	1		SAVED 6809 A REGISTER
SAVB	RMB	1		SAVED 6809 B REGISTER
SAVDP	RMB	1		SAVED DIRECT PAGE REGISTER
SAVX	RMB	2		SAVED X REGISTER
SAVY	RMB	2		SAVED Y REGISTER
SAVU	RMB	2		SAVED U REGISTER
SAVPC	RMB	2		SAVED PROGRAM COUNTER
SAVS	RMB	2		SAVED S REGISTER
TEMP	RMB	2		TEMPORARY STORAGE
HELD	RMB	1		OUTPUT IS HELD
STPFLG	RMB	1		REGISTER DISPLAY WHILE STEPPING FLAG
PTRSAV	RMB	2		SINGLE STEP AND DISASSEMBLER CODE POINTER
INSTYP	RMB	1		DISASSEMBLED INSTRUCTION TYPE
POSBYT	RMB	1		POSTBYTE STORAGE AREA
REGIND	RMB	2		INDIRECT REGISTER ADDRESS
BRKTAB	RMB	24		BREAKPOINT TABLE
DSPBUF	RMB	50		DISASSEMBLER DISPLAY BUFFER
INSRAM	RMB	7		INSTRUCTION EXECUTION ADDRESS
*
	ORG	ROM		MONITOR CODE
*
* INITIALIZATIONS
*
RAID	CMPA	#'?'		QUERY OPERAND?
	BNE	RAID1		NO, ITS OK
	SSR	25		DISPLAY MESSAGE
	FCCZ	'Use: RAID[/<device] [<load file> [<operands>]]'
	RTS
RAID1	LDS	#STACK		SET UP STACK
	LDX	#SAVCC		POINT TO START
RAID2	CLR	,X+		CLEAR IT
	CMPX	#DSPBUF		AT BUFFER?
	BLO	RAID2		KEEP GOING
	LDD	#RAM		DEFAULT STACK AT TOP OF RAM
	STD	SAVS		SAVE IT
	LDA	#$D0		SET CC
	STA	SAVCC		SAVE IT
* GET RAID CONSOLE DEVICE
	SSR	39		GET CONSOLE DEVICE
	STA	>DEVICE		SET IT
	LDA	,Y		GET CHAR
	CMPA	#'/'		QUALIFIER?
	BNE	NOQUAL		NO, ITS OK
	LEAY	1,Y		ADVANCE
	SSR	6		GET NUMBER
	LBNE	ABORT		INVALID, EXIT
	ANDB	#7		INSURE IN RANGE
	STB	>DEVICE		SAVE IT
* IF A FILE IS SPECIFIED, LOAD IT
NOQUAL	SSR	4		MORE PARMS?
	BEQ	NOPARM		NO, ITS OK
	SSR	10		GET FILENAME
	LBNE	ABORT		ERROR
	SSR	70		LOOK IT UP
	LBNE	ABORT		ERROR
	LDD	DDADR,X		GET DISK ADDRESS
	LDX	DRADR,X		GET RUN ADDRESS
	STX	>SAVPC		PT TO IT
	SSR	78		LOAD FILE IN
	LBNE	ABORT		ERROR
	LBSR	WRMSG		MESSAGE
	FCCZ	'Loaded at $'
	LDD	>SAVPC		GET ADDR BACK
	LBSR	WRDOUT		OUTPUT
	LBSR	LFCR		NEW LINE
NOPARM	STY	>SAVY		SAVE PTR
* PATCH INTO DOS FOR VECTORS
	LDX	#SWIHND		POINT TO HANDLER
	LDA	#20		SWI VECTOR
	SSR	103		SET IT
	STD	>SWIADR		SAVE OLD HANDLER ADDRESS	
MAIN	LDS	#STACK		FIX STACK IN CASE ERROR
	LBSR	WRMSG		OUTPUT MESSAGE
	FCCZ	'Raid> '
	LBSR	GETECH		GET CHARACTER
	LBSR	SPACE		OUTPUT SPACE
	LDX	#CMDTAB		LOOK UP COMMANDS
LKCMD	CMPA	,X+		IS THIS IT
	BEQ	CFOUND		YES
	LEAX	2,X		SKIP ADDRESS
	TST	,X		HIT END?
	BNE	LKCMD		NO, KEEP LOOKING
* ERROR HAS OCCURED
ERROR	LBSR	WRMSG		OUTPUT MESSAGE
	FCC	' ?'
	FCB	$0D
	BRA	MAIN		TRY AGAIN
* COMMAND WAS FOUND
CFOUND	JSR	[,X]		EXECUTE CODE
	BRA	MAIN		AND TRY AGAIN
* COMMAND LOOKUP TABLE
CMDTAB	FCB	'M'		DISPLAY MEMORY
	FDB	MEMORY		ADDRESS OF HANDLER
	FCB	'E'		SUBSTITUTE MEMORY
	FDB	SUBMEM
	FCB	'Q'		EXIT DEBUGGER
	FDB	QUIT
	FCB	'D'		DISASSEMBLE
	FDB	DISASM
	FCB	'R'		DISPLAY REGISTERS
	FDB	DISREG
	FCB	'C'		CHANGE REGISTER
	FDB	CHGREG
	FCB	'V'		VIEW BREAKPOINTS
	FDB	DSPBRK
	FCB	'B'		SET BREAKPOINT
	FDB	SETBRK
	FCB	'S'		STEP
	FDB	GOSTEP
	FCB	'G'		GO
	FDB	GOEXEC
	FCB	0		MARK END OF TABLE
*
* 'Q'UIT & RETURN TO OS
*
QUIT	LBSR	LFCR		NEW LINE
	LDX	>SWIADR		GET VECTOR
	LDA	#20		SWI VECTOR
	SSR	103		SET IT
	CLRA
ABORT	SSR	0
*
* 'M'EMORY COMMAND, DISPLAY MEMORY
*
MEMORY	LBSR	GETRNG		GET ADDRESS
	BNE	ERROR		INVALID
	STD	TEMP		SAVE
MEM1	LBSR	LFCR		NEW LINE
	LBSR	CHKCHR		CHECK FOR CHAR
	LBEQ	MAIN		ESCAPE, QUIT
	TFR	X,D		GET ADDRESS
	PSHS	A,B		SAVE FOR LATER
	LBSR	WRDOUT		DISPLAY
	LDB	#16		DISPLAY 16 TO A LINE
MEM2	LBSR	SPACE		OUTPUT A SPACE
	BITB	#3		ON A BOUNDARY?
	BNE	MEM3		NO, SPACE
	LBSR	SPACE		EXTRA SPACE
MEM3	LDA	,X+		GET BYTE
	LBSR	HEXOUT		DISPLAY
	DECB			REDUCE COUNT
	BNE	MEM2		CONTINUE
	LDB	#4		FOUR SPACE
MEM4	LBSR	SPACE		DISPLAY A SPACE
	DECB			REDUCE COUNT
	BNE	MEM4		CONTINUE
	PULS	X		RESTORE X
	LDB	#16		COUNT OF 16
MEM5	LDA	,X+		GET CHAR
	CMPA	#' '		<SPACE
	BLO	MEM6		CONVERT TO DOT
	CMPA	#$7F		PRINTABLE?
	BLO	MEM7		OK TO DISPLAY
MEM6	LDA	#'.'		CHANGE TO DOT
MEM7	LBSR	PUTCHR		OUTPUT
	DECB			REDUCE COUNT
	BNE	MEM5		DISPLAY THEM ALL
	CMPX	TEMP		PAST END?
	BLS	MEM1		NO, KEEP GOING
	LBRA	LFCR		NEW LINE
*
* 'E'DIT MEMORY COMMAND
*
SUBMEM	LBSR	GETADR		GET ADDRESS
	LBNE	ERROR		INVALID
	TFR	D,X		COPY
SUBM1	LBSR	LFCR		NEW LINE
	TFR	X,D		GET ADDRESS
	LBSR	WRDOUT		OUTPUT
	LDB	#8		NEW COUNT
SUBM2	LBSR	SPACE		SEPERATOR
	LDA	,X		GET BYTE
	LBSR	HEXOUT		DISPLAY
	LDA	#'-'		PROMPT
	LBSR	PUTCHR		OUTPUT
	LBSR	GETBYT		GET A BYTE
	BNE	SUBM4		INVALID
	STA	,X		RESAVE
SUBM3	LEAX	1,X		ADVANCE
	DECB			REDUCE COUNT
	BNE	SUBM2		MORE, CONTINUE
	BRA	SUBM1		NEW LINE
SUBM4	CMPA	#$0D-$37	CR?
	LBEQ	LFCR		IF SO, QUIT
	CMPA	#' '-$37	SPACE?
	BNE	SUBM5		NO
	LBSR	SPACE		FILL FOR TWO DIGITS
	BRA	SUBM3		ADVANCE
SUBM5	CMPA	#$08-$37	BACKSPACE?
	LBNE	ERROR		INVALID
	LEAX	-1,X		BACKUP
	BRA	SUBM1		NEW LINE
*
* 'D'ISASSEMBLE MEMORY COMMAND
*
DISASM	LBSR	GETRNG		GET ADDRESS
	LBNE	ERROR		INVALID, QUIT
	TFR	X,Y		COPY TO Y
	STD	TEMP		SAVE
	LBSR	LFCR		NEW LINE
	LDU	#DSPBUF		POINT TO INPUT BUFFER
DISS1	LBSR	DISASS		DISASSEMBLE
	TFR	U,X		COPY
	LBSR	WRLIN		OUTPUT
	LBSR	CHKCHR		END?
	BEQ	DISS2		YES, QUIT
	CMPY	TEMP		OVER?
	BLO	DISS1		TRY AGAIN
DISS2	RTS
*
* 'R'EGISTER DISPLAY COMMAND
*
DISREG	LDX	#REGTXT		POINT TO TEXT
	LDY	#SAVCC		POINT TO VALUE
	BSR	RSUB1		'CC='
	LBSR	WRLIN		' ['
	LDU	#CCBITS		POINT TO BIT TABLE
	LDB	-1,Y		GET BITS BACK
	PSHS	Y		SAVE POINTER
	LDY	#8		EIGHT BITS IN BYTE
REGB1	LDA	,U+		GET BIT IDENTIFIER
	ASLB			IS IT SET?
	BCS	RBITS		YES, DISPLAY IT
	LDA	#'-'		NO, DISPLAY DASH
RBITS	LBSR	PUTCHR		OUTPUT A CHARACTER
	LEAY	-1,Y		REDUCE COUNT
	BNE	REGB1		MORE TO GO
	PULS	Y		RESTORE Y
	BSR	RSUB1		'] A='
	BSR	RSUB1		' B='
	BSR	RSUB1		' DP='
	BSR	RSUB2		' X='
	BSR	RSUB2		' Y='
	BSR	RSUB2		' U='
	BSR	RSUB2		' PC='
	BSR	RSUB2		' S='
	LBRA	LFCR		QUIT
* DISPLAY 8 BIT REGISTER VALUE
RSUB1	LBSR	WRLIN		OUTPUT BYTE VALUE
	LDA	,Y+		GET REGISTER VALUE
	LBRA	HEXOUT		OUTPUT IN HEX
* DISPLAY 16 BIT REGISTER VALUE
RSUB2	LBSR	WRLIN		OUTPUT WORD VALUE
	LDD	,Y++		GET REGISTER VALUE
	LBRA	WRDOUT		OUTPUT IN HEX
* TABLE OF TEXT FOR REGISTER DISPLAY
REGTXT	FCCZ	'CC='
	FCCZ	' ['
	FCCZ	'] A='
	FCCZ	' B='
	FCCZ	' DP='
	FCCZ	' X='
	FCCZ	' Y='
	FCCZ	' U='
	FCCZ	' PC='
	FCCZ	' S='
* TABLE OF CONDITION CODE BIT MEANINGS
CCBITS	FCC	'EFHINZVC'
*
* 'C'HANGE REGISTER COMMAND
*
CHGREG	LBSR	GETECH		GET OPERAND
	CMPA	#' '		A+B?
	BEQ	CHG4		YES
	LDX	#CHGTAB		POINT TO TABLE
	CLRB			ZERO INDICATOR
CHG1	CMPA	,X		IS THIS IT?
	BEQ	CHG2		YES
	INCB			ADVANCE COUNT
	TST	,X+		END OF TABLE
	BNE	CHG1		NO, KEEP TRYING
	LBRA	ERROR		INDICATE ERROR
CHG2	LBSR	SPACE		OUTPUT SPACE
	LDX	#SAVCC		POINT TO START OF REGISTERS
	CMPB	#4		16 BIT?
	BHS	R16		YES
	LEAX	B,X		OFFSET TO ADDRESS
	LBSR	GETBYT		GET NEW VALUE
	LBNE	ERROR		INVALID
	STA	,X		SAVE IN REGISTER
	BRA	CHG3		AND QUIT
CHG4	LBSR	WRMSG		OUTPUT MESSAGE
	FCCZ	'[AB] '
	LDX	#SAVA		POINT TO 'D'
	BRA	R17		MAKE LIKE 16 BIT REG
R16	LEAX	4,X		OFFSET TO 16 BIT REGISTERS
	SUBB	#4		CONVERT TO ZERO ORIGIN
	ASLB			DOUBLE FOR WORD VALUES
	LEAX	B,X		MOVE TO CORRECT OFFSET
R17	LBSR	GETADR		GET WORD VALUE
	LBNE	ERROR		INVALID
	STD	,X		SET REGISTER VALUE
CHG3	LBRA	LFCR		QUIT
* TABLE OF REGISTER NAMES
CHGTAB	FCCZ	'CABDXYUPS'
*
* 'V'IEW BREAKPOINTS
*
DSPBRK	LDA	#'0'		START WITH BRKPT ZERO
	LDX	#BRKTAB		POINT TO TABLE
DSPB1	PSHS	A		SAVE NUMBER
	LDA	#'B'		PRECEDE WITH 'B'
	LBSR	PUTCHR 		OUTPUT
	LDA	,S		GET NUMBER BACK
	LBSR	PUTCHR		OUTPUT
	LDA	#'='		AND FOLLOW WITH '='
	LBSR	PUTCHR		OUTPUT
	LDD	,X++		GET VALUE
	BNE	DSPB2		NON-ZERO, DISPLAY
	LBSR	WRMSG		OUTPUT MESSAGE INSTEAD
	FCCZ	'****'
	BRA	DSPB3		CONTINUE
DSPB2	LBSR	WRDOUT		OUTPUT VALUE
DSPB3	LBSR	SPACE		SEPERATE WITH SPACE
	LEAX	1,X		SKIP OPCODE SAVE
	PULS	A		RESTORE NUMBER
	INCA			ADVANCE
	CMPA	#'8'		BEYOND END?
	BLO	DSPB1		NO, CONTINUE
	LBRA	LFCR		NEW LINE AND QUIT
*
* 'B'REAKPOINT COMMAND
*
SETBRK	LBSR	GETECH		GET CHARACTER
	SUBA	#'0'		CONVERT TO NUMBER
	CMPA	#8		IN RANGE?
	LBHS	ERROR		NO, QUIT
	PSHS	A		SAVE NUMBER
	ASLA			DOUBLE FOR 16 BIT VALUES
	ADDA	,S+		TRIPLE FOR OPCODE BYTE
	LDX	#BRKTAB		POINT TO BREAKPOINT TABLE
	LEAX	A,X		ADVANCE TO BREAKPOINT
	LBSR	SPACE		SEPERATE WITH SPACE
	LBSR	GETADR		GET VALUE
	LBNE	ERROR		INVALID
	STD	,X		SAVE IN TABLE
	LBRA	LFCR		NEW LINE AND QUIT
*
* 'S'TEP COMMAND
*
GOSTEP	LBSR	GETADR		GET ADDRESS
	BEQ	GOS1		ADDRESS SUPPLIED, GO
	CMPA	#' '-$37	WAS IT SPACE?
	LBNE	ERROR		NO, ERROR
	BRA	GOS2		CONTINUE
GOS1	STD	SAVPC		SAVE NEW ADDRESS
GOS2	LBSR	LFCR		OUTPUT MESSAGE
GOSTP1	LBSR	STEPDI		STEP AND DISPLAY INSTRUCTION
	TST	STPFLG		DISPLAY REGISTERS?
	BMI	NODSR		NO, DON'T DISPLAY
STPREG	LBSR	DISREG		DISPLAY REGISTERS
NODSR	LBSR	GETCHR		GET KEY FROM TERMINAL
	CMPA	#'?'		DISPLAY REGS?
	BEQ	STPREG		IF SO, DISPLAY
	CMPA	#' '		STEP TO NEXT?
	BEQ	GOSTP1		IF SO, STEP
	CMPA	#$1B		EXIT STEPPING?
	BEQ	GOSTP2		IF SO, QUIT
	CMPA	#$0D		TOGGLE REGISTER DISPLAY?
	BNE	NODSR		IF NOT, IGNORE
	COM	STPFLG		TOGGLE DISPLAY FLAG
	BRA	NODSR		GET NEXT KEY
GOSTP2	RTS
*
* 'G'O COMMAND
*
GOEXEC	LBSR	GETADR		GET ADDRESS FROM TERMINAL
	BEQ	GOEX1		IF ENTERED, EXECUTE THERE
	CMPA	#' '-$37	WAS IT SPACE?
	BEQ	GOEX2		YES, CONTINUE FROM LAST PC
	LBRA	ERROR		INVALID KEY, ABORT
GOEX1	STD	SAVPC		SAVE NEW PROGRAM COUNTER
GOEX2	LBSR	WRMSG		OUTPUT MESSAGE
	FCCZ	' ->$'
	LDD	SAVPC		GET PC ADDRESS
	LBSR	WRDOUT		DISPLAY ON TERMINAL
	LBSR	LFCR		NEW LINE
* STEP ONE INST. BEFORE INSERTING BREAKPOINTS, SO THAT BREAKPOINTS
* CAN BE USED WITHIN LOOPS ETC
	LBSR	STEP		STEP ONE INSTRUCTION
* INSERT BREAKPOINTS
	LDX	#BRKTAB		POINT TO BREAKPOINT TABLE
	LDB	#8		EIGHT BREAKPOINTS
GOEX3	LDY	,X++		GET BREAKPOINT ADDRESS
	BEQ	GOEX4		NO BREAKPOINT, QUIT
	LDA	,Y		GET OPCODE
	STA	,X		SAVE IN TABLE
	LDA	#$3F		GET 'SWI' BREAKPOINT OPCODE
	STA	,Y		SAVE IN CODE SPACE
GOEX4	LEAX	1,X		ADVANCE TO NEXT IN TABLE
	DECB			REDUCE COUNT OF BRKPTS
	BNE	GOEX3		DO ALL EIGHT
	LDS	SAVS		RESTORE STACK POINTER
	LDA	SAVCC		GET SAVED CC
	LDB	SAVDP		GET SAVED DPR
	PSHS	A,B		SAVE ON STACK FOR LAST RESTORE
	LDD	SAVA		RESTORE A, B REGISTERS
	LDX	SAVX		RESTORE X REGISTER
	LDY	SAVY		RESTORE Y REGISTER
	LDU	SAVU		RESTORE U REGISTER
	PULS	CC,DP		RESTORE CC + DP
	JMP	[SAVPC]		EXECUTE USER PGM
*
* GETS A RANGE OF ADDRESS, RETURNS WITH START IN X, END IN D
*
GETRNG	BSR	GETADR		GET FIRST
	BNE	GRGRTS		INDICATE INVALID
	TFR	D,X		SAVE
	LDA	#','		GET COMMA
	LBSR	PUTCHR		OUTPUT
	BSR	GETADR		GET ADDRESS
	BEQ	GRGRTS		RANGE IS OK
	CMPA	#' '-$37	SPACE?
	BNE	GRGRTS		NO, INVALID
	LBSR	WRMSG		OUTPUT MESSAGE
	FCCZ	'FFFF'
	LDD	#$FFFF		ASSUME TOP OF RAM
	ORCC	#4		INDICATE OK
GRGRTS	RTS
*
* GETS AN ADDRESS (IN D) FROM THE INPUT DEVICE
*
GETADR	BSR	GETBYT		GET A BYTE
	BNE	GETB1		INVALID
	TFR	A,B		COPY FOR LATER
	BSR	GETBYT		GET NEXT BYTE
	BNE	GETB1		INVALID
	EXG	A,B		PUT HIGH FIRST
	RTS
*
* GETS A SINGLE BYTE (IN HEX) FROM THE INPUT DEVICE
*
GETBYT	BSR	GETNIB		GET NIBBLE
	BNE	GETB3		BAD
	ASLA			ROTATE
	ASLA			INTO
	ASLA			HIGH
	ASLA			NIBBLE
	PSHS	A		SAVE
	BSR	GETNIB		GET NIBBLE
	BNE	GETB2		INVALID
	ORA	,S+		INSERT HIGH
GETB4	ORCC	#$04		SET 'Z' FLAG
	RTS
GETB2	LEAS	1,S		SKIP SAVED NAME
GETB1	RTS
GETB3	CMPA	#$27-$37	SINGLE QUOTE?
	BNE	GETB1		NO, ABORT
	LBSR	GETCHR		GET A CHARACTER
	LBSR	PUTCHR		ECHO ON TERM
	BRA	GETB4		INDICATE OK, AND RETURN
*
* GETS A SINGLE HEX NIBBLE FROM THE INPUT DEVICE
*
GETNIB	LBSR	GETECH		GET CHAR
	SUBA	#'0'		CONVERT
	CMPA	#9		NUMERIC?
	BLS	GETN1		YES, OK
	SUBA	#7		CONVERT TO ALPHA
	CMPA	#$A		UNDER?
	BLO	GETN2		YES, BAD
	CMPA	#$F		OVER?
	BHI	GETN2		INDICATE BAD
GETN1	ORCC	#$04		SET 'Z' FLAG, INDICATE OK
	RTS
GETN2	ANDCC	#$FB		CLEAR 'Z' FLAG, INDICATE INVALID
	RTS
*
* OUTPUT A WORD (IN HEX) FROM REGISTER D
*
WRDOUT	BSR	HEXOUT		OUTPUT FIRST BYTE
	TFR	B,A		COPY
*
* OUTPUT A BYTE (IN HEX) FROM REGISTER A
*
HEXOUT	PSHS	A		SAVE
	LSRA			ROTATE
	LSRA			UPPER NIBBLE
	LSRA			INTO
	LSRA			LOWER
	BSR	HOUT		OUTPUT
	PULS	A		RESTORE
*
* OUTPUT A NIBBLE (IN HEX) FROM REGISTER A
*
HOUT	ANDA	#$0F		REMOVE OTHER HALF
	ADDA	#'0'		CONVERT TO PRINTABLE
	CMPA	#'9'		IS IT IN RANGE?
	BLS	HOUT1		YES, ITS OK
	ADDA	#7		CONVERT TO ALPHA
HOUT1	BRA	PUTCHR		OUTPUT CHARACTER
*
* WRITE ERROR MESSAGE FOLLOWING TEXT
*
WRMSG	PSHS	X		SAVE X
	LDX	2,S		GET OLD PC
	BSR	WRLIN		OUTPUT LINE
	STX	2,S		UPDATE OLD PC
	PULS	X,PC		RESTORE X, RETURN
*
* DISPLAY MESSAGE(X)
*
WRLIN	LDA	,X+		GET CHAR FROM MESSAGE
	BEQ	WRLND		END, QUIT
	CMPA	#$0D		CR?
	BEQ	LFCR		IF SO, NEW LINE, RETURN
	BSR	PUTCHR		OUTPUT TO TERM
	BRA	WRLIN		KEEP GOING
WRLND	RTS
*
* GET CHAR. FROM TERMINAL, AND ECHO
*
GETECH	LBSR	GETCHR		GET CHARACTER
	CMPA	#' '		SPACE?
	BLO	WRLND		IF < DON'T DISPLAY
	CMPA	#$61		LOWER CASE?
	BLO	PUTCHR		OK
	ANDA	#$5F		CONVERT TO UPPER
	BRA	PUTCHR		ECHO
*
* DISPLAY A SPACE ON THE TERMINAL
*
SPACE	PSHS	A		SAVE A
	LDA	#' '		GET SPACE
	BRA	LFC1		DISLAY AND GO HOME
*
* DISPLAY LINE-FEED, CARRIAGE RETURN ON TERMINAL
*
LFCR	PSHS	A		SAVE
	LDA	#$0A		GET LF
	BSR	PUTCHR		OUTPUT
	LDA	#$0D		GET CR
LFC1	BSR	PUTCHR		OUTPUT
	PULS	A,PC		RESTORE AND GO HOME
*
* WRITE A CHARACTER TO ALL ENABLED OUTPUT DEVICES
*
PUTCHR	LBRA	WRCON
*
* CHECK FOR <ESC> FROM TERMINAL. ALSO PERFORM <LF>, <CR>
* SCREEN OUTPUT FLOW CONTROL
*
CHKCHR	LDB	HELD		GET I/O CONFIG
	BNE	CHKC1		ALREADY HELD
	LBSR	RDCON		READ TERMINAL
	CMPA	#$0A		LINE-FEED?
	BNE	CHKC3		NO, IGNORE IT
CHKC1	LBSR	GETCHR		GET KEY FROM CONSOLE
	LDB	#$FF
	CMPA	#$0A		LF?
	BEQ	CHKC2		YES, ALLOW
	CLRB			DISABLE HELD BIT
	CMPA	#$0D		CARRIAGE RETURN?
	BEQ	CHKC2		ALLOW
	CMPA	#$1B		ESCAPE?
	BNE	CHKC1		NO, IGNORE
CHKC2	STB	HELD		RESAVE I/O CONFIG BYTE
CHKC3	CMPA	#$1B		TEST FOR ESCAPE CHARACTER
	RTS
*
* STEP ONE INSTRUCTION
*
STEPDI	LDY	SAVPC		GET PC
	LDU	#DSPBUF		GET INPUT BUFFER
	LBSR	DISASS		DISPLAY
	LDX	#DSPBUF		POINT TO IT
	LBSR	WRLIN		DISPLAY
	BRA	STEPCE		AND PERFORM STEP
*
* STEP WITHOUT DISPLAYING INSTRUCTION
*
STEP	LDY	SAVPC		GET PROGRAM COUNTER
	LDU	#DSPBUF		POINT TO FREE RAM FOR DISASEMBLY OUTPUT
	LBSR	DISASS		PERFROM DISASSEMBLY
STEPCE	STY	SAVPC		SAVE NEW PC
	LDU	PTRSAV		GET POINTER BACK
	LDD	,U+		GET OPCODE
* TEST FOR LONG CONDITIONAL BRANCHES
LCBRAN	CMPA	#$10		PREFIX?
	BNE	LOBRAN		NO, GOT FOR IT
	LDB	,U		GET OPCODE
	CMPB	#$22		IN RANGE?
	BLO	LOBRAN		NO
	CMPB	#$2F		IN RANGE?
	BHI	LOBRAN		NO
	LDA	,U+		GET OPCOIDE BYTE
	LBSR	TSTCON		TEST CONDITIONAL
	BEQ	LBRAN1		YES, DO IT
	RTS	
* TEST FOR LONG BRANCHES
LOBRAN	CMPA	#$16		IS IT LBRA?
	BNE	LBRANS		NO, TRY LBSR
LBRAN1	LDD	,U++		GET OFFSET
	LEAX	D,U		PERFORM BRANCH
	BRA	SAVNPC		SAVE NEW PC
* TEST FOR LONG BRANCH TO SUB
LBRANS	CMPA	#$17		'LBSR'?
	BNE	SCOBRA		NO, TRY SHORT CONDITIONALS
	LDD	,U++		GET OFFSET
	LEAX	D,U		SET UP ADDRESS
	BRA	SAVSTK	
* TEST FOR SHORT CONDITIONAL BRANCHES
SCOBRA	CMPA	#$22		< 'BHI'?
	BLO	SHBRAN		NO, TRY SHORT BRANCHES
	CMPA	#$2F		> 'BLE'?
	BHI	SHBRAN		NO, TRY SHORT BRANCHES
	LBSR	TSTCON		SEE OF CONDITIONAL IS OK
	BEQ	SBRAN1		YES, DO IT
	RTS	
* TEST FOR SHORT BRANCHES
SHBRAN	CMPA	#$20		SHORT BRANCH?
	BNE	SBRANS		NO, TRY SHORT BRANCH TO SUB
SBRAN1	LDB	,U+		GET OFFSET
	LEAX	B,U		EMULATE JUMP
	BRA	SAVNPC		SAVE NEW PC
* TEST FOR SHORT BRANCH TO SUBROUTINE
SBRANS	CMPA	#$8D		'BSR'?
	BNE	TSTTFR		NO, TRY TRANSFER
	LDB	,U+		GET OFFSET
	LEAX	B,U		PERFORM BRANCH
SAVSTK	LDY	SAVS		GET STACK POINTER
	STU	,--Y		PUSH ADDRESS
	STY	SAVS		RESAVE
SAVNPC	STX	SAVPC		SAVE IT
	RTS	
* TEST FOR TRANSFER
TSTTFR	CMPA	#$1F		TRANSFER?
	BNE	TSTEXG		NO, TRY EXCHANGE
	BSR	LOKREG		LOOKUP REGISTER
	RTS
* LOOKUP REGISTER, AND SIMULATE IF PC XFER OR EXCHANGE
LOKREG	LDA	,U		GET POSTBYTE
	ANDA	#$0F		REMOVE HIGH REGISTER
	CMPA	#5		IS IT PC?
	BNE	LOK1		NO, IT'S OK TO EXECUTE
	LDA	,U		GET REG POSTBYTE BACK
	LSRA			SHIFT
	LSRA			HIGH REGISTER
	LSRA			TO LOW (LEAVE X 2)
LOK2	LDX	#TFREGT		POINT TO TABLE
	ANDA	#$0F		INSURE WE GET VALID REG
	LDX	A,X		GET ADDRESS OF VARIABLE
	LDD	,X		GET REGISTER VALUE
	BRA	STDPC		SAVE IT
LOK1	LEAS	2,S		SKIP LAST CALL
	LBRA	NOREXE		EXECUTE NORMAL INSTRUCTION
* TEST FOR EXCHANGE
TSTEXG	CMPA	#$1E		IS IT EXCHANGE
	BNE	TSTRTS		NO, TRY RTS
	LDY	SAVPC		GET OLD PC VALUE
	LDA	,U		GET REGISTER
	ANDA	#$F0		USE HIGH ONLY
	CMPA	#$50		IS PC FIRST?
	BNE	TSTE1		NO, SKIP
	LDA	,U		GET REG BACK
	LSLA			DOUBLE
	BSR	LOK2		GET ADDRESS OF REG TO SWAP WITH
	BRA	TSTE2		PERFORM MOVE TO PC
TSTE1	BSR	LOKREG		GET REGISTER SEE IF PC IS LOW REGISTER
TSTE2	STY	,X		SAVE PC IN REGISTER
	RTS
* TEST FOR 'RTS' INSTRUCTIONS
TSTRTS	CMPA	#$39		IS IT 'RTS'
	BNE	TPULS		NO, TRY PULS
	LDU	SAVS		POINT TO STACK
	PULU	A,B		GET DATA
	STU	SAVS		RESAVE SP
STDPC	STD	SAVPC
	RTS
* TEST FOR 'PULS' INSTRUCTION
TPULS	CMPA	#$35		PULLING FROM S?
	BNE	TPULU		NO, TRY PULU
	LDX	SAVS		GET SAVED 'S' REG
	LDY	#PULSTAB	POINT TO TABLE
	BSR	DOPUL		PERFORM PULL
	STX	SAVS		RESAVE NEW 'S' REGISTER
	RTS	
* TEST FOR A 'PULU' INSTRUCTION
TPULU	CMPA	#$37		IS IT 'PULU'?
	BNE	JSREXT		NO, TRY JSR EXTENDED
	LDX	SAVU		GET SAVED 'U'
	LDY	#PULUTAB	POINT TO TABLE
	BSR	DOPUL		PERFORM PULL
	STX	SAVU		RESAVE 'S'
	RTS	
* PERFORM PUL OPERATIONS
DOPUL	LDA	,U		GET POSTBYTE
	LDB	#4		TEST FOR FIRST FOUR BITS (8 BIT REG)
DOPUL1	DECB			DECREMENT COUNT
	LSRA			SHIFT
	BCC	DOPUL2		NOTHING, GO AGAIN
	PSHS	A,B		SAVE REGS
	TSTB			ARE WE INTO 16 BITS?
	BMI	PUL16		YES, PERFORM 16 BITS
	LDA	,X+		PULL A BYTE
	STA	[,Y++]		SAVE IN REGISTER
	BRA	DOPUL3		GO AGAIN
PUL16	LDD	,X++		GET 16 BIT VALUE
	STD	[,Y++]		SAVE IN REGISTER
DOPUL3	PULS	A,B		RESTORE
	BRA	DOPUL1		CONTINUE
DOPUL2	LEAY	2,Y		ADVANCE
	TSTA			ARE WE CONE
	BNE	DOPUL1		CONTINUE
	RTS	
* TEST FOR 'JSR' EXTENDED
JSREXT	CMPA	#$BD		IS IT EXTENDED JSR
	BNE	JMPEXT		NO, TRY JUMP EXTENDED
	BSR	DJMPEX		FAKE JUMP
	BRA	PSHPC		SAVE PC
* TEST FOR 'JMP' EXTENDED
JMPEXT	CMPA	#$7E		IS IT JMP EXTENDED?
	BNE	JSRDIR		NO, TRY JMP DIRECT
DJMPEX	LDD	,U++		GET ADDRESS
	BRA	STDPC		SAVE IT
* TEST FOR 'JSR' DIRECT
JSRDIR	CMPA	#$9D		'JSR' DIRECT PAGE?
	BNE	JMPDIR		NO, TRY JUMP
	BSR	DJMPDI		DO IT
	BRA	PSHPC		SAVE PC
* TEST FOR 'JMP' DIRECT PAGE
JMPDIR	CMPA	#$0E		IS IT JUMP DIRECT PAGE?
	BNE	JSRIND		NO, TRY JUMP INDEXED
DJMPDI	LDB	,U+		GET LOW ADDRESS
	LDA	SAVDP		GET DIRECT PAGE
	BRA	STDPC		SAVE IT
* TEST FOR 'JSR' INDEXED
JSRIND	CMPA	#$AD		IS IT 'JSR' INDEXED?
	BNE	JMPIND		NO
	BSR	DJMPIN		DO IT
PSHPC	LDX	SAVS		GET ADDRESS
	STU	,--X		SAVE
	STX	SAVS		RESAVE
	RTS	
* TEST FOR 'JMP' INDEXED
JMPIND	CMPA	#$6E		IS IT JUMP INDEXED?
	LBNE	NOREXE		NO, TRY JST EXTENDED
* FIRST POINT Y AT REGISTER INVOLVED
DJMPIN	LDA	,U+		GET POSTBYTE
	PSHS	A		SAVE IT
	ANDA	#$60		MASK OTHER CRAP
	LSRA			CONVERT
	LSRA			REGISTER
	LSRA			INTO INDEX VALUE
	LSRA			SHIFT IT OVER
	LDX	#INDTAB		POINT TO TABLE
	LDY	A,X		GET REGISTER ADDRESS
	STY	REGIND		SAVE IT
	LDY	,Y		GET REGSTER CONTENTS
	LDA	,S		GET POSTBYTE BACK
	ANDA	#$9F		MASK IT
	BMI	NOT5BO		NOT A FIVE BIT OFFSET
* FIVE BIT REGISTER OFFSET
	ANDA	#$1F		MASK FOR CRAP
	CMPA	#$10		NEGATIVE?
	BLO	SINOK		NO, IT'S OK
	ORA	#$E0		CONVERT TO NEGATIVE
SINOK	LEAX	A,Y		GET ADDRESS
	BRA	XSAVPC		SAVE IT
* TEST FOR NO OFFSET
NOT5BO	ANDA	#$EF		REMOVE INDIRECT BIT
	CMPA	#$84		NO OFFSET?
	BNE	TOFF8		NO, TRY OFFSET OF 8
	TFR	Y,X		COPY
	BRA	XSAVPC		SAVE IT
* TEST FOR EIGHT BIT OFFSET
TOFF8	CMPA	#$88		8 BIT OFSET?
	BNE	TOFF16		NO, TRY 16 BIT OFFSET
	LDB	,U+		GET OFFSET
	BRA	BSAVOF		GO FOR IT
* TEST FOR 16 BIT OFFSET
TOFF16	CMPA	#$89		16 BIT OFFSET?
	BNE	TOFFA		TRY A ACCUMULATOR OFFSET
	LDD	,U+		GET OFFSET
	LEAX	D,Y		DO IT
	BRA	XSAVPC		SAVE IT
* TEST FOR ACCA OFFSET
TOFFA	CMPA	#$86		OFFSET BY ACCA
	BNE	TOFFB		NO, TRY B
	LDB	SAVA		GET ACCA
	BRA	BSAVOF		SAVE IT
* TEST FOR ACCB OFFSET
TOFFB	CMPA	#$85		B OFFSET
	BNE	TOFFD		NO, TRY D OFFSET
	LDB	SAVB		GET B
BSAVOF	LEAX	B,Y		DO OFFSET
	BRA	XSAVPC		SAVE IT
* TEST FOR ACCD OFFSET
TOFFD	CMPA	#$8B		IS IT D OFFSET?
	BNE	TAINC1		NO, TRY AUTO INC
	LDD	SAVA		GET D ACCUMULATOR
	LEAX	D,Y		DO IT
	BRA	XSAVPC		SAVE IT
* TEST FOR AUTO INCREMENT
TAINC1	CMPA	#$80		AUTO INC BY 1?
	BNE	TAINC2		NO, TRY AUTO INC BY 2
	LEAX	,Y+		GET ADDRESS
	BRA	RSVREG		RESAVE REGISTER
* TEST FOR DOUBLE AUTO INCREMENT
TAINC2	CMPA	#$81		AUTO INC BY 1?
	BNE	TADEC1		NO, TRY AUTO DEC
	LEAX	,Y++		GET ADDRESS
	BRA	RSVREG		RESAVE REGISTER
* TEST FOR AUTO DECREMENT
TADEC1	CMPA	#$82		AUTO DEC?
	BNE	TADEC2		NO, TRY AUTO DEC BY TWO
	LEAX	,-Y		GET ADDRESS
	BRA	RSVREG		RESAVE REGISTER
* TEST FOR DOUBLE AUTO DECREMENT
TADEC2	CMPA	#$83		DOUBLE AUTO DEC
	BNE	TPCO8		NO, TRY PC OFFSET
	LEAX	,--Y		GET OFFSET
RSVREG	STY	[REGIND]	RESAVE REGISTER CONTENTS
XSAVPC	BRA	SAVXPC		SAVE NEW PC
* TEST FOR EIGHT BIT OFFSET FROM PCR
TPCO8	CMPA	#$8C		8 BIT PC RELATIVE?
	BNE	TPCO16		NO, TRY 16 BIT PC RELATIVE
	LDB	,U+		GET BYTE
	LEAX	B,U		OFFSET IT
	BRA	SAVXPC		RESAVE PC
* TEST FOR 16 BIT OFFSET FROM PCR
TPCO16	CMPA	#$8D		16 BIT OFFSET
	BNE	TEIND		NO, TRY EXTENDED INDIRECT
	LDD	,U++		GET VALUE
	LEAX	D,U		POINT TO NEW LOCATION
	BRA	SAVXPC		RESAVE
* EXTENDED ADDRESSING VIA INDEXED POSTBYTE
TEIND	LDX	,U++		GET ADDRESS
* SAVE CALCULATED ADDRESS IN REGISTER, BUT FIRST CHECK FOR INDIRECTION
SAVXPC	PULS	A		RESTORE POSTBYTE
	BITA	#$10		INDIRECT?
	BEQ	NINXIN		NOT INDIRECT
	LDX	,X		PERFORM A LEVEL OF INDIRECTION
NINXIN	STX	SAVPC		SAVE IT
	RTS	
* NORMAL EXECUTABLE INSTRUCTION, COPY IT INTO OUR RAM, THEN EXECUTE IT
NOREXE	LEAU	-1,U		BACKUP TO INSTRUCTION
	LDX	#INSRAM		POINT TO RAM FOR INSTRUCTION
* COPY INSTRUCTION INTO RAM
NORE1	CMPU	SAVPC		ARE WE THERE
	BHS	NORE2		END OF INSTRUCTION
	LDA	,U+		GET DATA
	STA	,X+		SAVE IN RAM
	BRA	NORE1		CONTINUE
* INSERT A JUMP AFTER IT
NORE2	LDA	#$7E		GET 'JMP' EXTENDED INSTRUCTION
	STA	,X+		SAVE IT
	LDD	#NORE3		POINT AT ADDRESS TO JUMP TO
	STD	,X		SAVE IT
	STS	REGIND		SAVE SP
	LDS	SAVS		RESTORE STACK POINTER
	LDA	SAVCC		GET CC
	LDB	SAVDP		GET DP
	PSHS	A,B		SAVE CC AND DP
	LDD	SAVA		RESTORE A, B
	LDX	SAVX		RESTORE X
	LDY	SAVY		RESTORE Y
	LDU	SAVU		RESTORE U
	PULS	CC,DP		RESTORE CC AND DP
	JMP	INSRAM		EXECUTE INSTRUCTION
* INSTRUCTION SHOULD RETURN TO HERE
NORE3	PSHS	CC,DP		SAVE REGS
	STD	SAVA		SAVE REGS
	STX	SAVX		SAVE X
	STY	SAVY		SAVE Y
	STU	SAVU		SAVE U
	PULS	A,B		GET REGS BACK
	STA	SAVCC		SAVE CC
	STB	SAVDP		SAVE DP
	STS	SAVS		SAVE STACK POINTER
	LDS	REGIND		RESTORE OUR STACK
	RTS	
*
* SUBROUTINE TO EVALUATE CONDITIONAL BRANCH OPCODES, AND DETERMINE
* IF THEY ARE TO BE EXECUTED
*
TSTCON	LDB	#3		TEST FOR THREE CONDITIONALS
	CMPA	#$2F		IS IT 'BLE'?
	BNE	TSTC0		NO, ITS NORMAL
	LDB	#6		HANDLE WRETCHED 'BLE' CASE
TSTC0	SUBA	#$22		CONVERT OPCODE TO SIMPLE INDEX
	ASLA			ROTATE.
	ASLA			TWICE FOR FOUR BYTE ENTRIES
	LDX	#CONTAB		POINT TO TABLE
	LEAX	A,X		ADVANCE TO TABLE ENTRY
	LDA	SAVCC		GET CONDITION CODES
	ANDA	,X+		MASK OUT NON-APPLICABLE ONES
TSTC1	CMPA	,X+		DOES IT MATCH?
	BEQ	TSTC2		IT'S OK
	DECB			REDUCE COUNT
	BNE	TSTC1		CONTINUE
	LDA	#255		INDICATE CONDITIONAL NOT MET
	RTS	
TSTC2	CLRA			INDICATE CONDITIONAL MET
	RTS	
*
* DISASSEMBLE OPCODE POINTED TO BY Y. PLACE IN OUTPUT BUFFER POINTED TO BY U
*
DISASS	STY	PTRSAV		SAVE INSTRUCTION POINTER
	PSHS	U		SAVE INST POINTER
	LDD	#$2000+26	GET SPACE+NUMBER OF BYTES TO CLEAR
DISA1	STA	,U+		SET A SPACE
	DECB			REDUCE COUNT
	BNE	DISA1		CONTINUE
	LDX	#OPTAB1		POINT TO GENERAL OPCODE TABLE
	LDA	,Y		GET DATA BYTE
	CMPA	#$10		PREFIX BYTE?
	BEQ	SETOP2		NEW TABLE
	CMPA	#$11		OTHER PREFIX BYTE
	BNE	OPFIND		NO, IT'S OK
	LDX	#OPTAB3		POINT TO THIRD TABLE
	BRA	OPFNXT		OK
SETOP2	LDX	#OPTAB2		POINT TO SECOND OPERAND TABLE
OPFNXT	LEAY	1,Y		SKIP PREFIX BYTE
* LOOK FOR OPCODE IN TABLE
OPFIND	LDA	,X+		GET BYTE FROM TABLE
	CMPA	,Y		IS THIS IT?
	BEQ	FNDOPC		FOUND IT
	CMPA	#$CF		END OF TABLE?
	BEQ	BADOPC		IF SO, FAKE AN OPCODE
	LEAX	2,X		ADVANCE
	BRA	OPFIND		KEEP LOOKING
BADOPC	LDY	PTRSAV		INSURE WE ARE AT BEGINNING
* LOCATED OPCODE, GENERATE STRING
FNDOPC	LEAY	1,Y		SKIP TO POSTBYTE
	LDA	,X+		GET DATA
	STA	INSTYP		SAVE FOR LATER
	LDB	,X		GET INSTRUCTION NUMBER
	LDA	#4		FOUR BYTES/ENTRY
	MUL			CALCULATE ENTRY OFFSET
	LDX	#ITABLE		POINT TO INSTRUCTION TABLE
	LEAX	D,X		ADVANCE TO IT
	LDB	#4		SIZE OF INSTRIUCTION FIELD
FNDO1	LDA	,X+		GET CHAR
	STA	,U+		SAVE IN OUTPUT
	DECB			MOVE FOUR CHARACTERS
	BNE	FNDO1		CONTINUE
FNDO2	LDA	INSTYP		GET TYPE BITS BACK
	ANDA	#$0F		REMOVE CRAP
	LBEQ	ENDIS		NO OPERANDS
* INSERT SPACES FOR OPERAND
	LDB	#' '		GET A SPACE
	STB	,U+		SAVE IN OUTPUT
	STB	,U+		SAVE IN OUTPUT
	DECA			IS 8 BIT IT IMMEDIATE?
	BNE	IMM16		NO, TRY 16 BIT IMMEDIATE
* EIGHT BIT IMMEDIATE ADDRESSING OPERAND
IMM8	LDA	#'#'		INDICATE IMMEDIATE
	STA	,U+		SAVE IT
	BRA	OP8		QUIT
* SIXTEEN BIT IMMEDIATE ADDRESSING
IMM16	DECA			IS THIS IT?
	BNE	DIRECT		NO, TRY DIRECT
	LDA	#'#'		INDICATE IMMEDIATE
	STA	,U+		SAVE IT
	BRA	OP16		16 BIT OPERAND
* DIRECT PAGE ADDRESSING
DIRECT	DECA			IS THIS IT?
	BNE	EXTEND		NO, TRY EXTENDED
	LDA	#'<'		INDICATE DIRECT
	STA	,U+		SAVE IT
OP8	LDA	,Y+		GET OPERAND BYTE
	LBSR	WRHEXB		OUTPUT
	BRA	ENDIS1		END GO HOME
* EXTENDED ADDRESSING
EXTEND	DECA			IS THIS IT?
	BNE	INDEX		NO, TRY INDEXED
OP16	LDD	,Y++		GET OPCODES
	LBSR	WRHEXW		OUTPUT WORD
ENDIS1	LBRA	ENDIS		GO HOME
* INDEXED ADDRESSING MODES
INDEX	DECA			IS IT INDEXED?
	LBNE	PSHPUL		NO, TRY PUSH OR PUL
	LDA	,Y+		GET POST BYTE
	STA	POSBYT		SAVE FOR LATER
* TEST FOR FIVE BIT OFFSET
	BMI	NO5BO		NOT A FIVE BIT OFFSET
	ANDA	#$1F		CONVERT TO POSTBYTE
	BRA	EVLX1		INSERT REGISTER AND CONTINUE
* TEST FOR INDIRECT MODE
NO5BO	BITA	#$10		TEST FOR INDIRECT
	BEQ	NOIND		NOT INDIRECT
	LDB	#'['		GET OPENING
	STB	,U+		SAVE IN OUTPUT
* TEST FOR NO OFFSET
NOIND	ANDA	#$8F		REMOVE REGS AND INDIRECT BIT
	CMPA	#$84		NO OFFSET?
	BEQ	INSR1		INSERT REGISTER AND EXIT
* TEST FOR EIGHT BIT OFFSET
	CMPA	#$88		EIGHT BIT OFFSET
	BNE	EVL1		NO, TRY NEXT
	LDA	,Y+		GET BYTE OFFSET
EVLX1	LBSR	WRHEXB		OUTPUT
	BRA	INSR1		CONTINUE
* TEST FOR 16 BIT OFFSET
EVL1	CMPA	#$89		16 BIT OFSET?
	BNE	EVL2		NO, TRY NEXT
	LDD	,Y++		GET OPERAND
	LBSR	WRHEXW		OUTPUT
	BRA	INSR1		INSERT REGISTER
* TEST FOR A ACCUMULATOR OFFSET
EVL2	CMPA	#$86		IS IT 'A' OFFSET?
	BNE	EVL3		NO, TRY NEXT
	LDA	#'A'		GET ACCA
	BRA	SAIREG		GO HOME
* TEST FOR B ACCUMULATOR OFFSET
EVL3	CMPA	#$85		IS IT 'B' OFFSET?
	BNE	EVL4		NO, TRY NEXT
	LDA	#'B'		GET B
	BRA	SAIREG		GO HOME
* TEST FRO 'D' ACCUMULATOR OFFSET
EVL4	CMPA	#$8B		D OFFSET?
	BNE	EVL5		NO, TRY NEXT
	LDA	#'D'		GET D REGISTER
SAIREG	STA	,U+		SAVE IT
INSR1	BRA	INSREG	
* TEST FOR EXTENDED INDIRECT
EVL5	CMPA	#$8F		EXTENDED INDIRECT?
	BNE	EVL6		NO, TRY NEXT
	LDD	,Y++		GET OFFSET
	LBSR	WRHEXW		OUTPUT
	BRA	EVLFIN		AND CONTINUE
* TEST FOR PC OFFSET, 8 BIT
EVL6	CMPA	#$8C		EIGHT BIT PC OFFSET?
	BNE	EVL7		NO, TRY NEXT
	LDA	,Y+		GET OFFSET
	LBSR	WRHEXB		OUTPUT
	BRA	WRPCRG		OUTPUT PC REGISTER
* TEST FOR PC OFFSET, 16 BIT
EVL7	CMPA	#$8D		PC OFFSET?
	BNE	INSREG		NO, INSERT REGISTER
	LDD	,Y++		GET OFFSET
	LBSR	WRHEXW		OUTPUT
WRPCRG	LDX	#PCRG		POINT TO STRING
WRPR1	LDA	,X+		GET CHAR
	STA	,U+		SAVE
	CMPA	#'R'		END?
	BNE	WRPR1		NO, CONTINUE
	BRA	EVLFIN		END IT NOW
* INSERT REGISTER BITS
INSREG	LDA	#','		GET COMMA
	STA	,U+		SAVE IT
	LDA	POSBYT		GET POSTBYTE
	LDB	#'-'		GET MINUS
	ANDA	#$8F		REMOVE CRAP
	CMPA	#$82		DECREMENT BY ONE?
	BEQ	DEC1		DECREMENT BY ONE
	CMPA	#$83		DECREMENT BY TWO?
	BNE	NODEC		NO, DON'T DEC
	STB	,U+		SAVE
DEC1	STB	,U+		AGAIN
NODEC	LDA	POSBYT		GET POSTBYTE
	LSRA			SHIFT
	LSRA			REGISTER
	LSRA			BITS
	LSRA			INTO
	LSRA			BOTTOM
	LDB	#'X'		GET 'X'
	ANDA	#$03		REMOVE CRAP
	BEQ	EVLEND		ITS 'X'
	LDB	#'Y'		GET 'Y'
	DECA			TEST FOR 'Y'
	BEQ	EVLEND		YES
	LDB	#'U'		GET 'U'
	DECA			TEST
	BEQ	EVLEND		ITS 'U'
	LDB	#'S'		MUST BE 'S'
EVLEND	STB	,U+		SAVE IN OUTPUT
EVLFIN	LDA	POSBYT		GET POSTBYTE
	LDB	#'+'		GET PLUS
	ANDA	#$8F		GET TYPE
	CMPA	#$80		IS IT INC BY ONE
	BEQ	INC1		IF SO, WE HAVE IT
	CMPA	#$81		INC BY TWO?
	BNE	NOINC		NO INCREMENT
	STB	,U+		SAVE ONE
INC1	STB	,U+		SAVE TWO
NOINC	LDA	POSBYT		GET POSTBYTE
	BPL	NOIND1		FIVE BIT OFFSET
	BITA	#$10		INDIRECT?
	BEQ	NOIND1		NO INDIRECT
	LDA	#']'		CLOSING BRACE
	STA	,U+		SAVE IT
NOIND1	LBRA	ENDIS		END IT
* PULS OR PULL OPCODES
PSHPUL	DECA			IS IT PUSH OR PULL?
	BNE	TFREXG		NO, TRY TRANSFER OR EXCHANGE
	LDA	,Y+		GET POSTBYTE
	LDX	#PSHTAB		GET 'CC'
PSH1	LSRA			SHIFT OUT BITS
	BCC	PSHNXT		SKIP THIS ONE
	PSHS	A,B		SAVE REGS
	LDD	,X++		GET DATA
	CMPA	#'U'		SAVEING U REGISTER
	BNE	PSH4		NO, IT'S OK
	TST	INSTYP		SPECIAL CASE
	BPL	PSH4		OK
	LDA	#'S'		CONVERT
PSH4	STA	,U+		SAVE IT
	TSTB			MORE?
	BEQ	PSH2		NO, SKIP IT
	STB	,U+		SAVE
PSH2	PULS	A,B		RESTORE REGS
	TSTA			MORE BITS?
	BEQ	PSH3		NO, QUIT
	PSHS	A		RESAVE
	LDA	#','		GET COMMA
	STA	,U+		SAVE
	PULS	A		GET IT BACK
	BRA	PSH1		CONTINUE
PSHNXT	LEAX	2,X		ADVANCE
	TSTA			ARE WE OK
	BNE	PSH1		KEEP TRYING
PSH3	LBRA	ENDIS		DONE
* TRANSFER AND EXCHANGE POSTBYTE OPCODES
TFREXG	DECA			TRANSFER OR EXCHANGE?
	BNE	SBRAN		TRY SHORT BRANCH
	LDA	,Y		GET POSTBYTE
	LSRA			SHIFT
	LSRA			INTO
	LSRA			LOW
	LSRA			NIBBLE
	BSR	TFRREG		GET REGISTER
	LDA	#','		SEPERATOR
	STA	,U+		SAVE
	LDA	,Y+		GET POSTBYTE AGAIN
	BSR	TFRREG		PLACE IT
	LBRA	ENDIS		GO HOME
* CALCULATE TRANSFER REGISTER
TFRREG	ANDA	#$0F		REMOVE HIGH CRAP
	ASLA			MULTIPLY BY TWO
	LDX	#REGTAB		POINT TO TABLE
	LDD	A,X		GET REGISTER VALUE
	STA	,U+		SAVE IT
	TSTB			SECOND BYTE?
	BEQ	TFRET		NO, SKIP IT
	STB	,U+		SAVE IT
TFRET	RTS	
* SHORT BRANCH
SBRAN	DECA			SHORT BRANCH
	BNE	LBRAN		NO, TRY LONG BRANCH
	LDB	,Y+		GET OPERATOR
	LEAX	B,Y		GET NEW ADDRESS
	TFR	X,D		COPY
	BRA	SAVADR		FINISH
* LONG BRANCH
LBRAN	LDD	,Y++		GET OPERAND
	PSHS	Y		SAVE Y
	ADDD	,S++		ADD OFFSET TO REG
SAVADR	LBSR	WRHEXW		OUTPUT WORD.    
ENDIS	LDA	#$0D		GET CR
	STA	,U		SAVE IT
* INSERT ADDRESS/BYTE DATA
	LDU	,S		RESTORE U REGISTER
	PSHS	Y		SAVE POINTER TO END
	LDX	PTRSAV		POINT TO STARTING ADDRESS
	TFR	X,D		COPY
	LBSR	WRHEX		OUTPUT
	TFR	B,A		COPY
	LBSR	WRHEX		OUTPUT
	CLRB			START WITH ZERO
END1	CMPX	,S		ARE WE AT END?
	BHS	END2		IF SO, QUIT
	INCB			ADVANCE
	LEAU	1,U		ADVANCE
	LDA	,X+		GET BYTE
	LBSR	WRHEX		OUTPUT
	BRA	END1		CONTINUE
END2	LEAS	2,S		RESTORE STACK
	LDU	,S		RESTORE U REGISTER
	LEAU	20,U		ADVANCE TO TEXT FIELD
	LDX	PTRSAV		GET POINTER BACK
END3	DECB			REDUCE COUNT
	BMI	END4		CONTINUE
	LDA	,X+		GO IT AGAIN
	CMPA	#' '		< SPACE?
	BLO	END5		YES
	CMPA	#$7F		> 7F?
	BLO	END6		OK
END5	LDA	#'.'		CONVERT TO DOT
END6	STA	,U+		SAVE
	BRA	END3	
END4	PULS	U,PC		GO HOME
*
* SUBROUTINES
*
WRHEXB	PSHS	A		SAVE IT
	LDA	#'$'		INDICATE HEX
	STA	,U+		SAVE
	BRA	WRHEX1		CONTINUE
WRHEXW	PSHS	B		SAVE B
	LDB	#'$'		INDICATE HEX
	STB	,U+		SAVE IT
	BSR	WRHEX		OUTPUT
WRHEX1	PULS	A		RESTORE
WRHEX	PSHS	A		SAVE IT
	LSRA			SHIFT
	LSRA			HIGH BYTE
	LSRA			INTO
	LSRA			LOW FOR OUTPUT
	BSR	WRHEXN		OUTPUT NIBBLE
	PULS	A		RETORE
WRHEXN	ANDA	#$0F		REMOVE CRAP
	ADDA	#$30		CONVERT
	CMPA	#$39		OK?
	BLS	WRNOK		OK
	ADDA	#7		CONVERT
WRNOK	STA	,U+		SAVE IT
	RTS	
*
* SWI HANDLER
*
SWIHND	LDY	#BRKTAB		POINT TO BREAKPOINT TABLE
	LDX	10,S		GET STORED PC
	LEAX	-1,X		BACKUP TO BREAKPOINT ADDRESS
	LDB	#8		CHECK EIGHT BREAKPOINTS
SWIHN1	CMPX	,Y		IS THIS IT?
	BEQ	SWIHN2		YES
	LEAY	3,Y		SKIP OPCODE
	DECB			REDUCE COUNT
	BNE	SWIHN1		CONTINUE
	LDB	2,S		RESTORE B
	LDX	4,S		RESTORE X
	LDY	6,S		RESTORE Y
	JMP	[SWIADR]	NOT A BREAKPOINT, EXECUTE SWI HANDLER
SWIHN2	STB	INSTYP		SAVE BREAKPOINT NUMBER
	LDX	#SAVCC		POINT TO START OF SAVED REGS
	LDB	#10		MOVE 10
SWIHN25	LDA	,S+		GET BYTE
	STA	,X+		SAVE
	DECB			DECREMENT COUNT
	BNE	SWIHN25		DO THEM ALL
	PULS	X		GET PC
	LEAX	-1,X		SET BACK TO REAL PC
	STX	SAVPC		SAVED PC
	STS	SAVS		SAVE STACK POINTER
	LBSR	WRMSG		DISPLAY MESSAGE
	FCCZ	'Breakpoint #'
	LDA	#$38		GET NUMBER, PLUS ASCII CONVERT
	SUBA	INSTYP		CONVERT TO PROPER DIGIT
	LBSR	PUTCHR		DISPLAY
	LBSR	LFCR		NEW LINE
	TST	STPFLG		TO WE DISPLAY
	BNE	BRKRES		NO
	LBSR	DISREG		DISPLAY
BRKRES	LDX	#BRKTAB		POINT TO BREAKPOINT TABLE
	LDB	#8		DO IT EIGHT TIMES
SWIHN3	LDY	,X++		GET REG
	BEQ	SWIHN4		NO BRK, NEXT
	LDA	,X		GET OPCODE
	STA	,Y		REPLACE IN RAM
SWIHN4	LEAX	1,X		SKIP OPCODE
	DECB			REDUCE COUNT
	BNE	SWIHN3		GO AGAIN
	LBRA	MAIN		DO PROMPT
* CONSTANTS
PCRG	FCC	',PCR'	
* TRANSFER/EXCHANGE REGISTER TABLE
REGTAB	FCCZ	'D'		0
	FCCZ	'X'		1
	FCCZ	'Y'		2
	FCCZ	'U'		3
	FCCZ	'S'		4
	FCC	'PC'		5
	FCCZ	'?'		6
	FCCZ	'?'		7
	FCCZ	'A'		8
	FCCZ	'B'		9
	FCC	'CC'		A
	FCC	'DP'		B
	FCCZ	'?'		C
	FCCZ	'?'		D
	FCCZ	'?'		E
	FCCZ	'?'		F
* PUSH/PULL REGISTER TABLE
PSHTAB	FCC	'CC'	
	FCCZ	'A'	
	FCCZ	'B'	
	FCC	'DP'	
	FCCZ	'X'	
	FCCZ	'Y'	
	FCCZ	'U'	
	FCCZ	'PC'	
*
* OPCODE TABLE, OPCODE BYTE, TYPE BYTE, TEXT BYTE
*
OPTAB1	FCB	$86,1,1		'LDA' INSTRUCTIONS
	FCB	$96,3,1	
	FCB	$A6,5,1	
	FCB	$B6,4,1	
	FCB	$C6,1,2		'LDB' INSTRUCTIONS
	FCB	$D6,3,2	
	FCB	$E6,5,2	
	FCB	$F6,4,2	
	FCB	$CC,2,3		'LDD' INSTRUCTIONS
	FCB	$DC,3,3	
	FCB	$EC,5,3	
	FCB	$FC,4,3
	FCB	$CE,2,4		'LDU' INSTRUCTIONS
	FCB	$DE,3,4	
	FCB	$EE,5,4	
	FCB	$FE,4,4	
	FCB	$8E,2,5		'LDX' INSTRUCTIONS
	FCB	$9E,3,5	
	FCB	$AE,5,5	
	FCB	$BE,4,5	
	FCB	$97,3,6		'STA' INSTRUCTINOS
	FCB	$A7,5,6	
	FCB	$B7,4,6	
	FCB	$D7,3,7		'STB' INSTRUCTIONS
	FCB	$E7,5,7	
	FCB	$F7,4,7	
	FCB	$DD,3,8		'STD' INSTRUCTIONS
	FCB	$ED,5,8	
	FCB	$FD,4,8	
	FCB	$DF,3,9		'STU' INSTRUCTIONS
	FCB	$EF,5,9	
	FCB	$FF,4,9	
	FCB	$9F,3,10	'STX' INSTRUCTIONS
	FCB	$AF,5,10
	FCB	$BF,4,10
	FCB	$3A,0,11	'ABX'
	FCB	$89,1,12	'ADCA'
	FCB	$99,3,12
	FCB	$A9,5,12
	FCB	$B9,4,12
	FCB	$C9,1,13	'ADCB'
	FCB	$D9,3,13
	FCB	$E9,5,13
	FCB	$F9,4,13
	FCB	$8B,1,14	'ADDA'
	FCB	$9B,3,14
	FCB	$AB,5,14
	FCB	$BB,4,14
	FCB	$CB,1,15	'ADDB'
	FCB	$DB,3,15
	FCB	$EB,5,15
	FCB	$FB,4,15
	FCB	$C3,2,16	'ADDD'
	FCB	$D3,3,16
	FCB	$E3,5,16
	FCB	$F3,4,16
	FCB	$48,0,17	'ASLA'
	FCB	$58,0,18	'ASLB'
	FCB	$08,3,19	'ASL'
	FCB	$68,5,19
	FCB	$78,4,19
	FCB	$47,0,20	'ASRA'
	FCB	$57,0,21	'ASRB'
	FCB	$07,3,22	'ASR'
	FCB	$67,5,22
	FCB	$77,4,22
	FCB	$85,1,23	'BITA'
	FCB	$95,3,23
	FCB	$A5,5,23
	FCB	$B5,4,23
	FCB	$C5,1,24	'BITB'
	FCB	$D5,3,24
	FCB	$E5,5,24
	FCB	$F5,4,24
	FCB	$4F,0,25	'CLRA'
	FCB	$5F,0,26	'CLRB'
	FCB	$0F,3,27	'CLR'
	FCB	$6F,5,27
	FCB	$7F,4,27
	FCB	$81,1,28	'CMPA'
	FCB	$91,3,28
	FCB	$A1,5,28
	FCB	$B1,4,28
	FCB	$C1,1,29	'CMPB'
	FCB	$D1,3,29
	FCB	$E1,5,29
	FCB	$F1,4,29
	FCB	$8C,2,30	'CMPX'
	FCB	$9C,3,30
	FCB	$AC,5,30
	FCB	$BC,4,30
	FCB	$43,0,31	'COMA'
	FCB	$53,0,32	'COMB'
	FCB	$03,3,33	'COM'
	FCB	$63,5,33
	FCB	$73,4,33
	FCB	$3C,1,34	'CWAI'
	FCB	$19,0,35	'DAA'
	FCB	$4A,0,36	'DECA'
	FCB	$5A,0,37	'DECB'
	FCB	$0A,3,38	'DEC'
	FCB	$6A,5,38
	FCB	$7A,4,38
	FCB	$88,1,39	'EORA'
	FCB	$98,3,39
	FCB	$A8,5,39
	FCB	$B8,4,39
	FCB	$C8,1,40	'EORB'
	FCB	$D8,3,40
	FCB	$E8,5,40
	FCB	$F8,4,40
	FCB	$1E,7,41	'EXG'
	FCB	$1F,7,42	'TFR'
	FCB	$34,6,43	'PSHS'
	FCB	$36,$86,44	'PSHU'
	FCB	$35,6,45	'PULS'
	FCB	$37,$86,46	'PULU'
	FCB	$4C,0,47	'INCA'
	FCB	$5C,0,48	'INCB'
	FCB	$0C,3,49	'INC'
	FCB	$6C,5,49
	FCB	$7C,4,49
	FCB	$0E,3,50	'JMP'
	FCB	$6E,5,50
	FCB	$7E,4,50
	FCB	$9D,3,51	'JSR'
	FCB	$AD,5,51
	FCB	$BD,4,51
	FCB	$32,5,52	'LEAS'
	FCB	$33,5,53	'LEAU'
	FCB	$30,5,54	'LEAX'
	FCB	$31,5,55	'LEAY'
	FCB	$44,0,56	'LSRA'
	FCB	$54,0,57	'LSRB'
	FCB	$04,3,58	'LSR'
	FCB	$64,5,58
	FCB	$74,4,58
	FCB	$3D,0,59	'MUL'
	FCB	$40,0,60	'NEGA'
	FCB	$50,0,61	'NEGB'
	FCB	$00,3,62	'NEG'
	FCB	$60,5,62
	FCB	$70,4,62
	FCB	$12,0,63	'NOP'
	FCB	$8A,1,64	'ORA'
	FCB	$9A,3,64
	FCB	$AA,5,64
	FCB	$BA,4,64
	FCB	$CA,1,65	'ORB'
	FCB	$DA,3,65
	FCB	$EA,5,65
	FCB	$FA,4,65
	FCB	$1A,1,66	'ORCC'
	FCB	$84,1,67	'ANDA'
	FCB	$94,3,67
	FCB	$A4,5,67
	FCB	$B4,4,67
	FCB	$C4,1,68	'ANDB'
	FCB	$D4,3,68
	FCB	$E4,5,68
	FCB	$F4,4,68
	FCB	$1C,1,69	'ANDCC'
	FCB	$49,0,70	'ROLA'
	FCB	$59,0,71	'ROLB'
	FCB	$09,3,72	'ROL'
	FCB	$69,5,72
	FCB	$79,4,72
	FCB	$46,0,73	'RORA'
	FCB	$56,0,74	'RORB'
	FCB	$06,3,75	'ROR'
	FCB	$66,5,75
	FCB	$76,4,75
	FCB	$3B,0,76	'RTI'
	FCB	$39,0,77	'RTS'
	FCB	$82,1,78	'SBCA'
	FCB	$92,3,78
	FCB	$A2,5,78
	FCB	$B2,4,78
	FCB	$C2,1,79	'SBCB'
	FCB	$D2,3,79
	FCB	$E2,5,79
	FCB	$F2,4,79
	FCB	$1D,0,80
	FCB	$80,1,81	'SUBA'
	FCB	$90,3,81
	FCB	$A0,5,81
	FCB	$B0,4,81
	FCB	$C0,1,82	'SUBB'
	FCB	$D0,3,82
	FCB	$E0,5,82
	FCB	$F0,4,82
	FCB	$83,2,83	'SUBD'
	FCB	$93,3,83
	FCB	$A3,5,83
	FCB	$B3,4,83
	FCB	$3F,1,84	'SWI' (SSR INTERFACE)
	FCB	$13,0,85	'SYNC'
	FCB	$4D,0,86	'TSTA'
	FCB	$5D,0,87	'TSTB'
	FCB	$0D,3,88	'TST'
	FCB	$6D,5,88
	FCB	$7D,4,88
	FCB	$16,9,99	'LBRA'
	FCB	$17,9,100	'LBSR'
	FCB	$20,8,101	'BRA'
	FCB	$21,8,102	'BRN'
	FCB	$22,8,103	'BHI'
	FCB	$23,8,104	'BLS'
	FCB	$24,8,105	'BCC'
	FCB	$25,8,106	'BCS'
	FCB	$26,8,107	'BNE'
	FCB	$27,8,108	'BEQ'
	FCB	$28,8,109	'BVC'
	FCB	$29,8,110	'BVS'
	FCB	$2A,8,111	'BPL'
	FCB	$2B,8,112	'BMI'
	FCB	$2C,8,113	'BGE'
	FCB	$2D,8,114	'BLT'
	FCB	$2E,8,115	'BGT'
	FCB	$2F,8,116	'BLE'
	FCB	$8D,8,132	'BSR'
	FCB	$CF,0,0		'FCB', UNKNOWN OPCODE
* OPERAND TABLE NUMBER TWO, $10 PREFIX INSTRUCTIONS
OPTAB2	FCB	$83,2,89	'CMPD'
	FCB	$93,3,89
	FCB	$A3,5,89
	FCB	$B3,4,89
	FCB	$8C,2,90	'CMPY'
	FCB	$9C,3,90
	FCB	$AC,5,90
	FCB	$BC,4,90
	FCB	$CE,2,91	'LDS'
	FCB	$DE,3,91
	FCB	$EE,5,91
	FCB	$FE,4,91
	FCB	$8E,2,92	'LDY'
	FCB	$9E,3,92
	FCB	$AE,5,92
	FCB	$BE,4,92
	FCB	$DF,3,93	'STS'
	FCB	$EF,5,93
	FCB	$FF,4,93
	FCB	$9F,3,94	'STY'
	FCB	$AF,5,94
	FCB	$BF,4,94
	FCB	$3F,0,95	'SWI2'
	FCB	$21,9,117	'LBRN'
	FCB	$22,9,118	'LBHI'
	FCB	$23,9,119	'LBLS'
	FCB	$24,9,120	'LBCC'
	FCB	$25,9,121	'LBCS'
	FCB	$26,9,122	'LBNE'
	FCB	$27,9,123	'LBEQ'
	FCB	$28,9,124	'LBVC'
	FCB	$29,9,125	'LBVS'
	FCB	$2A,9,126	'LBPL'
	FCB	$2B,9,127	'LBMI'
	FCB	$2C,9,128	'LBGE'
	FCB	$2D,9,129	'LBLT'
	FCB	$2E,9,130	'LBGT'
	FCB	$2F,9,131	'LBLE'
	FCB	$CF,1,0	
* OPERAND TABLE #3, $11 PREFIXES
OPTAB3	FCB	$8C,2,96	'CMPS'
	FCB	$9C,3,96
	FCB	$AC,5,96
	FCB	$BC,4,96
	FCB	$83,2,97	'CMPU'
	FCB	$93,3,97
	FCB	$A3,5,97
	FCB	$B3,4,97
	FCB	$3F,0,98	'SWI3'
* INSTRUCTION TEXT TABLE
ITABLE	FCC	'FCB '		0
	FCC	'LDA '		1
	FCC	'LDB '		2
	FCC	'LDD '		3
	FCC	'LDU '		4
	FCC	'LDX '		5
	FCC	'STA '		6
	FCC	'STB '		7
	FCC	'STD '		8
	FCC	'STU '		9
	FCC	'STX '		10
	FCC	'ABX '		11
	FCC	'ADCA'		12
	FCC	'ADCB'		13
	FCC	'ADDA'		14
	FCC	'ADDB'		15
	FCC	'ADDD'		16
	FCC	'ASLA'		17
	FCC	'ASLB'		18
	FCC	'ASL '		19
	FCC	'ASRA'		20
	FCC	'ASRB'		21
	FCC	'ASR '		22
	FCC	'BITA'		23
	FCC	'BITB'		24
	FCC	'CLRA'		25
	FCC	'CLRB'		26
	FCC	'CLR '		27
	FCC	'CMPA'		28
	FCC	'CMPB'		29
	FCC	'CMPX'		30
	FCC	'COMA'		31
	FCC	'COMB'		32
	FCC	'COM '		33
	FCC	'CWAI'		34
	FCC	'DAA '		35
	FCC	'DECA'		36
	FCC	'DECB'		37
	FCC	'DEC '		38
	FCC	'EORA'		39
	FCC	'EORB'		40
	FCC	'EXG '		41
	FCC	'TFR '		42
	FCC	'PSHS'		43
	FCC	'PSHU'		44
	FCC	'PULS'		45
	FCC	'PULU'		46
	FCC	'INCA'		47
	FCC	'INCB'		48
	FCC	'INC '		49
	FCC	'JMP '		50
	FCC	'JSR '		51
	FCC	'LEAS'		52
	FCC	'LEAU'		53
	FCC	'LEAX'		54
	FCC	'LEAY'		55
	FCC	'LSRA'		56
	FCC	'LSRB'		57
	FCC	'LSR '		58
	FCC	'MUL '		59
	FCC	'NEGA'		60
	FCC	'NEGB'		61
	FCC	'NEG '		62
	FCC	'NOP '		63
	FCC	'ORA '		64
	FCC	'ORB '		65
	FCC	'ORCC'		66
	FCC	'ANDA'		67
	FCC	'ANDB'		68
	FCC	'ANDC'		69
	FCC	'ROLA'		70
	FCC	'ROLB'		71
	FCC	'ROL '		72
	FCC	'RORA'		73
	FCC	'RORB'		74
	FCC	'ROR '		75
	FCC	'RTI '		76
	FCC	'RTS '		77
	FCC	'SBCA'		78
	FCC	'SBCB'		79
	FCC	'SEX '		80
	FCC	'SUBA'		81
	FCC	'SUBB'		82
	FCC	'SUBD'		83
	FCC	'SSR '		84
	FCC	'SYNC'		85
	FCC	'TSTA'		86
	FCC	'TSTB'		87
	FCC	'TST '		88
	FCC	'CMPD'		89
	FCC	'CMPY'		90
	FCC	'LDS '		91
	FCC	'LDY '		92
	FCC	'STS '		93
	FCC	'STY '		94
	FCC	'SWI2'		95
	FCC	'CMPS'		96
	FCC	'CMPU'		97
	FCC	'SWI3'		98
	FCC	'LBRA'		99
	FCC	'LBSR'		100
	FCC	'BRA '		101
	FCC	'BRN '		102
	FCC	'BHI '		103
	FCC	'BLS '		104
	FCC	'BCC '		105
	FCC	'BCS '		106
	FCC	'BNE '		107
	FCC	'BEQ '		108
	FCC	'BVC '		109
	FCC	'BVS '		110
	FCC	'BPL '		111
	FCC	'BMI '		112
	FCC	'BGE '		113
	FCC	'BLT '		114
	FCC	'BGT '		115
	FCC	'BLE '		116
	FCC	'LBRN'		117
	FCC	'LBHI'		118
	FCC	'LBLS'		119
	FCC	'LBCC'		120
	FCC	'LBCS'		121
	FCC	'LBNE'		122
	FCC	'LBEQ'		123
	FCC	'LBVC'		124
	FCC	'LBVS'		125
	FCC	'LBPL'		126
	FCC	'LBMI'		127
	FCC	'LBGE'		128
	FCC	'LBLT'		129
	FCC	'LBGT'		130
	FCC	'LBLE'		131
	FCC	'BSR '		132
*
* CONDITIONAL TABLE, FIRST BYTE IS MASK, NEXT THREE BYTES ARE POSSIBLE
* BIT SETTINGS
*
CONTAB	FCB	$05,$00,$00,$00	'BHI', NO C OR Z
	FCB	$05,$01,$04,$05	'BLS', EITHER C OR Z
	FCB	$01,$00,$00,$00	'BCC', NO C
	FCB	$01,$01,$01,$01	'BCS', C SET
	FCB	$04,$00,$00,$00	'BNE', NO Z
	FCB	$04,$04,$04,$04	'BEQ', Z SET
	FCB	$02,$00,$00,$00	'BVC', V CLEAR
	FCB	$02,$02,$02,$02	'BVS', V SET
	FCB	$08,$00,$00,$00	'BPL', N CLEAR
	FCB	$08,$08,$08,$08	'BMI', N SET
	FCB	$0A,$00,$0A,$0A	'BGE', N=V
	FCB	$0A,$08,$02,$02	'BLT', N -= V
	FCB	$0E,$0A,$00,$00	'BGT', N=V, Z=0
	FCB	$0E,$08,$02,$04	'BLE', V-=N OR Z=1
	FCB	$0C,$06,$0E
* TRANSFER AND EXCHANGE REGISTER TABLE
TFREGT	FDB	SAVA	
INDTAB	FDB	SAVX	
	FDB	SAVY	
	FDB	SAVU	
	FDB	SAVS	
	FDB	SAVPC	
* PULL TABLE FOR PULS
PULSTAB	FDB	SAVCC	
	FDB	SAVA	
	FDB	SAVB	
	FDB	SAVDP	
	FDB	SAVX	
	FDB	SAVY	
	FDB	SAVU
	FDB	SAVPC	
* PULL TABLE FOR PULU
PULUTAB	FDB	SAVCC
	FDB	SAVA
	FDB	SAVB
	FDB	SAVDP
	FDB	SAVX
	FDB	SAVY
	FDB	SAVS
	FDB	SAVPC
*
GETCHR	PSHS	B,X
	LDB	>DEVICE
	BSR	DOSSR
	FCB	37
	PULS	B,X,PC
*
RDCON	PSHS	B,X
	LDB	>DEVICE
	BSR	DOSSR
	FCB	38		READ CHAR SSR 37
	PULS	B,X,PC
*
WRCON	PSHS	B,X
	LDB	>DEVICE
	BSR	DOSSR
	FCB	36		WRITE CHAR SSR 36
	PULS	B,X,PC
* FAKE SYSTEM CALL
DOSSR	PSHS	CC,A,B,DP,X,Y,U
	JMP	[SWIADR]
