DISASM.B2S

1010	REM &
	REM	!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! &
	REM	!!				       !! &
	REM	!!	   SC/MP DIS ASSEMBLER	       !! &
	REM	!!				       !!
1020	REM	!!    A.G. NICHOLSON, NEWCASTLE UNI.   !! &
	REM	!!				       !! &
	REM	!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! &

1030	REM		! LAST EDITED 13-MAY-77 ! &

1040	DIM O$(46%), O%(46%), X(3%), L(100%), C$(32%)
1050	! INITIALISE
1060	D%,F%,N0%,T%=0% &
	\ P%=1%
1070	L(0%)=-1%
1080	U$=" ####  \  \ \\ \\    \     \ \   \  \       \ "
1090	H$="0123456789ABCDEF" &
	\ READ X(I%) FOR I%=0% TO 3%
1100	DATA 1,16,256,4096
1110	READ O$(I%), O%(I%) FOR I%=1% TO 46%
1120	! MEMORY REFERENCE INSTRUCTIONS  1-8
1130	DATA LD,192,ST,200,AND,208,OR,216,XOR,224,DAD,232,ADD,240,CAD,248
1140	! TRANSFER INSTRUCTIONS  9-12
1150	DATA JMP,144,JP,148,JZ,152,JNZ,156
1160	! MEMORY INCREMENT, DECREMENT INSTRUCTIONS  13-14
1170	DATA ILD,168,DLD,184
1180	! IMMEDIATE INSTRUCTIONS  15-21
1190	DATA LDI,196,ANI,212,ORI,220,XRI,228,DAI,236,ADI,244,CAI,252
1200	! DELAY INSTRUCTION  22
1210	DATA DLY,143
1220	! POINTER MOVE INSTRUCTIONS  23-25
1230	DATA XPAL,48,XPAH,52,XPPC,60
1240	! EXTENSION REGISTER INSTRUCTIONS  26-33
1250	DATA LDE,64,XAE,1,ANE,80,ORE,88,XRE,96,DAE,104,ADE,112,CAE,120
1260	! SERIAL I/O, SHIFT & ROTATE INSTRUCTIONS  34-38
1270	DATA SIO,25,SR,28,SRL,29,RR,30,RRL,31
1280	! MISCELLANEOUS INSTRUCTIONS  39-46
1290	DATA HALT,0,CCL,2,SCL,3,IEN,5,DINT,4,CSA,6,CAS,7,NOP,8
1300	MAT READ C$
1310	! ASCII CHARACTERS 0 TO 32
1320	DATA NUL,SOH,STX,EXT,EOT,ENQ,ACK,BEL,BS,HT,LF,VT,FF,CR,SO,SI
1330	DATA DEL,DC1,DC2,DC3,DC4,NAK,SYN,ETB,CAN,EM,SUB,ESC,FS,GS,RS,US
1340	OPEN "KB:" AS FILE 1%
1350	Z%=1%	! OUTPUT CHANNEL NUMBER
1360	PRINT #1% &
	\ PRINT #1%,"SC/MP DIS-ASSEMBLER" &
	\ PRINT #1%
1370	PRINT #1%,"#"; &
	\ INPUT LINE #1%,F$ &
	\ F$=CVT$$(F$,4%)
1380	I%=INSTR(1%,F$,"<") OR INSTR(1%,F$,"=")
1390	IF I% THEN X$=LEFT(F$,I%-1%) &
	\ OPEN X$ FOR OUTPUT AS FILE 3% &
	\ PRINT #1%," OUTPUT TO ";X$ &
	\ Z%=3% &
	\ F$=RIGHT(F$,I%+1%) &
	\ PRINT #1%
1400	OPEN F$ FOR INPUT AS FILE 2% &
	\ PRINT #1%
1410	PRINT #1%," STARTING ADDRESS (HEX) ?"; &
	\ INPUT #1%,A$ &
	\ N1=FND(A$) &
	\ PRINT #1%
1420	! PASS 1
1430	PRINT #1%," PASS 1"
1440	GOSUB 2240%
1450	! GET SINGLE BYTE PORTIONS AND DECODE
1460	FOR J%=2% TO L% STEP 2%
1470	B$=MID(L$,J%-1%,2%) &
	\ GOTO 1530% IF D% &
	\ GOTO 1630% IF B$="XX"
1480	B%=FND(B$) &
	\ N0%=N0%+1%
1490	GOTO 1610% IF B%<128%
1500	! TWO BYTE INSTRUCTIONS
1510	IF J%=L% THEN D%=-1% &
	\ GOTO 1610%
1520	J%=J%+2% &
	\ B$=MID(L$,J%-1%,2%)
1530	IF B$="XX" THEN PRINT #1%, &
			"MISSING ARGUMENT AT LINE ";FNH$(N1+N0%);" (HEX)" &
	\ GOTO 1630%
1540	D%=0%	! RESET CONTINUATION BYTE
1550	N0%=N0%+1%
1560	! TEST FOR A TRANSFER INSTRUCTION
1570	IF B%<144% OR B%>159% THEN B%=FND(B$) &
	\ GOTO 1610%
1580	B%=FND(B$)
1590	! ENTER LINE NUMBER REFERENCED IN TABLE T()
1600	B%=B%-256% IF B%>127% &
	\ GOTO 1610% IF L(I%)=N1+N0%+B%+1% FOR I%=0% TO T% &
	\ T%=T%+1% &
	\ L(T%)=N1+N0%+B%+1%
1610	NEXT J%	! PROCESS NEXT CHARACTER
1620	GOTO 1440%
1630	! END PASS 1
1640	CLOSE 2%
1650	D%,F%=0%
1660	! PASS 2
1670	OPEN F$ FOR INPUT AS FILE 2% &
	\ PRINT #1%," PASS 2" &
	\ PRINT #1%
1680	PRINT #Z%,"         ADDR B1 B2     LABEL  OPCODE ARGUMENT  "; &
			"[DECIMAL]    <ASCII>" &
	\ PRINT #Z%
1690	PRINT #Z%
1700	P%=2% &
	\ N0%=0%
1710	GOSUB 2240%
1720	FOR J%=2% TO L% STEP 2%
1730	B$=MID(L$,J%-1%,2%) &
	\ GOTO 1950% IF D% &
	\ B1$=B$ &
	\ GOTO 2210% IF B$="XX"
1740	B%=FND(B$) &
	\ N0%=N0%+1%
1750	S$,O$,A$=""
1760	! CHECK TO SEE WHETHER STATEMENT IS LABELED
1770	S$="L"+CVT$$(NUM$(I%),2%)+":" IF L(I%)=N1+N0% FOR I%=0% TO T%
1780	O%=B% &
	\ GOTO 2060% IF B%<128%
1790	! TWO BYTE INSTRUCTIONS
1800	N1%=2%	! NUMBER OF BYTES
1810	! POINTER REFERENCE CHECK FOR TRANSFER, MEMORY INC/DEC
1820	FOR I%=1% TO 3% &
	\ FOR K%=9% TO 14%
1830	IF O%(K%)+I%=O% THEN A$=A$+"("+CVT$$(NUM$(I%),2%)+")" &
	\ O%=O%-I% &
	\ GOTO 1910%
1840	NEXT K% &
	\ NEXT I%
1850	! AUTO INDEX AND POINTER CHECK FOR MEMORY REFERENCE
1860	FOR K%=1% TO 8% &
	\ FOR I%=1% TO 3%
1870	IF O%(K%)+4%+I%=O% THEN A$="@("+CVT$$(NUM$(I%),2%)+")" &
	\ O%=O%-4%-I% &
	\ GOTO 1910%
1880	IF O%(K%)+I%=O% THEN A$="("+CVT$$(NUM$(I%),2%)+")" &
	\ O%=O%-I% &
	\ GOTO 1910%
1890	NEXT I% &
	\ NEXT K%
1900	! FIND OPCODE FOR DOUBLE BYTE INSTRUCTION
1910	O$=O$(I%) IF O%(I%)=O% FOR I%=1% TO 22%
1920	! GET SECOND BYTE
1930	IF J%=L% THEN D%=-1% &
	\ GOTO 2180%	! SECOND BYTE ON NEXT PHYSICAL LINE IN FILE F$
1940	J%=J%+2% &
	\ B$=MID(L$,J%-1%,2%)
1950	GOTO 2210% IF B$="XX"
1960	D%=0%
1970	B2$=B$
1980	N0%=N0%+1%
1990	! CHECK FOR TRANSFER INSTRUCTION
2000	GOTO 2030% IF B%<144% OR B%>159%
2010	! ADD LABEL REFERENCED TO ARGUMENT
2020	B%=FND(B$) &
	\ B%=B%-256% IF B%>127% &
	\ A$=A$+"L"+CVT$$(NUM$(I%),2%) IF L(I%)=N1+N0%+B%+1% FOR I%=0% TO T% &
	\ GOTO 2050%
2030	A$=A$+"X'"+B2$
2040	! OUTPUT TO CHANNEL 1
2050	GOSUB 2300% &
	\ GOTO 2180%
2060	! SINGLE BYTE INSTRUCTIONS
2070	N1%=1%	! NUMBER OF BYTES
2080	! CHECK POINTER MOVE
2090	FOR K%=23% TO 25% &
	\ FOR I%=0% TO 3%
2100	IF O%(K%)+I%=O% THEN A$=CVT$$(NUM$(I%),2%) &
	\ O%=O%-I% &
	\ GOTO 2130%
2110	NEXT I% &
	\ NEXT K%
2120	! SET OPCODE FOR SINGLE BYTE INSTRUCTION
2130	O$=O$(I%) IF O%(I%)=O% FOR I%=23% TO 46%
2140	IF O$="" THEN O$=".BYTE" \ A$="X'"+B1$
2150	B2$=""
2160	! OUTPUT TO CHANNEL 1
2170	GOSUB 2300%
2180	NEXT J%
2190	! GET NEXT LINE FROM FILE F$
2200	GOTO 1710%
2210	! EXIT
2220	CLOSE 2% &
	\ PRINT #Z% FOR I%=1% TO 3% &
	\ CLOSE 1%,3%
2230	GOTO 32767%
2240	! SUBROUTINE TO GET A LINE FROM FILE F$
2250	INPUT LINE #2%,L$ &
	\ L$=CVT$$(L$,6%) &
	\ L%=LEN(L$) &
	\ GOTO 2250% IF L%=0%
2260	! F% IS THE NUMBER OF THE LINE READ FROM FILE F$
2270	F%=F%+1%
2280	IF (L%/2%)*2%<>L% THEN PRINT #1%, &
			"INCOMPLETE BYTE READ FROM ";F$;", LINE";F% &
	\ L$=L$+" "
2290	RETURN
2300	! OUTPUT ROUTINE TO CHANNEL Z%
2310	PRINT #Z% USING U$,N0%-N1%,FNH$(N1+N0%-N1%),B1$,B2$,S$,O$,A$;
2320	!  LINE NUMBER, ADDR B1 B2  LABEL:  OPCODE  ARGUMENT
2330	IF B2$="" THEN B$=B1$ ELSE B$=B2$ &
	\ B%=FND(B$)
2340	IF B%<32% THEN C$=C$(B%+1%) ELSE IF B%<96% THEN C$=CHR$(B%)
2350	B%=B%-256% IF B%>127%
2360	PRINT #Z% USING "[ ####  ]",B%;
2370	IF C$<>"" THEN PRINT #Z% USING "    < \ \ >",C$ ELSE PRINT #Z%
2380	C$=""
2390	RETURN
2400	DEF* FNH$(X)	! HEXADECIMAL CONVERSION
2410	X0=X &
	\ X0=X0+65536 IF X0<0% &
	\ X0=INT(X0+0.1) &
	\ GOTO 2440% IF X0>65536 &
	\ X$=""
2420	FOR X%=3% TO 1% STEP -1% &
	\ X1=X(X%) &
	\ X2=INT(X0/X1) &
	\ X0=X0-X1*X2 &
	\ X2=X2+1% &
	\ X$=X$+MID(H$,X2,1%)
2430	NEXT X% &
	\ FNH$=X$+MID(H$,X0+1%,1%) &
	\ GOTO 2450%
2440	PRINT #1%,"OVERFLOW IN HEX CONVERSION" &
	\ E%=E%+1% &
	\ FNH$="    "
2450	FNEND
2460	DEF* FND(X$)	! HEX TO DECIMAL CONVERSION
2470	X=LEN(X$) &
	\ X0=0% &
	\ GOTO 2500% IF X>4%
2480	FOR X%=0% TO X-1% &
	\ X1$=MID(X$,X-X%,1%) &
	\ GOTO 2490% IF X1$=MID(H$,X1,1%) FOR X1=1% TO 16% &
	\ PRINT #1%,"ILLEGAL CHARACTER IN HEX NUMBER :";X$ &
	\ GOTO 2510%
2490	X0=X0+(X1-1%)*X(X%) &
	\ NEXT X% &
	\ FND=X0 &
	\ GOTO 2520%
2500	PRINT #1%,"OVERFLOW IN DECIMAL CONVERSION :"
2510	E%=E%+1% &
	\ FND=0%
2520	FNEND
32767	END