C/C++ Users Group Library 1996 July

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Assembly Source File | 1994-02-14 | 19.1 KB | 646 lines

TITLE 8080/8085 SYSTEM MONITOR **************************************************************** * 8080/8085 SYSTEM MONITOR * *--------------------------------------------------------------* * COMMANDS: * * B .................... ENTER RESIDENT BASIC INTERPRETER. * * D .................... DOWNLOAD FROM TERMINAL PORT. * * G <ADR> .............. GO (EXECUTE) AT ADDRESS. * * L .................... LOAD MEMORY FROM TAPE. * * M <ADR>,<ADR> ........ DISPLAY MEMORY IN HEXIDECIMAL. * * R .................... REENTER RESIDENT BASIC. * * S <ADR> [NN]-<BYT> ... SUBSTUTE INTO MEMORY. * * T 'H' OR 'F' ......... TERMINAL EMULATION MODE. * * U <WRD> .............. REINITIALIZE 8251 UART. * * W <ADDR>,<ADDR> ...... WRITE MEMORY TO TAPE. * **************************************************************** PAGE * * CONSTANTS AND EQUATES... * DEFIO EQU 3 DEFAULT I/O CONFIGURATION KEYBRD EQU 0 KEYBOARD INPUT PORT UCTL EQU 2 UART CONTROL/STATUS PORT UDAT EQU 1 UART DATA PORT VIDEO EQU $1000 VIDEO DISPLAY RAM ADDRESS BUFF EQU $1400 INPUT BUFFER IOCON EQU BUFF+$FF I/O CONFIGURATION USROUT EQU IOCON-2 USER OUTPUT ROUTINE VECTOR CURSOR EQU USROUT-2 CURRENT CURSOR POSITION LSTCHR EQU CURSOR-1 CHARACTER UNDER CURSOR STACK EQU LSTCHR SYSTEM STACK BASIC EQU $400 ADDRESS OF RESIDENT BASIC INTERPRETER RENTRY EQU BASIC+$A3 ADDRESS TO REENTER BASIC PAGE * * START OF MONITOR, FIRST INITIALIZE THE HARDWARE * START LXI SP,STACK INITALIZE STACK LXI H,0 SET USRIO TO ZERO... SHLD USROUT TO INDICATE IT HASN'T BEEN SET MVI A,DEFIO DEFAULT I/O CONFIGURATION STA IOCON SET I/O CONFIGURATION LXI H,$7A37 USART 7 BITS, NO PARITY, HIGH-SPEED CALL SETURT INITIALIZE 8251 MVI A,$0C CLEAR SCREEN CHARACTER CALL OUT DISPLAY JMP PRNT PROMPT FOR COMMAND * GETS DOUBLE VALUE FOR HL, DE DGET CALL AGET GET FIRST ADDRESS XCHG SWAP MVI A,',' GET SEPERATOR CHARACTER CALL OUT DISPLAY * GETS TWO BYTE VALUE FOR H-L AGET CALL GETHL GET HEX VALUE RC RETURN IF OK * INDICATE ERROR WITH '?' ON CONSOLE ERROR MVI A,'?' ERROR MESSAGE CALL OUT DISPLAY IT * RECOVER FROM ERROR, RESET STACK, SHUT TAPE OFF ABORT LXI SP,STACK FIX UP STACK CALL TOFF SHUT OFF TAPE CALL NL NEW LINE ON TERMINAL * WAIT FOR COMMAND PRNT MVI A,'*' PROMPT MESSAGE CALL OUT DISPLAY CALL IN GET CHARACTER FROM TERMINAL CALL OUT ECHO MOV B,A SAVE FOR COMPARISON CALL SPACE DISPLAY SEPARATER LXI H,CTAB POINT TO COMMAND TABLE CLOOK MOV A,M GET CMD FROM TABLE INX H POINT TO NEXT ANA A TEST FOR END IF TABLE JZ ERROR IF SO, INDICATE SO MOV E,M GET LOW ADDRESS INX H POINT TO HIGH MOV D,M GET HIGH ADDRESS INX H POINT TO NEXT CMP B TEST FOR ENTERED COMMAND JNZ CLOOK KEEP LOOKING TILL WE FIND LXI H,ABORT ADDRESS TO RETURN TO PUSH H SAVE RETURN ADDRESS XCHG SWAP TO H-L PCHL EXECUTE USER CODE CTAB DB 'B' BASIC COMMAND? DW BASIC ADDRESS OF BASIC INTERPRETER DB 'R' TEST FOR 'REENTER' DW RENTRY REENTER BASIC DB 'D' TEST FOR DOWNLOAD DW DNLD PERFORM DOWNLOAD DB 'L' TEST FOR 'LOAD' DW LOAD LOAD FROM TAPE DB 'U' TEST FOR 'UART' DW UART SET UP UART DB 'G' TEST FOR 'GO' DW GO GO EXECUTE DB 'S' TEST FOR 'SUB' DW SUBST SUBST. MEMORY DB 'W' TEST FOR 'WRITE' DW DUMP DUMP SOME OUT DB 'M' TEST FOR 'M' DW MEMRY MEMORY CODE DB 'T' TERMINAL MODE??? DW TMODE IF SO, ENTER TERMINAL DB 0 INDICATE END OF TABLE * * DISPLAY MEMORY COMMAND * MEMRY CALL DGET GET ADDRESSES XCHG SWAP BACK MLOOP CALL NL START A NEW LINE CALL HLOUT DISPLAY ADDRESS ML1 CALL SPACE DISPLAY SPACE MOV A,M GET CONTENTS CALL HOUT DISPLAY HEX CALL CHLDE TEST FOR END RNC IF SO, STOP INX H NEXT BYTE MOV A,L GET LOW ADDRESS ANI $0F TEST FOR END OF LINE JNZ ML1 IF NOT, KEEP GOING CALL CTRLC TEST FOR USER ABORT JNZ MLOOP IF NOT, KEEP DISPLAYING RET * * GO COMMAND * GO CALL AGET GET ADDRESS TO 'GO' AT PCHL SET PROGRAM COUNTER * * SUBSTUTUTE COMMAND * SUBST CALL AGET GET ADDRESS SUB0 CALL NL START ON A NEW LINE CALL HLOUT DISPLAY ADDRESS MVI D,8 EIGHT BYTES/LINE SUB1 CALL SPACE SKIP A SPACE MOV A,M GET CONTENTS CALL HOUT DISPLAY MVI A,'-' PROMPT WITH '-' CALL OUT DISPLAY CALL GETBYT GET BYTE JC SUB3 IF OK, SUBSTUTE CPI $0D TEST FOR ABORT RZ IF SO, BACK FOR COMMAND CALL SPACE OTHERWISE, PRINT. CALL SPACE TWO SPACES (SAME SPACE AS HEX DIGITS) MOV A,M GET OLD BYTE BACK SUB3 MOV M,A REPLACE MEMORY CONTENTS SNXT INX H NEXT LOCATION IN MEMORY DCR D REDUCE COUNT OF BYTES/LINE JNZ SUB1 IF OK, STAY ON SAME LINE JMP SUB0 OTHERWISE GO TO NEW LINE * * DUMP COMMAND * DUMP CALL DGET GET ADDRESSES * DE=START ADDRESS, H-L=END ADDRESS DUMP1 INX H ADVANCE BY ONE BYTE MOV A,H TEST FOR SPECIAL CASE ANA A IF ZERO PAGE JZ LBOT IF SO, SPECIAL CASE PUSH H SAVE ENDING VALUE LXI B,$FF01 GET VALUE TO SUBTRACT DAD B SUBTRACT FROM ENDING ADDRESS XCHG SWAP BACK CALL TON START TAPE DRIVE DRECL CALL CHLDE SEE IF WE HAVE FINISHED YET JNC LREC IF SO, LAST RECORD MVI A,$FF OTHERWISE, RECORD LENGTH IS 255 CALL DUMPR DUMP OUT RECORD JMP DRECL KEEP GOING TILL LAST RECORD LREC POP D GET ADDRES BACK XCHG SWAP LBOT PUSH D GET ADDRESS BACK MOV A,D TAKE. CMA TWO'S. MOV D,A COMPLEMENT. MOV A,E SO WE CAN. CMA SUBTRACT. MOV E,A FROM THE INX D ORIGIONAL ADDRESS DAD D SUBTRACT MOV A,L GET LENGTH POP H GET ADDRESS BACK CALL DUMPR DUMP LAST RECORD SUB A END OF FILE INDICATOR * * DUMPS A RECORD IN INTEL HEX FORMAT * DUMPR MOV B,A SAVE LENGTH IN B MVI A,4 SET FOR UART OUTPUT STA IOCON SET I/O CONF CALL NL DISPLAY LF CR TO TAPE MVI A,':' START OF RECORD CALL OUT WRITE TO TABE MOV A,B GET LENGTH MOV C,A START CHECKSUM CALL HOUT WRITE LENGTH TO TAPE MOV A,B GET LENGTH BACK ANA A TEST FOR END OF FILE JZ ENDMP IF SO, STOP CALL HLOUT WRITE ADDRESS TO TAPE MOV A,C GET CHECKSUM ADD H ADD HIGH ADDRESS ADD L ADD LOW ADDRESS MOV C,A RESAVE CHECKSUM SUB A DATA TYPE ZERO CALL HOUT WRITE TO TAPE MHEX MOV A,M GET BYTE OF DATA TO DUMP CALL HOUT WRITE TO TAPE MOV A,M GET DATA BACK ADD C ADD TO CHECKSUM MOV C,A RESAVE CHECKSUM INX H NEXT MEMORY LOCATION DCR B REDUCE LENGTH JNZ MHEX IF NOT END, KEEP DUMPING CMA INVERT TO MAKE. INR A TWO'S COMPLEMENT CHECKSUM CALL HOUT WRITE CHECKSUM TO TAPE ENDMP MVI A,DEFIO GET DEFAULT I/O CONF STA IOCON RESET I/O CONFIGURATION RET * * COMPARE'S H-L WITH D-E * CHLDE MOV A,H GET HIGH IF HL CMP D TEST WITH HIGH OF DE RNZ IF NOT SAME, PROBLEM SOLVED MOV A,L GET LOW HL CMP E SET FLAGS FOR COMPARE WITH LOW DE RET * DISPLAYS A SPACE ON THE TERMINAL SPACE MVI A,' ' GET A SPACE JMP OUT DISPLAY * * DISPLAYS 16 BIT VALUE OF H-L ON THE TERMINAL * HLOUT MOV A,H GET H CALL HOUT DISPLAY H IN HEX MOV A,L GET L * DISPLYS 8 BIT VALUE OF ACC IN HEX HOUT PUSH PSW SAVE LOW DIGIT RRC MAKE HIGH. RRC DIGIT. RRC INTO. RRC LOW DIGIT. CALL HXOUT PRINT HIGH DIGIT POP PSW GET LOW DIGIT BACK HXOUT ANI $0F GET RID OF EXCESS BAGGAGE ADI $30 CONVERT TO ASCII NUMBER CPI $3A TEST FOR ALPHA CHARACTER JC OUT IF NOT, WE ARE OK ADI 7 CONVERT TO CHARACTER * * OUTPUT ROUTINE, DISPLAYS CONTENTS OF ACC ON ALL ENABLED * OUTPUT DEVICES * OUT PUSH B SAVE B-C PAIR PUSH D SAVE D-E PAIR PUSH H SAVE H-L PAIR MOV B,A SAVE CHARACTER IN B LDA IOCON GET I/O CONFIGURATION MOV C,A SAVE IN C ANI $40 TEST FOR OUTPUT DISABLED JNZ OEXIT IF SO, ABORT MOV A,C GET CONFIGURATION BACK ANI 2 TEST FOR VIDEO DISPLAY ENABLED JZ OURT NO, TRY UART * OUTPUT TO VIDEO DISPLAY OVID LHLD CURSOR GET CURSOR POSITION LDA LSTCHR GET CHARACTER UNDER CURSOR MOV M,A REPLACE CURSOR MOV A,B GET CHARACTER TO PRINT CPI 13 TEST FOR CR JZ CR ADVANCE TO NEXT LINE CPI 10 TEST FOR LINE-FEED JZ LF ADVANCE TO NEXT LINE CPI 8 TEST FOR BACKSPACE JZ BS BACK UP CPI 14 TEST FOR SHIFT-IN JZ SI ENABLE EIGHTH BIT CPI 15 TEST FOR SHIFT-OUT JZ SO DISABLE EIGHTH BIT CPI $0C TEST FOR CLEAR SCREEN JZ CLRSCR CLEAR THE SCREEN CPI $0B TEST FOR HOME CHARACTER JZ HOME HOME THE CURSOR MOV A,C GET I/O CONFIGURATION ANI $80 ELIMINATE ALL BUT SPECIAL EFFECTS BIT ORA B OR IN CHARACTER TO BE PRINTED MOV M,A DISPLAY ON SCREEN INX H ADVANCE TO NEXT POSITION ON SCREEN MOV A,H GET HIGH ADDRESS CPI =VIDEO+1024 TEST FOR OFF SCREEN JNZ VEND IF NOT, WE ARE OK CALL ROLL SCROLL THE SCREEN LXI H,VIDEO+960 POSITION TO FIRST POSITION OF LAST LINE VEND MOV A,M GET CHARACTER UNDER CURSOR STA LSTCHR SAVE IN MEMORY MVI M,$7F PLACE CURSOR ON SCREEN SHLD CURSOR SAVE CURSOR POSITION JMP OURT TEST FOR UART OUTPUT * DISPLAY CARRIAGE RETURN ON TERMINAL CR MOV A,L GET LOW SCREEN ADDRESS ANI $C0 BACK UP TO FIRST POS. IN LINE MOV L,A REPLACE IN ADDRESS JMP VEND TERMINATE * LINE-FEED LF XCHG SWAP POSITION TO D-E LXI H,64 ADD 64 TO IT DAD D GO DOWN ONE LINE MOV A,H GET HIGH ADDRESS CPI =VIDEO+1024 TEST FOR BEYOND END JNZ VEND IF NOT, WE ARE OK XCHG GET ADDRESS BACK CALL ROLL SCROLL SCREEN JMP VEND TERMINALE * BACK SPACE BS DCX H BACK UP POSITION MOV A,H GET HIGH ADDRESS CPI =VIDEO-1 TEST FOR BEFORE SCREEN JNZ VEND IF NOT, WE ARE OK INX H ADVANCE BACK TO VIDEO SCREEN JMP VEND TERMINATE * SHIFT OUT, DISABLE EXTRA BIT SO MOV A,C GET I/O CONFIGURATION ANI $7F REMOVE EXTRA BIT SAVIO STA IOCON RESAVE JMP VEND TERMINATE * SHIFT IN, ENABLE SPECIAL CHARACTERS SI MOV A,C GET I/O CONFIG ORI $80 ENABLE EXTRA BIT JMP SAVIO SAVE AND TERMINATE * ROLLS SCREEN ROLL PUSH H SAVE H-L LXI H,VIDEO GET VIDEO ADDRESS LXI D,VIDEO+64 SECOND LINE ON SCREEN RLP1 LDAX D GET CHARACTER FROM LINE MOV M,A STORE ONE LINE BACK INX H ADVANCE POSITION INX D ADVANCE POSITION MOV A,D GET ADDRESS CPI =VIDEO+1024 TEST FOR END OF SCREEN JNZ RLP1 IF NOT, KEEP GOING * CLEAR LAST LINE RLP2 MVI M,' ' CLEAR ONE CHARACTER INX H POINT TO CHARACTER CMP H TEST FOR END OF SCREEN JNZ RLP2 IF NOT, KEEP GOING POP H RESTORE H-L RET * CLEAR SCREEN CLRSCR MVI A,=VIDEO+1024 ADDRESS OF END OF SCREEN LXI H,VIDEO STARTING ADDRESS CLR1 MVI M,' ' CLEAR ONE CHARACTER INX H POINT TO NEXT CHARACTER CMP H TEST FOR OVER END JNZ CLR1 IF NOT, KEEP GOING * HOME CURSOR HOME LXI H,VIDEO SET CURSOR ADDRESS TO TOP LEFT HAND JMP VEND TERMINATE * TEST FOR UART OUTPUT OURT MOV A,C GET I/O CONFIGURATION ANI 4 TEST FOR UART ENABLED JZ OUSR IF NOT, TRY USER SUPPLIED ROUTINE ULP1 IN UCTL GET UART STATUS RRC TEST FOR XMIT READY JNC ULP1 IF NOT, KEEP TRYING MOV A,B GET CHARACTER OUT UDAT OUTPUT TO UART * USER SUPLIED OUTPUT DEVICE OUSR MOV A,C GET I/O CONFIGURATION ANI $08 TEST FOR USER DEVICE ENABLED JZ OEXIT IF NOT, EXIT LXI H,OEXIT ADDRESS TO RETURN TO PUSH H SAVE ON STACK LHLD USROUT ADDRESS TO JUMP TO PCHL CALL HIS ROUTINE OEXIT POP H RESTORE H-L POP D RESTORE D-E MOV A,B CHARACTER IS IN A POP B RESTORE B-C RET * * INPUT ROUTINE, INPUTS FROM SELECTED DEVICE * IN PUSH B SAVE B-C PAIR INS1 LDA IOCON GET INPUT/OUTPUT CONFIGURATION MOV B,A SAVE COPY IN B FOR FAST REFERENCE RRC TEST FOR INPUT FROM KEYBOARD JC KBD IF SO, GET CHARACTER FROM KBD * READ FROM UART UIN IN UCTL GET UART STATUS ANI 2 TEST FOR RECEIVED CHARACTER JZ UIN IF NOT, WAIT FOR IT IN UDAT GET DATA FROM UART JMP INEND PROCESS * READ FROM KEYBOARD KBD IN KEYBRD GET KEYBOARD DATA RLC TEST FOR KEY ALREADY PRESSED JC KBD IF SO, WAIT FOR RELEASE KBD1 IN KEYBRD GET KEYBOARD DATA XRI $80 TEST FOR AND REMOVE STROBE JM KBD1 IF NOT, WAIT FOR A KEY * PROCESS CHARACTER JUST READ, ACCORDING TO DEFAULTS INEND MOV C,A SAVE CHARACTER CPI 3 TEST FOR CONTROL-C MOV A,B GET IO CONFIGURATION JZ CTLC IF CTRL-C, SPECIAL CASE ANI $10 TEST FOR UPPER CASE CONVERSIN MOV A,C GET CHARACTER BACK POP B RESTORE B-C PAIR RNZ IF UPPER CASE DISABLED, THEN DON'T CHANGE CPI $61 TEST FOR < LOWER CASE 'A' RC IF SO, THEN DON'T CHANGE CPI $7B TEST FOR > LOWER CASE 'Z' RNC IF SO, DON'T CHANGE ANI $5F CONVERT TO UPPER CASE RET * CONTROL-C, DON'T PASS ON IF CTRL-C IS DISABLED CTLC ANI $20 TEST FOR CONTROL-C DISABLED JNZ INS1 IF SO, GET NEXT CHARACTER MOV A,C GET CHARACTER BACK POP B RESTORE B-C RET * * TEST FOR CTRL-C FROM KEYBOARD. ALSO, IF LINE-FEED IS PRESSED, * THEN WAIT TILL IT IS RELEASED * CTRLC IN KEYBRD GET KEYBOARD DATA XRI $80 TEST AND REMOVE STROBE RM IF NO KEY, QUIT CPI $0A TEST FOR LINE-FEED JZ CTRLC IF SO, WAIT TILL RELEASED CPI 3 TEST FOR CONTROL-C RNZ IF NOT, DON'T PROCESS LDA IOCON GET I/O CONFIGURATION ANI $20 TEST FOR CONTROL-C INHIBIT. (Z=0 IF NOT) RET * SET UART COMMAND UART CALL AGET GET 16 BIT VALUE * * INITIALIZES 8251 USART TO VALUE PASSED IN H-L * SETURT MVI A,3 VALUE TO RESET UART OUT UCTL MAKE SURE. OUT UCTL UART IS RESET MVI A,$77 VALUE TO ENTER COMMAND MODE OUT UCTL ENTER COMMAND MODE MOV A,H GET HIGH BYTE OF NEW COMMAND WORD OUT UCTL WRITE TO CONTROL PORT MOV A,L GET LOW BYTE OF NEW COMMAND WORD OUT UCTL WRITE TO CONTROL PORT RET * GET'S A 16 BIT VALUE FOR H-L, CY=1 IF EVERYTHING OK GETHL CALL GETBYT GET FIRST BYTE RNC IF BAD, DON'T WAIT FOR SECOND MOV H,A SAVE IN HIGH BYTE OF RESULT CALL GETBYT GET SECOND BYTE MOV L,A SAVE IN LOW BYTE OF RESULT RET * GETS A BYTE FOR ACC FROM TERMINAL, CY=0 IF FAILS GETBYT PUSH B SAVE B-C PAIR CALL GETNIB GEET FIRST NIBBLE JNC RETGB IF BAD, DON'T WAIT FOR MORE RLC SHIFT INTO. RLC UPPER NIBBLE. RLC OF RESULT. RLC SO WE CAN INSERT LOWER NIBBLE MOV B,A KEEP HIGH DIGIT IN B CALL GETNIB GET SECOND DIGIT JNC RETGB IF BAD, INDICATE SO ORA B INSERT HIGH DIGIT STC INDICATE SUCESS RETGB POP B RESTORE B-C PAIR RET * GETS A NIBBLE FROM THE TERMINAL (IN ASCII HEX) GETNIB CALL IN GET A CHARACTER CPI ' ' TEST FOR BLANK (ABORT1) RZ IF SO, RETURN INDICATING BAD (CY=0) CPI $0D TEST FOR <CR> (ABORT2) RZ IF SO, RETURN INDICATING BAD CPI '0' TEST FOR INVALID (BELOW '0') JC GETNIB IF SO, WAIT FOR MORE CPI 'G' TEST FOR INVALID (GREATER THAN 'F') JNC GETNIB IF SO, IGNORE CALL OUT DISPLAY CHARACTER CPI $3A TEST FOR INVALID JC NUMH IF OK, WE ARE IN CPI 'A' TEST FOR INVALID JC GETNIB IF BAD, IGNORE SUI 7 CONVERT TO DIGIT NUMH SUI $30 CONVERT TO BINARY STC INDICATE SUCESS RET * LOADS A RECORD IN INTEL HEX FORMAT GETR MVI A,$42 INHIBIT OUTPUT, ENABLE UART STA IOCON SET I/O CONF MVI A,' ' CLEAR VIDEO FLAG STA VIDEO+63 SO WE CAN FLASH A STAR GET1 CALL IN GET CHARACTER FROM TAPE CPI ':' TEST FOR START OF RECORD JNZ GET1 IF NOT, IGNORE LDA VIDEO+63 GET VIDEO SCREEN CONTENTS XRI $0A CONVERT TO/FROM A STAR STA VIDEO+63 RESAVE VIDEO CONTENTS CALL GETBYT GET LENGTH ANA A TEST FOR END OF FILE JZ RSET IF SO, PROCESS MOV C,A START CHECKSUM MOV B,A REMEBMER LENGTH CALL GETHL GET ADDRESS MOV A,C GET CHECKSUM ADD H ADD HIGH BYTE OF ADDRESS ADD L ADD LOW BYTE OF ADDRESS MOV C,A RESAVE CHECKSUM CALL GETBYT GET TYPE BYTE ADD C ADD TO CHECKSUM MOV C,A RESAVE CHECKSUM NEOR CALL GETBYT GET DATA BYTE MOV M,A SAVE IN MEMORY INX H POINT TO NEXT LOCATION ADD C ADD TO CHECKSUM MOV C,A RESAVE CHECKSUM DCR B REDUCE COUNT OF REMAINING DATA BYTES JNZ NEOR IF MORE, KEEP LOADING CALL GETBYT GET CHECKSUM. (FROM TAPE) ADD C ADD TO COMPUTED CHECKSUM JZ EIPL IF OK, END THIS RECORD CALL RSET CLEAR FLAGS LXI H,ERRMSG ADDRESS OF '?I/O ERROR' MESSAGE CALL PMSG PRINT MESSAGE ANA A INDICATE END OF LOAD RET * INDICATE END OF RECORD, MORE DATA TO FOLLOW (CY=1) EIPL CALL RSET RESET DEFAULT I/0 STC INDICATE MORE DATA RET * RESET I/O CONFIGURATION RSET MVI A,DEFIO SET TO DEFAULT I/O STA IOCON SAVE IN I/O CONF ANA A INDICATE DONE RET ERRMSG STR '?I/O ERROR' ERROR MESSAGE DB $0D * DISPLAYS MESSAGE ON DISPLAY UP TO A CARRIAGE-RETURN. OR ZERO PMSG MOV A,M GET CHARACTER FROM MESSAGE ANA A END OF MESSAGE? RZ IF SO, RETURN CALL OUT DISPLAY IT INX H POINT TO NEXT CHAR. IN MESSAGE CPI $0D TEST FOR CARRIAGE RETURN JNZ PMSG IF NOT, KEEP DISPLAYING * DISPLAYS A LINE-FEED, CARRIAGE-RETURN PAIR ON THE VIDEO DISPLAY NL MVI A,$0A GET LINE-FEED CALL OUT DISPLAY MVI A,$0D GET CARRIAGE RETURN JMP OUT DISPLAY AND RETURN * LOAD COMMAND LOAD CALL TON TURN TAPE ON * DOWNLOAD COMMAND DNLD MVI D,$FF SET NUMBER OF RECORDS DUMPED TO 255 CALL NL ADVANCE TO A NEW LINE LODLP INR D ADVANCE NUMBER OF RECORDS DUMPED MOV A,D GET NUMBER OF RECORDS DUMPED CALL HOUT DISPLAY ON TERMINAL CALL GETR GET NEXT RECORD RNC IF END, GET NEXT COMMAND MVI A,$0D GET CARRIAGE RETURN CALL OUT BACK UP TO START OF LINE JMP LODLP GET NEXT RECORD * POSITIONS CURSOR TO POSITION PASSED IN H-L CURPOS PUSH D SAVE D-E XCHG SWAP TO D-E LHLD CURSOR GET OLD CURSOR POSITION LDA LSTCHR GET LAST CHARACTER MOV M,A REPLACE IN SCREEN MEMORY LXI H,VIDEO START OF VIDEO DISPLAY DAD D OFFSET INTO DISPLAY MOV A,M GET CHARACTER UNDER NEW CURSOR STA LSTCHR SAVE IN MEMORY MVI M,$7F PUT CURSOR ON SCREEN SHLD CURSOR RESAVE CURSOR POSITION POP D RESTORE D-E RET * START TAPE DRIVE, AND WAIT TON MVI A,$35 SET FOR TAPE ON OUT UCTL WRITE TO UART CONTROL * DELAY, WAITS A FINITE TIME INTERVAL DELAY PUSH H SAVE H-L LXI H,0 START COUNTING FROM ZERO DEL1 DCX H REDUCE COUNT MOV A,H GET HIGH VALUE ORA L TEST FOR ZERO WITH LOW VALUE JNZ DEL1 IF NOT, KEEP COUNTING POP H RESTORE H-L RET * SHUT'S OFF TAPE DRIVE TOFF IN UCTL GET UART DATA RRC WAIT FOR XMIT READY JNC TOFF TO WE DON'T CLOBBER LAST CHAR SENT MVI A,' ' GET A BLANK STA VIDEO+63 INSURE DISPLAYED '*' IS OFF MVI A,$37 SHUT OFF TAPE DRIVE OUT UCTL TURN IT OFF RET * * TERMINAL MODE.... SIMULATES A DUMB ASCII TERMNAL * TMODE CALL IN GET DATA CHARACTER MOV B,A SAVE IN B FOR LATER REF * READ/WRITE TERMINAL AND UART TWAIT CALL CRCVR TEST UART RECEIVER IN KEYBRD GET KEYBOARD DATA RLC TEST FOR KEY PRESSED JC TWAIT IF SO, WAIT TILL RELEASED KEYIN CALL CRCVR TEST FOR UART DATA RECEIVED IN KEYBRD GET KEYBOARD DATA XRI $80 TEST AND REMOVE STROBE JM KEYIN IF NO DATA, WAIT FOR SOME RZ IF NULL (CTRL-@) RETURN TO MONITOR OUT UDAT WRITE TO UART DATA PORT MOV C,A SAVE FOR REFERENCE MOV A,B GET DUPLEX INDICATOR CPI 'H' TEST FOR HALF DUPLEX MOV A,C GET CHARACTER BACK CZ PCHRS IF HALD DUP, DISPLAY CHAR JMP TWAIT WAIT FOR KEY RELEASE * TEST UART AND DISPLAY AND DATA RECEIVED CRCVR IN UCTL GET UART STATUS ANI 2 TEST FOR RX READY RZ IF NOT, FORGET IT IN UDAT GET UART DATA PCHRS CPI $0D TEST FOR CARRIAGE RETURN JZ OUT OK TO DISPLAY CPI $0A TEST FOR LINE-FEED JZ OUT OK TO DISPLAY CPI $08 TEST FOR BACK-SPACE JZ OUT OK TO DISPLAY CPI $7F TEST FOR DELETE CHARACTER RZ NOT OK TO DISPLAY CPI ' ' TEST FOR CONTROL CHARACTERS JNC OUT ONLY DISPLAY DISPLAYABLE CHARACTERS RET