CP/M

home *** CD-ROM | disk | FTP | other *** search

/ CP/M / CPM_CDROM.iso / simtel / cpmug / cpmug035.ark / NUMBER.ASM < prev next >

Wrap

Assembly Source File | 1984-04-29 | 14.5 KB | 448 lines

;16 MAR 79,MOSHELL: REMOVE STTACK-INIT.IN 'MOVE'. ;************************************************************************ ; ; NUMBER GROUP * MOVE, COMP, COMPU, ADD, SUBT * ; 1/79 * JANE KIENINGER ; ; ; NOTES: ; 1. WHEN AN 8 BIT PARAMETER IS PROCESSED AGAINST A 16 BIT PARAMETER, ; THE 8 BIT PARAMETER IS TREATED LIKE A 16 BIT PARAMETER ; WITH 0'S IN THE HIGH ORDER 8 BITS - FLAGS AND PROCESSING ; PROGRESS AS IF BOTH WERE 16 BITS (MOVE ROUTINE IS NOT ; AFFECTED). ; 2. COMPARE - USE 'COMP' TO COMPARE SIGNED INTEGERS, USE 'COMPU' ; TO COMPARE UNSIGNED. ; 3. ADD - TO DETECT A RESULT WHICH HAS EXCEEDED STORAGE ALLOWED: ; A. CHECK CARRY FLAG FOR UNSIGNED INTEGERS. ; B. CHECK OVERFLOW FLAG FOR SIGNED INTEGERS. ; 4. SUBT - ; A. FOR UNSIGNED INTEGERS CHECK CARRY FLAG TO DETECT A ; NEGATIVE RESULT. ; B. FOR SIGNED INTEGERS CHECK OVERFLOW FLAG TO DETECT A RESULT ; WHICH HAS EXCEEDED STORAGE ALLOWED. ; 5. MINUS FLAG - IS SET: ; A. IN ADD, SUB OR MOVE ROUTINES TO INDICATE THAT THE ; RESULLT (OR PARAMETER OF 'MOVE') IS NEGATIVE - TO ; BE USED WITH SIGNED INTEGERS ONLY. ; B. IN COMP, TO INDICATE THAT THE SECOND PARAMETER IS GREATER ; THAN THE FIRST WHEN DEALING WITH SIGNED INTEGERS. ; C. IN COMPU, TO INDICATE THAT THE SECOND PARAMETER IS ; GREATER THAN THE FIRST WHEN DEALING WITH ; UNSIGNED INTEGERS. ; ; 6. WARNING - IF SIGNED AND UNSIGNED PARAMETERS ARE INADVERTANTLY ; MIXED, RESULTS AND FLAGS ARE UNPREDICTABLE. ; ;;************************************************************************ INPARM EQU 5030H OUTPRM EQU 5033H FLAGS EQU 0114H ;(*REGISTER #2) MFLAG EQU 80H ; LOCATION OF MINUS FLAG (BIT 7) OFFM EQU 7FH ; TO TURN OFF MINUS FLAG ZFLAG EQU 40H ; LOCATION OF ZERO FLAG (BIT 6) OFFZ EQU 0BFH ; TO TURN OFF ZERO FLAG ZAPFLAG EQU 3FH ; TO TURN OFF BOTH ZERO AND MINUS (BIT 6 AND 7) CFG EQU 02H ; TO TURN ON CARRY FLAG (BIT 1) OFG EQU 08H ; TO TURN ON OVERFLOW FLAG (BIT 3) ZAPALL EQU 35H ; TO TURN OFF ALL FELIX FLAGS (BITS 1,3,6,7) ON EQU 0FFH ; USED TO TURN INTERNAL FLAG ON ZERO EQU 00H ; ORG 5300H RESULT DB 00H ; TEMPORARY SAVE AREA FOR COMPUTATIONAL RESULTS RTSW DB 00H ; ROUTINE SWITCH ;************************************************************************* ; ; MOVE * MOVE ROUTINE * J-2LANE KIENINGER ; * 1/79 * VERSION 1.1 ; ; DESCR: THIS ROUTINE EXAMINES THE FIRST PARAMETER AND ; SETS MINUS AND ZERO (FELIX) FLAGS AS NECESSARY. ; IT TESTS THE SIGN FLAG SET BY INPARM TO DETERMINE WHETHER 8 OR ; 16 BITS SHOULD BE EXAMINED. OUTPRM ACTUALLY MOVE THE VALUE TO A ; NEW VARIABLE. ; INPUT: REGISTERS D AND E FROM INPARM. ; OUTPUT: REGISTERS D AND E TO OUTPRM. ; SUBROUTINES: INPARM, OUTPRM ; REGISTERS DESTROYED: A AND B ; ;**************************************************************************** MOVE: LDA FLAGS ; ZERO FLAGS ANI ZAPFLAG STA FLAGS MVI B,00H ; ZERO B USED TO INDICATE 16 BIT PARAMETER SIZE CALL INPARM ; GET PARAMETER JC BIT16 ; IF CARRY FLAG SET, PARAMETER SIZE IS 16 BITS ; ; SET MINUS FLAG FOR 8-BIT IF NEGATIVE ; MOV A,E ; IF E IS NEGATIVE CPI 0H ; SET MINUS FLAG TEMPORARILY IN B JP CKZERO MVI B,MFLAG JMP CKZERO ; ; SET MINUS FLAG FOR 16 BIT IF NECESSARY ; BIT16: MOV A,D ; IF D IS NEGATIVE SET TEMPORARY MINUS FLAG IN B CPI 0H ; JP CKZERO MVI B,MFLAG CKZERO: MOV A,D ; CHECK TO SEE IF VALUE =0 ORA E LDA FLAGS ; UPDATE FLAGS JNZ MVEND ORI ZFLAG ; SET ZERO FLAG MVEND: ORA B ; SET MINUS FLAG FROM B STA FLAGS ; RESTORE FLAGS CALL OUTPRM ; CALL OUTPRM TO GET VALUE TO BE MOVED RET ;******************************************************************** ; COMP/COMPU * COMPARE SIGNED (COMP) AND COMPARE UNSIGNED (COMPU) ROUTINES * ; * JANE KIENINGER ; * 1/79 * VERSION 1.1 ; ; DESCR: THIS ROUTINE COMPARES THE SECOND PARAMETER VALUE FROM ; THE FIRST. IF THE SECOND VALUE IS GREATER THAN THE FIRST THE ; FELIX MINUS FLAG IS SET AND IF THE RESULT IS ZERO (THE VALUES ; ARE EQUAL) THE FELIX ZERO FLAG IS SET. THE MINUS FLAG IS ; SET BASED ON THE 16 BITS OF THE RESULT EXCEPT WHEN BOTH ; PARAMETER VALUES ARE 8 BITS AS INDICATED BY THE CARRY FLAG ; SET BY INPARM - IN THAT CASE THE MINUS FLAG IS SET BASED ; ON THE LOWER 8 BITS OF DE. ; COMP SETS THE FLAGS ASSUMING BOTH PARAMETERS ARE SIGNED ; INTEGERS WHILE COMPU SETS THE FLAGS ASSUMING THEY ARE UNSIGNED ; INTEGERS. THE ENTRY POINT INTO THIS ROUTINE DETERMINES WHETHER ; IT WILL DO A SIGNED OR UNSIGNED COMPARE. A ROUTINE FLAG IS SET ; (RTSW) TO 00 FOR UNSIGNED AND FF FOR SINGED. ; INPUT: REGISTERS D AND E FROM INPARM ; OUTPUT: FELIX FLAGS ZERO (BIT 6) AND MINUS (BIT 7) SET ; SUBROUTINES: INPARM ; REGISTERS DESTROYED: ALL ; ;*************************************************************************** ORG 5340H ; ; UNSIGNED COMPARE ROUTINE START POINT ; CKMPU: XRA A ; SET ROUTINNE SWITCH TO 0 STA RTSW ; JMP C0 ; ; ; SIGNED COMPARE ROUTINE START POINT ; ORG 5350H COMP: ORI ON ; SET ROUTINE SWITCH TO FF TO INDICATE STA RTSW ; SIGNED NUMBERS. ; ; BEGIN COMPARE ROUTINE ; C0: LDA FLAGS ; ZERO FLAGS ANI ZAPFLAG STA FLAGS MVI B,00H ; ZERO REGISTERS MVI C,00H ; ; ; GET PARAMETERS - SET 16 BIT FLAG IN B IF EITHER IS 16 BITS LONG ; CALL INPARM ; GET FIRST PARAMETER TO BE COMPARED JNC C1 ; IF CARRY FLAG IS SET, SET MVI B,ON ; 16 BIT FLAG IN REG B C1: XCHG ; MOVE VALUE OF FIRST PARM INTO HL CALL INPARM ; GET SECOND PARAMETER JNC C2 ; IF CARRY FLAG SET, SET MVI B,ON ; 16 BIT FLAG IN REG B. ; ; 8 BIT PROCESSING ; C2: MOV A,L ; COMPARE L AND E CMP E RAL ; PUT CARRY BIT IN LOW ORDER BIT OF ACCUM MOV C,A ; SAVE CARRY IN C JNZ C3 ; IF ZERO SET ZERO FLAG AND BYPASS CARRY CHECK LDA FLAGS ORI ZFLAG STA FLAGS JMP C65 C3: CALL CSUBR1 ; ; IF BOTH VALUES ARE 8 BITS END PROCESSING ; C65: MOV A,B ; B = 16 BIT FLAG CPI ON ; IF FLAG ON? JNZ CEND ; IF NOT, END PROCESSING ; ; 16-BIT PROCESSING C7: MOV E,D ; MOVE D TO E AND H TO L TO SET UP MOV L,H ; UP FOR SUBROUTINE CALL MOV A,L ; COMPARE H & D CMP E JZ CEND ; IF EQUAL THEN THE MINUS AND ZERO FLAGS ALREADY HAVE ; BEEN SET IN 8 BIT COMPARE. RAL ; PUT CARRY BIT IN LOW ORDER BIT OF ACCUM. MOV C,A ; SAVE CARRY IN C LDA FLAGS ; GET FELIX FLAGS ANI OFFZ ; TURN OFF ZERO FLAG IF SET IN 8 BIT COMPARE STA FLAGS CALL CSUBR CEND: RET ;** ; ; COMPARISON SUBROUTINE ; ; SETS MINUS FLAG IF SECOND OPERAND GREATER THAN FIRST ; ;** CSUBR1: MOV A,B ; IF 16 BIT PROCESSING, SIGNED ROUTINE MUST CPI ON ; BE IGNORED DURING 8 BIT COMPARE JZ C4 CSUBR: LDA RTSW ; IF SIGNED NO. (IF ON), THEN MUST CPI ON ; CHECK SIGNS. JNZ C4 ; ELSE BYPASS SECTION. ;** ; SIGNED NUMBER SPECIAL ROUTINE ; PUSH B ; SAVE REGISTERS MOV A,E ; TURN OFF ALL BUT SIGN BIT IN E ANI 80H ; MOV C,A ; SAVE IN C MOV A,L ; TURN OFF ALL BUT SIGN BIT IN H ANI 80H CMP C ; COMPARE TWO SIGNS POP B ; RESTORE BC MOV A,C ; LOW BIT OF C CONTAINS CARRY JZ C4 ; IF UNEQUAL COMPLEMENT CARRY RAR ; PUT CARRY BACK CMC ; COMPLEMENT CARRY JMP C5 C4: MOV A,C ; LOW BIT OF C CONTAINS CARRY RAR C5: LDA FLAGS ; GET FELIX FLAGS JNC C55 ; IF CARRY, SET MINUS FLAG ORI MFLAG ; SET MINUS FELIX FLAG JMP C6 C55: ANI OFFM ; TURN OFF MINUS IF SET IN 8 BIT COMPARE C6: STA FLAGS ; RETURN FELIX FLAGS RET ;****************************************************************************** ; ; ADD/SUB * ADD AND SUBTRACT ROUTINE * JANE KIENINGER ; * 1/79 * VERSION 1.1 ; ; DESCR: THIS ROUTINE ADDS THE FIRST PARAMETER TO THE SECOND, OR ; SUBTRACTS THE SECOND FROM THE FIRST, AND PLACES THE RESULT ; IN THE THIRD. THE ENTRY POINT INTO THIS ROUTINE DETERMINES ; WHETHER IT WILL ADD OR SUBTRACT. A ROUTINE FLAG (RTSW) IS SET TO ; 00 FOR ADD AND FF FOR SUBTRACT. THE ROUTINE USES INPARM AND OUTPRM ; FOR INPUT AND OUTPUT OF PARAMETERS AND SETS FELIX FLAGS. THE ; MINUS FLAG IS SET BASED ON THE 16 BITS OF THE RESULT EXCEPT WHEN ; BOTH PARAMETER VALUES ARE 8 BITS (AS INDICATED BY THE CARRY FLAG ; SET BY INPARM), WHEN THAT OCCURS THE MINUS FLAG IS SET BASED ; ON AN 8 BIT RESULT. ; INPUT: REGISTERS D AND E FROM INPARM ; OUPUT: REGISTERS D AND E FOR OUTPRM AND FELIX FLAGS: ZERO (BIT 6), ; MINUS (7), CARRY (1), OVERFLOW (3) ; SUBROUTINES: INPARM, OUTPRM ; REGISTERS DESTROYED: ALL ; ;****************************************************************************** ORG 53E0H ; ; ADD ROUTINE START POINT ; ADDIT: XRA A ; SET ROUTINNE SWITCH TO 0 TO INDICATE STA RTSW ; ADD ROUTINE. JMP A1 ; ; SUBTRACT ROUTINE START POINT ; ORG 53F0H SUBIT: ORI ON ; SET ROUTINE SWITCH TO FF TO INDICATE SUBTRACT STA RTSW ; ROUTINE. ; ; BEGIN ; A1: LDA FLAGS ; ZERO FLAGS AND REGISTERS. ANI ZAPALL STA FLAGS ; MVI C,00H MVI B,00H ; ; GET PARAMETERS - SET 16 BIT FLAG IN REG B IF EITHER IS 16 BITS LONG ; CALL INPARM ; 1ST PARAMETER PLACED IN DE JNC A5 ; IF CARRY FLAG SET, SET MVI B,ON ; 16 BIT FLAG IN REG B A5: XCHG ; 1ST PARAMETER NOW IN HL CALL INPARM ; 2ND PARAMETER IN DE JNC A10 ; IS CARRY FLAG SET, SET MVI B,ON ; 16 BIT FLAG IN REG B ; ; 8-BIT PROCESSING ; A10: LDA RTSW ; IS THIS ADD OR SUBTRACT ROUTINE? CPI ON ; IF NOT ON THEN ADD ELSE SUBTRACT JNZ A15 ; * * 8 BIT SUBTRACTION * MOV A,L ; SUBTRACT LOWER 8 BITS (E & L) SUB E ; STA RESULT ; STORE 8-BIT RESULT PUSH PSW ; SAVE RESULTS AND FLAGS FOR LATER USE MOV A,B ; IF 16 BIT PROCESSING, SKIP 8 BIT FLAG SETTINGS CPI ON LDA RESULT ; ACCUMULATOR MUST CONTAIN RESULT FOR OVERFLOW ; SUBROUTINE. JZ A31 CALL SOVFLOW ; SET 8 BIT OVERFLOW FLAG IN REG C IF NEC. JMP A20 ; BYPASS ADD ROUTINE. * * 8-BIT ADDITION * A15: MOV A,L ; ADD LOWER 8 BITS (E & L) ADD E ; STA RESULT ; STORE 8 BIT RESULT PUSH PSW ; SAVE RESULTS AND FLAGS FOR LATER USE MOV A,B ; IF 16 BIT PROCESSING, SKIP 8 BIT FLAG SETTING CPI ON ; LDA RESULT ; ACCUMULATOR MUST CONTAIN RESULT FOR OVERFLOW ; SUBROUTINE. JZ A31 ; CALL OVFLOW ; SET 8BIT OVERFLOW FLAG IN REG C A20: POP PSW ; RECOVER RESULT AND FLAGS MVI A,ZERO ; CLEAR ACCUMULATER (MUST USE MVI) JNC A25 ; SET CARRY FLAG TEMPORARILY IN A MVI A,CFG ; IF CARRY SYSTEM FLAG SET A25: JP A30 ; SET FELIX MINUS FLAG TEMP WITH 8 BIT ORI MFLAG ; CARRY FLAG IN A IF RESULT WAS NEGATIVE A30: ORA C ; ADD OVERFLOW FLAG TO CARRY AND MINUS MOV C,A ; SAVE ALL FLAGS IN C LDA FLAGS ; BRING IN FELIX FLAGS ORA C ; SET 8-BIT OVERFLOW, CARRY AND MINUS PERMANNENTLY STA FLAGS JMP A60 ; SKIP TO SET ZERO FLAG ; ; 16 BIT PROCESSING ; ; A31: LDA RTSW ; IF THIS ADD OR SUBTRACT ROUTINE ? CPI ON ; IF NOT ON THEN ADD ELSE SUBTRACT JNZ A35 ; * * 16 BIT SUBTRACTION * POP PSW ; RESTORE CARRY FLAG A32: MOV A,H ; SUBTRACT TOP 8 BITS (H & D) WITH BORROW FROM SBB D ; LOWER 8 BITS. MOV E,D ; MOVE D TO E AND H TO L TO PROPERLY USE MOV L,H ; OVERFLOW ROUTINE. PUSH PSW ; SAVE RESULT AND SYSTEM FLAGS CALL SOVFLOW ; SETS OVERFLOW FLAG IN C IF ANY JMP A38 ; BYPASS ADD ROUTINE * * * 16 BIT ADDITION * A35: POP PSW ; RESTORE CARRY FLAG A36: MOV A,H ; ADD TOP 8-BITS (H & D) WITH CARRY FROM ADC D ; LOWER 8-BITS. MOV E,D ; MOVE D TO E AND H TO L TO PROPERLY USE OVERFLOW MOV L,H ; ROUTINE. PUSH PSW ; SAVE RESULT AND SYSTEM FLAGS. CALL OVFLOW ; SETS OVERFLOW FLAG IN REG C (IF ANY) A38: POP PSW ; RESTORE RESULT IN ACCUMULATOR AND ALL SYSTEM FLAGS MOV D,A ; SAVE RESULT OF FUNCTION IN D MVI H,00H ; CLEAR H JNC A40 ; SET CARRY TEMP IN H IF SYSTEM MVI H,CFG ; CARRY WAS SET A40: LDA FLAGS ; BRING IN FELIX FLAGS JP A45 ; IF RESULT WAS NEGATIVE SET MINUS FLAG ORI MFLAG ; PERMANENTLY. JMP A50 ; A45: ANI OFFM ; IF RESULT WAS POSITIVE RESET FLAG A50: ORA C ; SET 16 BIT OVERFLOW FLAG PERMANENTLY ORA H ; SET 16 BIT CARRY FLAG PERMANENTLY STA FLAGS ; RETURN FELIX FLAGS TO MEMORY ; ; SET ZERO FLAG ; A60: LDA RESULT ; READ IN 8 BIT PROCESSING RESULTS MOV E,A ; STORE THIS RESULT PERMANENTLY IN E ORA D ; COMPARE IT WITH 16-BIT RESULTS JNZ A65 ; IF RESULT = 0 SET ZERO FLAGS LDA FLAGS ; ORI ZFLAG ; STA FLAGS ; RETURN FELIX FLAGS TO MEMORY FOR LAST TIME A65: CALL OUTPRM RET ; ; OVFLOW * OVERFLOW SUBROUTINE FOR ADD * ; ; DESCR: THIS SUBROUTINE SETS THE FELIX OVERFLOW FLAG IF BOTH OPERANDS ARE ; THE SAME SIGN AND THE RESULT IS OF THE OPPOSITE SIGN. THE CODING HAS ; THE ORDER OF THIS REVERSED FOR EFFICIENCY. AT THE END OF THE ; ROUTINE REGISTER C CONTAINS AN 8 BIT OVERFLOW FLAG CONFIGURATION. ; REGISTERS: REG A - RESULT OF ADDITION (INITIALLY ONLY) ; REG E - SECOND OPERAND ; REG L - FIRST OPERAND ; REG C - ALL ZEROS OR 8 BIT OVERFLOW FLAG CONFIGURATION ; (AT END OF SUBROUTINE) ;;; ; 1. COMPARE SIGN BITS OF RESULT (A) WITH OPERAND IN E. IF = THEN ; NO OVERFLOW. ; OVFLOW: ANI 80H ; TURN OFF ALL BUT SIGN BIT IN RESULT MOV C,A ; SAVE THIS MOV A,E ; NOW BRING IN OPERAND IN E AND TURN OFF ANI 80H ; ALL BUT SIGN BIT. CMP C ; COMPARE SIGN BIT OF RESULT WITH OPERAND FROM E JZ F15 ; IF SIGNS ARE EQUAL THEN NO OVERFLOW ; ; 2. NOW COMPARE SIGN BIT OF OPERAND FROM E WITH THAT OF L. ; MOV C,A ; SAVE E'S SIGN MOV A,L ; BRING IN L AND TURN OFF ALL BUT SIGN BIT ANI 80H ; CMP C ; COMPPARE SIGN BIT OF E WITH L JNZ F15 ; IF EQUAL SET OVERFLOW FLAG TEMPORARILY MVI C,OFG ; IN C. JMP F20 ; BYPASS CLEARING C. F15: MVI C,00H ; CLEAR C FOR FLAG USE F20: RET ; ; SOVFLOW * OVERFLOW SUBROUTINE FOR SUBTRACT * ; ; DESCR: THIS SUBROUTINE SETS THE FELIX OVERFLOW FLAG IF THE SIGNS ; OF THE OPERANDS DIFFER AND THE RESULT SIGN IS THE SAME AS THE ; SIGN OF THE SECOND OPERAND. THE CODING HAS THE ORDER OF THIS ; REVERSED FOR EFFICIENCY. AT THE END OF THE ROUTINE REGISTER C ; CONTAINS AN 8 BIT OVERFLOW FLAG CONFIGURATION. ; REGISTERS: REG A - RESULT OF SUBRACTION (INITIALLY ONLY) ; REG L - FIRST OPERAND ; REG E - SECOND OPERAND ; REG C - ALL ZEROS OR 8 BIT OVERFLOW FLAG CONFIGURATION ; AT END OF SUBROUTINE. ; ; 1. COMPARE SIGN BITS OF RESULT (A) WITH OPERAND IN E. IF UNEQUAL ; THEN NO OVERFLOW. ; SOVFLOW: ANI 80H ; TURN OFF ALL BUT SIGNN BIT IN RESULT MOV C,A ; SAVE THIS MOV A,E ; NOW BRING IN OPERAND IN E AND TURN OFF ANI 80H ; ALL BUT SIGN BIT. CMP C ; COMPARE SIGN BIT OF RESULT WITH OPERAND FROM E. JNZ S15 ; IF SIGNS DIFFER THEN NO OVERFLOW. ; ; 2. NOW COMPARE SIGNS OF TWO OPERANDS ; MOV C,A ; SAVE E'S SIGNN MOV A,L ; BRING IN L AND THRN OFF ALL BUT SIGN BIT ANI 80H ; CMP C ; COMPARE SIGN BIT OF E WITH L JZ S15 ; IF UNEQUAL SET OVERFLOW FLAG IN C MVI C,OFG ; JMP S20 ; BY PASS CLEARING C S15: MVI C,00H ; CLEAR C FOR FLAG USE S20: RET