mirror of
https://github.com/nathanriggs/AppleIIAsm-Collection.git
synced 2025-02-11 01:31:00 +00:00
171 lines
7.0 KiB
NASM
171 lines
7.0 KiB
NASM
*
|
|
*``````````````````````````````*
|
|
* APUT162 (NATHAN RIGGS) *
|
|
* *
|
|
* PLACE A VALUE HELD IN ONE *
|
|
* ADDRESS INTO THE SPECIFIED *
|
|
* ELEMENT IN A 16-BIT, TWO- *
|
|
* DIMENSIONAL ARRAY. *
|
|
* *
|
|
*------------------------------*
|
|
* MULTIPLICATION ADAPTED FROM *
|
|
* WHITE FLAME'S WORK ON *
|
|
* CODEBASE64. LICENSE MAY VARY *
|
|
*------------------------------*
|
|
* *
|
|
* INPUT: *
|
|
* *
|
|
* ZPW1 = SOURCE ADDRESS *
|
|
* ZPW2 = ARRAY ADDRESS *
|
|
* ZPW3 = 1ST DIM INDEX *
|
|
* ZPW4 = 2ND DIM INDEX *
|
|
* *
|
|
* DESTROY: NZCIDV *
|
|
* ^^^ ^ *
|
|
* *
|
|
* CYCLES: 378+ *
|
|
* SIZE: 220 BYTES *
|
|
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
|
|
*
|
|
]ADDRS EQU ZPW1 ; VALUE SOURCE ADDRESS
|
|
]ADDRD EQU ZPW2 ; ARRAY ADDRESS
|
|
]XIDX EQU ZPW3 ; FIRST DIMENSION INDEX
|
|
]YIDX EQU ZPW4 ; SECOND DIMENSION INDEX
|
|
*
|
|
]ESIZE EQU ZPB1 ; ELEMENT LENGTH
|
|
]MCAND EQU ZPW5 ; MULTIPLICAND
|
|
]MLIER EQU VARTAB ; MULTIPLIER
|
|
]PBAK EQU VARTAB+4 ; PRODUCT BACKUP
|
|
]XLEN EQU VARTAB+8 ; X-DIMENSION LENGTH
|
|
]YLEN EQU VARTAB+12 ; Y-DIMENSION LENGTH
|
|
]PROD EQU VARTAB+16 ; PRODUCT OF MULTIPLICATION
|
|
*
|
|
APUT162
|
|
LDY #4 ; {2C2B} LOAD BYTE 4 OF ARRAY
|
|
LDA (]ADDRD),Y ; {6C2B} HEADER TO GET ELEM LENGTH
|
|
STA ]ESIZE ; {3C2B}
|
|
LDY #0 ; {2C2B} LOAD BYTE 0 TO GET
|
|
LDA (]ADDRD),Y ; {6C2B} X-DIMENSION LENGTH LOBYTE
|
|
STA ]XLEN ; {3C2B}
|
|
LDY #1 ; {2C2B} LOAD BYTE 1 TO GET
|
|
LDA (]ADDRD),Y ; {6C2B} X-DIMENSION LENGTH HIBYTE
|
|
STA ]XLEN+1 ; {3C2B}
|
|
LDY #2 ; {2C2B} LOAD BYTE 2 TO GET THE
|
|
LDA (]ADDRD),Y ; {6C2B} Y-DIMENSION LENGTH LOBYTE
|
|
STA ]YLEN ; {3C2B}
|
|
LDY #3 ; {2C2B} LOAD BYTE 3 TO GET THE
|
|
LDA (]ADDRD),Y ; {6C2B} Y-DIMENSION LENGTH HIBYTE
|
|
STA ]YLEN+1 ; {3C2B}
|
|
LDY #0 ; {2C2B} RESET BYTE INDEX
|
|
*
|
|
** MULTIPLY Y-INDEX BY Y-LENGTH
|
|
*
|
|
LDA ]YIDX ; {3C2B} LOAD Y-INDEX LOBYTE
|
|
STA ]MLIER ; {3C2B} PUT IN MULTIPLIER LOBYTE
|
|
LDA ]YIDX+1 ; {3C2B} DO SAME FOR HIBYTES
|
|
STA ]MLIER+1 ; {3C2B}
|
|
LDA ]YLEN ; {3C2B} PUT Y-DIM LENGTH LOBYTE
|
|
STA ]MCAND ; {3C2B} INTO MULTIPLICAND
|
|
LDA ]YLEN+1 ; {3C2B} DO SAME FOR HIBYTE
|
|
STA ]MCAND+1 ; {3C2B}
|
|
LDA #00 ; {2C2B} CLEAR PRODUCT BYTES
|
|
STA ]PROD ; {3C2B}
|
|
STA ]PROD+1 ; {3C2B}
|
|
STA ]PROD+2 ; {3C2B}
|
|
STA ]PROD+3 ; {3C2B}
|
|
LDX #$10 ; {2C2B} INIT COUNTER TO #16
|
|
:SHIFT_R
|
|
LSR ]MLIER+1 ; {6C2B} DIVIDE MULTIPLIER HIBYTE BY 2
|
|
ROR ]MLIER ; {6C2B} ADJUST LOBYTE
|
|
BCC :ROT_R ; {3C2B} IF 0 PUT IN CARRY, ROTATE PRODUCT
|
|
LDA ]PROD+2 ; {3C2B} LOAD PRODUCT 3RD BYTE
|
|
CLC ; {2C1B} CLEAR CARRY
|
|
ADC ]MCAND ; {4C3B} ADD MULTIPLICAND
|
|
STA ]PROD+2 ; {3C2B} STORE 3RD BYTE
|
|
LDA ]PROD+3 ; {3C2B} LOAD PRODUCT HIBYTE
|
|
ADC ]MCAND+1 ; {4C3B} ADD MULTIPLICAND HIBYTE
|
|
:ROT_R
|
|
ROR ; {6C2B} ROTATE .A RIGHT
|
|
STA ]PROD+3 ; {3C2B} STORE IN PRODUCT HIBYTE
|
|
ROR ]PROD+2 ; {6C2B} ROTATE 3RD BYTE
|
|
ROR ]PROD+1 ; {6C2B} ROTATE 2ND
|
|
ROR ]PROD ; {6C2B} ROTATE LOBYTE
|
|
DEX ; {2C1B} DECREASE X COUNTER
|
|
BNE :SHIFT_R ; {3C2B} IF NOT ZERO, LOOP AGAIN
|
|
*
|
|
** NOW MULTIPLY XIDX BY ELEMENT SIZE
|
|
*
|
|
LDA ]PROD ; {3C2B} BACKUP PREVIOUS
|
|
STA ]PBAK ; {3C2B} PRODUCT FOR USE LATER
|
|
LDA ]PROD+1 ; {3C2B} DO SAME FOR HIBYTE
|
|
STA ]PBAK+1 ; {3C2B}
|
|
LDA ]XIDX ; {3C2B} PUT X-INDEX LOBYTE
|
|
STA ]MLIER ; {3C2B} INTO MULTIPLIER
|
|
LDA ]XIDX+1 ; {3C2B} DO SAME FOR HIBYTE
|
|
STA ]MLIER+1 ; {3C2B}
|
|
LDA ]ESIZE ; {3C2B} PUT ELEMENT SIZE
|
|
STA ]MCAND ; {3C2B} INTO MULTIPLICAND
|
|
LDA #0 ; {2C2B} CLEAR MULTIPLICAND HIBYTE
|
|
STA ]MCAND+1 ; {3C2B}
|
|
*
|
|
STA ]PROD ; {3C2B} CLEAR PRODUCT
|
|
STA ]PROD+1 ; {3C2B}
|
|
STA ]PROD+2 ; {3C2B}
|
|
STA ]PROD+3 ; {3C2B}
|
|
LDX #$10 ; {2C2B} INIT X COUNTER TO #16
|
|
:SHIFTR LSR ]MLIER+1 ; {6C2B} DIVIDE MULTIPLIER BY 2
|
|
ROR ]MLIER ; {6C2B} ADJUST LOBYTE
|
|
BCC :ROTR ; {3C2B} IF 0 PUT INTO CARRY, ROTATE PROD
|
|
LDA ]PROD+2 ; {3C2B} LOAD PRODUCT 3RD BYTE
|
|
CLC ; {2C1B} CLEAR CARRY
|
|
ADC ]MCAND ; {4C3B} ADD MULTIPLICAND LOBYTE
|
|
STA ]PROD+2 ; {3C2B}
|
|
LDA ]PROD+3 ; {3C2B} LOAD PRODUCT HIBYTE
|
|
ADC ]MCAND+1 ; {4C3B} HAD MULTIPLICAND HIBYTE
|
|
:ROTR
|
|
ROR ; {6C2B} ROTATE .A RIGHT
|
|
STA ]PROD+3 ; {3C2B} STORE PRODUCT HIBYTE
|
|
ROR ]PROD+2 ; {6C2B} ROTATE 3RD BYTE
|
|
ROR ]PROD+1 ; {6C2B} ROTATE 2ND BYTE
|
|
ROR ]PROD ; {6C2B} ROTATE LOBYTE
|
|
DEX ; {2C1B} DECREASE X COUNTER
|
|
BNE :SHIFTR ; {3C2B} IF NOT 0, KEEP LOOPING
|
|
*
|
|
** NOW ADD X * ESIZE TO RUNNING PRODUCT
|
|
*
|
|
CLC ; {2C1B} CLEAR CARRY
|
|
LDA ]PROD ; {3C2B} ADD CURRENT PRODUCT
|
|
ADC ]PBAK ; {4C3B} TO PREVIOUS PRODUCT
|
|
STA ]PROD ; {3C2B} AND STORE BACK IN PRODUCT
|
|
LDA ]PROD+1 ; {3C2B}
|
|
ADC ]PBAK+1 ; {4C3B}
|
|
STA ]PROD+1 ; {3C2B}
|
|
CLC ; {2C1B} CLEAR CARRY
|
|
LDA ]PROD ; {3C2B} INCREASE LOBYTE BY 5
|
|
ADC #5 ; {2C2B} TO ACCOUNT FOR ARRAY
|
|
STA ]PROD ; {3C2B} HEADER
|
|
LDA ]PROD+1 ; {3C2B}
|
|
ADC #0 ; {2C2B} ADJUST HIBYTE
|
|
STA ]PROD+1 ; {3C2B}
|
|
*
|
|
** ADD ARRAY ADDRESS TO GET INDEX
|
|
*
|
|
CLC ; {2C1B} CLEAR CARRY
|
|
LDA ]PROD ; {3C2B} ADD ARRAY ADDRESS
|
|
ADC ]ADDRD ; {4C3B} TO PRODUCT TO GET
|
|
STA ZPW6 ; {3C2B} ELEMENT ADDRESS; STORE
|
|
LDA ]PROD+1 ; {3C2B} ADDRESS ON ZERO PAGE
|
|
ADC ]ADDRD+1 ; {4C3B}
|
|
STA ZPW6+1 ; {3C2B}
|
|
LDY #0 ; {2C2B} RESET BYTE INDEX
|
|
:CLP
|
|
LDA (]ADDRS),Y ; {6C2B} LOAD BYTE FROM SOURCE
|
|
STA (ZPW6),Y ; {6C2B} STORE AT ELEMENT ADDRESS
|
|
INY ; {2C1B} INCREASE BYTE INDEX
|
|
CPY ]ESIZE ; {4C3B} IF != ELEMENT LENGTH, LOOP
|
|
BNE :CLP ; {3C2B}
|
|
LDY ZPW6+1 ; {3C2B} .Y = ELEMENT ADDRESS HIBYTE
|
|
LDX ZPW6 ; {3C2B} .X = ELEMENT ADDRESS LOBYTE
|
|
LDA ]ESIZE ; {3C2B} .A = ELEMENT LENGTH
|
|
RTS ; {6C1B}
|