AppleIIAsm-Collection/source/d4_math/T.MIN.SUB.MULT16.ASM
nathanriggs 9b12b6fd9b HOUSEKEEPING
- getting ready for major changes for 0.6.0.
- be sure to download the 0.5.0 release to ensure proper functionality, as these rountines will not work together in the SRC or BIN folder during the transition
- Beginning to significantly alter documentation
2019-12-17 17:19:24 -05:00

39 lines
856 B
NASM

]MCAND EQU WPAR1
]MLIER EQU WPAR2
]HPROD EQU WPAR3
MULT16
LDA #0
STA ]HPROD
STA ]HPROD+1
LDX #17
CLC
:MLP
ROR ]HPROD+1
ROR ]HPROD
ROR ]MLIER+1
ROR ]MLIER
BCC :DX
CLC
LDA ]MCAND
ADC ]HPROD
STA ]HPROD
LDA ]MCAND+1
ADC ]HPROD+1
STA ]HPROD+1
:DX
DEX
BNE :MLP
LDA #4
STA RETLEN
LDA ]HPROD+1
STA RETURN+3
LDA ]HPROD
STA RETURN+2
LDX ]MLIER+1
STX RETURN+1
LDA ]MLIER
STA RETURN
RTS