AppleIIAsm-Collection/source/diskX_minidisk_A/T.MIN.SUB.MULT16
nathanriggs c8cac53c5e Rev 0.4 updates
Massive updates that changes the way most subroutines are handled. Major bugfixes, various utilities added, started higher-level libraries.
2019-04-26 18:49:10 -04:00

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MULT16
PLA
STA RETADR
PLA
STA RETADR+1
PLA
STA :MLIER
PLA
STA :MLIER+1
PLA
STA :MCAND
PLA
STA :MCAND+1
LDA #0
STA :HPROD
STA :HPROD+1
LDX #17
CLC
:MULLP
ROR :HPROD+1
ROR :HPROD
ROR :MLIER+1
ROR :MLIER
BCC :DECCNT
CLC
LDA :MCAND
ADC :HPROD
STA :HPROD
LDA :MCAND+1
ADC :HPROD+1
STA :HPROD+1
:DECCNT
DEX
BNE :MULLP
LDY :HPROD
LDX :HPROD+1
LDA :MLIER+1
TAX
STX RETURN+1
LDA :MLIER
TAY
STY RETURN
LDA :HPROD
STA RETURN+2
LDA #2
STA RETLEN
LDA RETADR+1
PHA
LDA RETADR
PHA
LDA :HPROD ;24BIT
RTS
:MCAND DS 3
:MLIER DS 3
:HPROD DS 2