AppleIIAsm-Collection/source/disk19_demo_builds_1/T.MIN.SUB.STRCAT
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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STRCAT
PLA
STA RETADR
PLA
STA RETADR+1
PLA
STA :MLEN
PLA
STA ADDR2
PLA
STA ADDR2+1
PLA
STA ADDR1
PLA
STA ADDR1+1
LDY #0
LDA (ADDR1),Y
STA :S1LEN
STA :S1IND
INC :S1IND
LDA (ADDR2),Y
STA :S2LEN
LDA #1
STA :S2IND
LDA :S2LEN
CLC
ADC :S1LEN
STA :S3LEN
BCS :TOOLONG
CMP :MLEN
BEQ :LENOK
BCC :LENOK
:TOOLONG
LDA #$0FF
STA :SOVF
LDA :MLEN
SEC
SBC :S1LEN
BCC :EXIT
STA :SCNT
LDA :MLEN
STA :S1LEN
JMP :DOCAT
:LENOK
STA :S1LEN
LDA #0
STA :SOVF
LDA :S2LEN
STA :SCNT
:DOCAT
LDA :SCNT
BEQ :EXIT
:CATLP
LDY :S2IND
LDA (ADDR2),Y
LDY :S1IND
STA (ADDR1),Y
INC :S1IND ;INC STRING 1 INDEX
INC :S2IND
DEC :SCNT
BNE :CATLP
:EXIT
LDA :S1LEN
LDY #0
STA (ADDR1),Y
LDA :SOVF
ROR A
LDA RETADR+1
PHA
LDA RETADR
PHA
LDY #0
LDA (ADDR1),Y
STA RETLEN
LDA #1
:RLP
LDA (ADDR1),Y
STA RETURN,Y
CPY RETLEN
INY
BNE :RLP
LDA RETLEN
LDY #0
STA (ADDR1),Y
LDX :S3LEN
RTS
:S3LEN DS 1
:S1LEN DS 1
:S1IND DS 1
:S2LEN DS 1
:S2IND DS 1
:MLEN DS 1
:SCNT DS 1
:SOVF DS 1