mirror of
https://github.com/nathanriggs/AppleIIAsm-Collection.git
synced 2024-12-12 01:30:00 +00:00
ad58479739
- major bugfixes, especially in 2D arrays - separated each subroutine into own file - reconfigured arrays to use 1-based indexing - Arrays.demo uses macros now - added overflow error handling to get and put routines
107 lines
2.3 KiB
Plaintext
107 lines
2.3 KiB
Plaintext
AGET81
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PLA
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STA RETADR
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PLA
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STA RETADR+1
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PLA
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STA :IDX
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DEC :IDX
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PLA
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STA ADDR1
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PLA
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STA ADDR1+1
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LDA #0
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STA :IDX+1
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LDY #1 ; ELEMENT SIZE LOC
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LDA (ADDR1),Y
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STA :ESIZE
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STA RETLEN ; LENGTH OF RETURN VALUE
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DEY
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LDA (ADDR1),Y
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STA :ALEN
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LDA ERRCTRL
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CMP #1
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BEQ :CHKERR
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JMP :ERREND
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:CHKERR
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LDA :IDX ; IF IDX > ARRAY LENGTH
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CLC
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ADC #1
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CMP :ALEN
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BCS :OVF
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JMP :CHKCONT
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:OVF
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_ERR :E_SID;:E_OVF1;:E_DUMP;:RES;#6
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:CHKCONT
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LDA :IDX
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CMP #255 ; NO ZERO INDEX
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BEQ :UNF ; UNDERFLOW
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JMP :ERREND
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:UNF
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_ERR :E_SID;:E_UNF;:E_DUMP;:RES;#6
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:ERREND
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LDY #0
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LDA #0
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TAY
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STY SCRATCH
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BEQ :ENTLP
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:DOADD
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CLC
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ADC :IDX
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TAX
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TYA
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ADC SCRATCH
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TAY
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TXA
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:LP
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ASL :IDX
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ROL SCRATCH
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:ENTLP
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LSR :ESIZE
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BCS :DOADD
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BNE :LP
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STX :IDX
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STY :IDX+1
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CLC
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LDA #2
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ADC :IDX
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STA :RES
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LDA #0
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ADC :IDX+1
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STA :RES+1
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CLC
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LDA :RES
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ADC ADDR1 ; LOW OF ARRAY ADDRESS
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STA :RES
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LDA :RES+1
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ADC ADDR1+1
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STA :RES+1
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LDY #0
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LDA :RES
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STA ADDR1
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LDA :RES+1
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STA ADDR1+1
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:LDLOOP
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LDA (ADDR1),Y
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STA RETURN,Y
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INY
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CPY RETLEN
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BCC :LDLOOP ; IF .Y <= RETLEN
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BEQ :LDLOOP ; KEEP LOOPING
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LDA RETADR+1
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PHA
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LDA RETADR
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PHA
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LDY :RES
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LDX :RES+1
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LDA RETLEN
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RTS
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:RES DS 2
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:IDX DS 2
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:ESIZE DS 1
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:ALEN DS 1
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:E_SID ASC "AGET81 (GET81 MACRO)",00
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:E_DUMP ASC "DUMPING RES(2) IDX(2) ESIZE(1) ALEN(1)",00
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:E_OVF1 ASC "OVERFLOW: INDEX HIGHER THAN ARRAY LENGTH",00
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:E_UNF ASC "UNDERFLOW: CANNOT USE A ZERO INDEX",00
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