mirror of
https://github.com/nathanriggs/AppleIIAsm-Collection.git
synced 2024-12-12 01:30:00 +00:00
134 lines
2.8 KiB
Plaintext
134 lines
2.8 KiB
Plaintext
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*``````````````````````````````*
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* ZMLOAD :: RESTORE 0-PAGE MEM *
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*- -*
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* RESTORES PREVIOUSLY SAVED *
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* ZERO PAGE VALUES FROM *
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* HIGHER MEMORY LOCATION. *
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* CLOBBERS: *
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* *
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* FLAGS: ????---- REG: AXYM *
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*- -*
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* CYCLES: ??? *
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* SIZE: *
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*- -*
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* USAGE: *
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* *
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* LDA #>$6A00 *
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* PHA *
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* LDA #<$6A00 *
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* PHA *
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* JSR ZMLOAD *
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*- -*
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* ENTRY *
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* *
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* TOP OF STACK *
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* *
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* LOW BYTE OF RETURN ADDRESS *
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* HI BYTE OF RETURN ADDRESS *
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* LOW BYTE OF SOURCE *
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* HIGH BYTE OF SOURCE *
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*- -*
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* EXIT *
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* *
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* TOP OF STACK *
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* *
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* LOW BYTE OF RETURN ADDRESS *
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* HI BYTE OF RETURN ADDRESS *
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* *
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*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
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*
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ZMLOAD
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*
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** SAVE RETURN ADDRESS
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*
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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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*
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** GET PARAMETERS
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*
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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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*
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** COPY ZERO PAGE TO SPECIFIED
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** NON-ZERO LOCATION (ONLY THE
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** FREE ONES..)
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*
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LDY #2 ; START 2 AHEAD
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LDA (ADDR1),Y ; AND PUT ADDR1
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STA $08 ; AREA LAST
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INY
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LDA (ADDR1),Y
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STA $09
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INY
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LDA (ADDR1),Y
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STA $19
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INY
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LDA (ADDR1),Y
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STA $1E
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INY
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LDA (ADDR1),Y
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STA $E3
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INY
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LDA (ADDR1),Y
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STA $EB
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INY
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LDA (ADDR1),Y
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STA $EC
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INY
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LDA (ADDR1),Y
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STA $ED
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INY
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LDA (ADDR1),Y
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STA $EE
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INY
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LDA (ADDR1),Y
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STA $EF
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INY
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LDA (ADDR1),Y
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STA $FA
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INY
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LDA (ADDR1),Y
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STA $FB
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INY
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LDA (ADDR1),Y
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STA $FC
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INY
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LDA (ADDR1),Y
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STA $FD
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INY
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LDA (ADDR1),Y
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STA $FE
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INY
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LDA (ADDR1),Y
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STA $FF
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*
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** NOW GET ZERO PAGE VALUES
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** FOR SPACE OCCUPIED BY ADDR; RETURN IN X,Y
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*
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LDY #0
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LDA (ADDR1),Y
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TAX
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LDA (ADDR1+1),Y
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TAY
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STX ADDR1
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STY ADDR1+1
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*
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** RESTORE RETURN ADDRESS
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*
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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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*
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RTS
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*
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** DATA
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*
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:RETADR DS 2
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*
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