mirror of
https://github.com/a2-4am/passport.git
synced 2024-07-04 19:29:43 +00:00
135 lines
2.9 KiB
Plaintext
Executable File
135 lines
2.9 KiB
Plaintext
Executable File
;-------------------------------
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; CopyMemory
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; in: A = source address (high)
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; X = destination address (high)
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; Y = number of pages to copy
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; out: all flags and registers clobbered
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;-------------------------------
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!zone {
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CopyMemory
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sta .source+2
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stx .dest+2
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ldx #$00
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.source lda $FF00,x
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.dest sta $FF00,x
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inx
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bne .source
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inc .source+2
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inc .dest+2
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dey
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bne .source
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rts
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}
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;-------------------------------
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; ClearMemory
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; in: A = source address (high)
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; X = value to set
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; Y = number of pages
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; out: all flags and registers clobbered
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;-------------------------------
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!zone {
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ClearMemory
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sta .dest+2
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txa
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ldx #$00
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.dest sta $FF00,x
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inx
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bne .dest
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inc .dest+2
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dey
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bne .dest
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rts
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}
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;-------------------------------
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; ClearTSBuffer
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; clear the $1000 byte memory buffer
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; used to store the current track's data
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; in: none
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; out: all flags and registers clobbered
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;-------------------------------
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ClearTSBuffer
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lda #BASEPAGE
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ldx #$00
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ldy #$10
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jmp ClearMemory
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;-------------------------------
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; SwapMemory
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; in: A = source address (high)
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; X = destination address (high)
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; Y = number of pages to copy
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; out: all flags and registers clobbered
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;-------------------------------
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!zone {
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SwapMemory
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sta .source1+2
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sta .source2+2
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stx .dest1+2
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stx .dest2+2
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ldx #$00
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.source1 lda $FF00,x
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pha
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.dest1 lda $FF00,x
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.source2 sta $FF00,x
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pla
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.dest2 sta $FF00,x
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inx
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bne .source1
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inc .source1+2
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inc .source2+2
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inc .dest1+2
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inc .dest2+2
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dey
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bne .source1
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rts
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}
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;-------------------------------
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; SaveProDOS
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; saves memory pages used by ProDOS
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; pages $00, $03, $BF
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; in: none
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; out: all flags and registers clobbered
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;-------------------------------
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!zone {
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SaveProDOS
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lda #$00
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ldx #$40
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ldy #$01
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jsr CopyMemory
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lda #$03
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ldx #$41
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ldy #$01
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jsr CopyMemory
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lda #$BF
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ldx #$42
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ldy #$01
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jsr CopyMemory
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.exit
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rts
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}
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;-------------------------------
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; SwapProDOS
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; saves/restores memory pages used by ProDOS
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; pages $00, $03, $BF
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; in: none
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; out: all flags and registers clobbered
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;-------------------------------
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SwapProDOS
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lda #$00
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ldx #$40
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ldy #$01
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jsr SwapMemory
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lda #$03
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ldx #$41
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ldy #$01
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jsr SwapMemory
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lda #$BF
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ldx #$42
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ldy #$01
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jsr SwapMemory
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rts
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