54 lines
942 B
ArmAsm
54 lines
942 B
ArmAsm
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; loader
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; A very simplistic code loader designed to manage
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; GS code under ProDOS 8 (if it's good enough for Will Harvey...)
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;
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; Created by Quinn Dunki on 7/29/17
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;
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.org $800
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main:
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NATIVE
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; Copy main code that ProDOS 8 loaded into bank 2.
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; Bank 2 is our "main" code bank because the GS fast
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; graphics path really messes with banks 0 and 1.
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; ProDOS 8 doesn't know anything about non-zero banks
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; though, so things get loaded here and moved.
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mainCopyStart:
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ldx #0
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lda #mainBank2
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sta mainCopyDest+1
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mainCopyLoop:
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lda mainBank2,x
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mainCopyDest:
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sta $020800,x
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inx
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cpx #endMainBank2-mainBank2
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bne mainCopyLoop
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; Set up a long jump into bank 2, and
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; a way for game code to get back here to exit
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; properly to ProDOS 8
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lda #returnToProDOS
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sta proDOSLongJump
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lda #mainBank2
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sta mainLongJump
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jml (mainLongJump)
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returnToProDOS:
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SYNCDBR
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EMULATION
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rts
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mainLongJump:
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.byte 00,08,02
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proDOSLongJump:
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.byte 00,00,00
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