18 lines
569 B
NASM
18 lines
569 B
NASM
;================================================================================
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; D-Pad Invert
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; runs in NMI, must use minimum possible # of cycles
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;--------------------------------------------------------------------------------
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; Filtered Joypad 1 Register: [BYST | udlr].
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!INVERT_DPAD = "$7F50CB"
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InvertDPad:
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LDA !INVERT_DPAD : BEQ .normal
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.inverted
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LDA $4219
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BIT.b #$0C : BEQ + : EOR #$0C : +
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BIT.b #$03 : BEQ + : EOR #$03 : +
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STA $01
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RTL
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.normal
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LDA $4219 : STA $01
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RTL
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;-------------------------------------------------------------------------------- |