32 lines
492 B
ArmAsm
32 lines
492 B
ArmAsm
; HARDWARE LOCATIONS
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KEYPRESS = $C000
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KEYRESET = $C010
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KEYSTROBE = $C010
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; on original Apple II/II+
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; read KEYPRESS
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; if bit 7 set, means key was pressed, value in lower 7 bits
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; access KEYSTROBE to clear value and allow another keypress to happen
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; on Apple IIe
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; can read KEYSTROBE. bit 7 is "any key is down"
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; test keyboard
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keyboard:
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ldy #0
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keyboard_loop:
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lda KEYPRESS
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bpl keyboard_loop
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ora #$80
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sta $400,Y
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iny
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bit KEYRESET
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jmp keyboard_loop
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