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20 lines
385 B
NASM
20 lines
385 B
NASM
; test program for user button on Z80 MBC clock board
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; by Andrew Lynch, 6 Jul 2021
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ORG 00100H
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MAIN_LOOP:
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IN A,($70) ; READ USER BUTTON STATUS
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AND %01000000 ; REMOVE ALL EXCEPT USER BUTTON (D6)
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; 0=PRESSED, 1=NOT PRESSED
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JR NZ,MAIN_LOOP ; IF NOT PRESSED TRY AGAIN
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LD A,%00000011 ; TURN ON BOTH USER LEDS
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OUT ($70),A ;
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RET
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end
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