26 lines
571 B
Python
26 lines
571 B
Python
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#
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# Please see this video for details:
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# https://www.youtube.com/watch?v=yl8vPW5hydQ
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#
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code = bytearray([
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0xa9, 0xff, # lda #$ff # set output register B
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0x8d, 0x02, 0x60, # sta $6002
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0xa9, 0x00, # lda #$00 # Start at 0
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0x8d, 0x00, 0x60, # sta $6000 # Latch out
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0x69, 0x01, # add #$1
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0x4c, 0x07, 0x80, # jmp $8005 # go back to first output
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])
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rom = code + bytearray([0xea] * (32768 - len(code)))
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# Reset Vector
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rom[0x7ffc] = 0x00
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rom[0x7ffd] = 0x80
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with open("rom-counter.bin", "wb") as out_file:
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out_file.write(rom)
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