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0000 DB FF IN FF
0002 D3 FF OUT FF
0004 C3 00 00 JMP 0000
Tom L
0000 DB FF IN FF
0002 D3 FF OUT FF
0004 C3 00 00 JMP 0000
AltairClone wrote:On an 8800b, the IN 0FFh instruction by itself, while single stepped and stopped where the INP light is on, gives you a live display of the front panel switches on the data LEDs. The LEDs update immediately as you flip switches around. The OUT instruction is not needed.
Mike
AltairClone wrote:I realized the Altair Clone differs from the real 8800 in that the Clone displays the sense switch value read at the start of the INP cycle on the data LEDs. Technically, the Clone should show FF at this point.
Mike
AltairClone wrote:I went in to the code to fix this last week, but the thought of taking away a useful "bug" bothered me. I decided to leave it alone unless someone ever asked about it. Then you came along a week later... :)
Mike
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