Machine Code program

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Machine Code program

Post by mz-80a »

Not sure on this one. Found on a random tape amongst other 80K stuff. Machine code program. Wonder if anyone's seen it before.
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Re: Machine Code program

Post by psmart »

The code contains the title 'KNIGHT's M/C VSN 3.1" so would look like something from Knights Software but with the header name changed. Has a number of PRINTER messages with start/end so perhaps a disassembler?
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Re: Machine Code program

Post by S_U_C »

I believe this to be someone’s attempt at converting KNIGHT'S M/C VSN 3.1 and it contains bugs the obvious one is the paper out error which prints paper out but then is coded to print out part of the “no printer” error message half way though a word.

Also the first 9 bytes have been corrupted with FF 00s as there is a partial LD DE, TITLE opcode followed by CALL $0015, print ASCII message. Opcode FF is RST 38, which jumps to the clock interrupt and reads time routine but why 6 times. Replace with 8 NOPs 00H and a 11H.

The tile message (in ASCII) begins with the clear screen code $16 and then displays "KNIGHT'S M/C VSN 3.1" and the command prompt "]".
There are 9 main single ASCII character options d, E, C, G, L, S, P, M, X in that order but there are another 18 single byte + execute address combinations in the program.

I have attached a 1st draft of as asm file I created, you can work what the options do.
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