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billforsternz / retro-sargon

This is a project to bring the code from the book "Sargon a computer chess program" back to life in the modern era
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sargon-z80.asm has overlapping data #5

Open arpruss opened 2 years ago

arpruss commented 2 years ago

sargon-z80.asm when run through zmac produces two different sets of data at address 0x0180.

Here is the issue as seen in the sargon-z80.lst file in your github:

230: 0173 00000000 DW 0,0,0,0,0,0,0,0,0,0 00000000 00000000 00000000 00000000

2040: 0180 80808080 DB $80,$80,$80,$80 ; Black Pawn on White square

These two areas overlap!

arpruss commented 2 years ago

I checked and the problem occurs in the original scan. There are a few bytes of overlap between the data tables area and the graphics.

billforsternz commented 2 years ago

Thanks for your efforts. I was concentrating on getting move generation and just did enough with the graphics and user interface to get it to assemble, no more. I have an open project that I haven't published on github yet where I polish up the Z80 code with a view to running it on a vanilla CP/M emulation with ASCII graphics. I will tidy this issue up when I get back into that work sometime early in 2022.