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A project log for Retro Sargon Chess Computer

This is a retro-computing project whose goal is to put together a platform able to compile and run the original Sargon Z-80 chess code.

davidadkins1davidadkins1 05/24/2020 at 20:400 Comments

4/23/2020

Let me explain. I wondered if it was possible to use the #TRS-80 (#PigFX font 1) graphic characters to build the chess pieces. So I wrote some Z-80 assembly code to print them out (the 'M' is just a separator) through the SCM I/O calls. I printed both white foreground on a black background, and black foreground on a white background:

Then I mapped out the graphic character blocks in a spreadsheet:

I realized they were much like the Jupiter III Wavemate 2x3 graphics. In generating a translation table I discovered the font matched the Sargon black on white chess piece tables exactly. The book, I found, does call them graphic characters. Sometime, somewhere, someone defined these graphic characters and they became an early standard. Good thing, because there is still a problem here... 

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