Cloning Atari's Space Race


I wanted to add Atari's Space Race to my collection. Unfortunately, the only options on Ebay had massive, spidery cracks all over the circuit board and were egregiously overpriced. ($500?!? Just because it's "rare" doesn't make it valuable.) I wonder how many sellers throw away black and white boards when they won't sell for what they wanted when there were buyers who would've picked them up if they were reasonably priced... but I digress.

Since I wasn't going to be finding one on Ebay (I had been searching for several years) I decided to attempt to clone the game. As somebody who's done it twice, I would not recommend cloning a game to anyone, at all. The schematics in the service manual always have unintentional errors that make cloning the game impossible. (I was able to solve many of them myself, but errors in circuits I can't understand, such as the star/asteroid circuits, means I can't figure out how to make the game work.) Furthermore, it is super expensive and takes 40+ hours to wire up, and even more to debug. I have spent over 100 hours debugging this board during Christmas break of 2021 alone.

Despite starting this project in 2018, I still have not finished it, even in 2021. The reason I have not figured it out is that the star/asteroid generation circuit in the Space Race REV-F manual has errors with it that I cannot figure out. I already fixed a couple of issues with the manual using the wrong blanking signal, but that still has not been enough to make the stars move correctly.

Obviously, it must not be impossible to figure out. Adam Smith figured it out for his DICE emulator. I have tried to find a way to contact him to ask what errors he found in the schematic, but have not had success. If anybody knows him and could have him contact me, I would be most appreciative!

Since it has been 3+ years since I've done the majority of the project, I don't have much to say for all the pictures I have of my progress. One thing that is worth mentioning is that I did make an "Atari Video Probe" for this project as described in the Gran Trak 10 Manual to help me troubleshoot. It allowed me to find several issues with the Space Race schematic mixing up inverted and noninverted signals. I guess this writeup will have to just be a picture gallery then. Enjoy!

I will update the redrawn Space Race Schematic on the Redrawn Schematics page when I get Space Race fully working.

Pictures:














Video

This video shows the issues with the star/asteroid circuits. Both starfields are moving left, one is much faster than the other, both are moving too fast, and several stars are 2 pixels high instead of one. The star position also seems to randomly reset halfway across the screen.



This page was published 1/1/2022

This page was last edited 1/5/2022

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