Picked up an EVK-300!!!

I already had the blank PCB (EVK-100) and had a 3+ year struggle finding anything about it. I found a guy in his mid-80s at the time who had a web site that wasn't touched in 10 years. I emailed him and he had already sent his documentation to a guy in England. That guy gave me a copy of the docs. In the meantime, I found one in the museum back in Mountain View, CA, that never answers emails... and one in a university museum in Stuttgart, Germany. The university folks offered to send me high res photos of their board so I could see all the resistor color codes and try to build mine. After I got the docs I forwarded them to the university and they not only fired up their computer board, but dumped the ROMs and sent me the code.

Now I have the board, code, and build/operation docs, but no S6834 EPROMs or the S6830 PROM with the monitor code. Found 2 MC6834 on eBay a few years back. Nothing since.

Fast forward to joining an e-waste / recycling group on Facebook and a user posted up a slew of white/gold and purple/gold ceramic EPROMs. Zooming in... FIVE S6834 EPROMS! He also had a complete EVK-300. I took a gamble and sent money to him in New Zealand and now have the EVK-300 to go with my blank PCB.

Congratulations! That is a very nice find.

You said you had the documentation, I found the Stuttgart site some time ago that you mention above and they had posted the ROM dumps.

Two computer magazines ran articles on the prototyping boards, these are:
Kilobaud October November, and December 1979
Interface Age January, February, March 1977

I assume you have the Prototyping Board Manual from the Stuttgart site? It had the parts list for the three variants.

You might have to adapt other period EPROMs since the pinout for the S6834s was peculiar to Motorola/AMI and not nearly as popular.

I am not sure if I should be happy that you have a working EVK-300, or sad that you still can't assemble the board. Nice find! I don't think I have ever seen a white ceramic 6800 before.

Vermithrax said:

Two computer magazines ran articles on the prototyping boards, these are:
Kilobaud October November, and December 1979
Interface Age January, February, March 1977

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Thanks! I downloaded those.

I gave them the Prototyping Board Manual. I got it from the English gentleman that scanned the docs that the gentleman in Arizona owned and sent him.

Vermithrax said:

You might have to adapt other period EPROMs since the pinout for the S6834s was peculiar to Motorola/AMI and not nearly as popular.

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The seller was supposed to include 5x S6834 EPROMs, but did include some 1702 and 2708 EPROMs. I contacted him and he's shipping me out the 5 S6834 EPROMs.

I'd still need to adapt something to the S6830 PROM socket.

epooch said:

I am not sure if I should be happy that you have a working EVK-300, or sad that you still can't assemble the board.

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I'm going to collect as many chips as I can and put them in a shadowbox with the sealed PCB for display next to the EVK-300.