IBM 1410 FPGA Implementation Update - new github repository

Tom Hunter ccth6600 at
Mon May 3 07:15:54 CDT 2021

I think this implementation would give definitive answers to some of the
obscure corner cases which may not be well documented and thus may not be
correctly emulated in software. So even if never implemented on an actual
FPGA this is very valuable.

My Desktop CYBER emulator was implemented in C using the information found
in the CDC hardware manuals. There was one weird CYBER/6000 series console
channel problem which we have been able to resolve using a similar
approach. Paul Koning created a VHDL implementation of a CDC 6400 using
hand written VHDL code for each cordwood module type and "wired" them
together by processing the OCRed wire lists generating more VHDL code. He
used GHDL to execute the VHDL and run some short test code which provided
the definitive answer to the problem. The CDC manuals did not mention this
specific corner case.

Congratulations to Jay for this cool project.

Best regards
Tom Hunter

On Mon, May 3, 2021 at 6:51 AM Chuck Guzis via cctalk <cctalk at>

> That's a very ambitious project!   I commend you for your determination
> and thoroughness.
> I am a bit curious, however.   How does this implementation (other than
> perhaps speed) compare with a software emulation done on a modern CPU?
> --Chuck

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