Sigma Electronics Systems Display Generator 5564

Johannes Thelen johannesthelen at
Mon Mar 9 15:56:22 CDT 2015

Thanks for photos!

Chip codes seems from 77...79.  It is obvious, it is not mass producted (board type, also serial no. of vector board is 039). Maybe tailor made for some special CAD system?

"Vector Gen" board seems some nice Signetics chips, like weird multiport 8x4-bit ram (82S112), maybe used as some buffer? Top of that same card goes 12-bit bus to 8263 multiplexers (wild guess: 4-bit for each color?).  Also there is  32x8 PROMs (82S23), maybe used as glue logic / sequencer, too small for look up table.

How many 16Kx16 + ALUs board there were? Three? Maybe there is one processor/memory for each color plane...

You have to put that back to live, and make some reverse engineering. It seems to be really exciting machine!

- Johannes ThelenFinland
Before microcomputers blog (Finnish)

> From: ard at
> To: cctech at
> Subject: RE: Sigma Electronics Systems Display Generator 5564
> Date: Sun, 8 Mar 2015 15:53:19 +0000
> > Please send some photos of that Sigma's miracle!
> I have posted a few pictures of the unit and the PCB in it on my flickr account. You can find them here : 
> -tony

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