Sigma Electronics Systems Display Generator 5564

tony duell ard at
Fri Mar 6 00:07:10 CST 2015

> Cool find!

I think I rescued it about 25 years ago, as it looked interesting. It then got somewhat hidden in my old house and
has turned up in the move. Fortuantely [1] my new house is mine alone so I can put classic computers everywhere

[1] Don't take that the wrong way. I wish my parents were still alive, I think of them every day. But living in
their house meant I had to (very reasonably) go with their rules. 

> One of the full-width cards is something like 'area fill'. So it does that in hardware too?
> Yes, probably, it is not that big trick (in theory). Example Amiga's custom chipsets was capable for area fill (line 
> mode), and btw, prototype of that custom chip set was made from TTL chips:
> /ckb/secret/cbm-lorraine-portrait.jpg

Sure. My guess is that the line drawing on this terminal is going to be similar to that on the HP2623. A simple
state machine where the main CPU (in the HP a Z80, in the Sigma a 6800) calculates various parameters and 
the state machine goes along setting pixels. The area fill board is perhaps 50 or so TTL ICs. Not complex
really. But I think it is a high-end feature for a 1970s terminal.

> Please send some photos of that Sigma's miracle!

Will do. 


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