5 Mar
2015
5 Mar
'15
10:07 p.m.
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:http://www.floodgap.com/retrobits
/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.
-tony