21 Dec
2007
21 Dec
'07
9:55 a.m.
From: Brent Hilpert <hilpert at cs.ubc.ca>
Subject: Re: The 2N2/256-BSCP [was: Homebrew Drum Computer]
Another approach to discrete flip-flops can be seen at:
http://www.cs.ubc.ca/~hilpert/eec/misc/CasioAL1000Tech/electronics.html
The stacking of multiple inputs into the basic FF structure was another
technique from the discrete days. Helps reduce the amount of gating (and
hence
transistors) required, for instance when making a parallel loaded shift
register or counter, although they were lots of other novel uses. (Some
aspects of logic design were narrowed with the introduction of ICs for the
sake
of standardizing on elements that would fit in packages with limited
connections.)
Very similar to an East German calculator that I am partway through reverse
engineering, a Soemtron 220.
www.soemtron.org/downloads/board10.pdf
http://www.cs.ubc.ca/~hilpert/eec/misc/CasioAL1000Tech/electronics.html
Looks like thees pages might help in that task thanks for the link
Mike.