19 Jan
2004
19 Jan
'04
2:30 p.m.
[...learning
electronics...]
Tssss. Not to discourage you, but a TTL computer with bazillions
of
ICs is not really suited for newbies, although there is plenty to
learn - namely on those nasty aspects like circuit timing, delays,
glitches, noise on power and signal lines. TTL is to a large degree
analog, not digital, circuit development ;-) You might not directly want to start with a monster
like Computer 74
or EGO, but perhaps with a simple ALU/register device: get a 2901
circuit from BG-Micro and play a bit with it (a breadboard with lots
of switches and LEDs is sufficient). And then extend it with a
2909/-10/-11 from the same source and build the micro control for
that toy.
Good advice. Start simple. My first major piece of TTL hackery was a
little toy 4-bit microprocessor; the most complicated single chip used
was a 4-bit ALU whose 74xxx number I forget by now. (Oh, and a chip
which was basically a 16-word static RAM with 4-bit words.) I was
fortunate enough to have a _really_ _nice_ breadboard to work with.
None of this wish-board stuff; it had individual IC sockets with very
nice machined contacts, and the wires had little stackable plugs (a bit
like banana plugs done tiny) on the ends of them. All contacts were
gold-plated. I shudder to think what they cost the University, but
they were _so_ pleasant to use.
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