Repair methods (was Cromemco 3101/Beehive B150 score)

[Don Y]

William Donzelli wrote:
>> In a sense, hobbyists have been spoiled by the simplicity of connecting up
>> TTL (and before that, RTL and DTL).  Had the industry standardized on ECL,
>> things would be quite a bit more interesting on the design end.
> 
> Yes, like programmiung in Pascal, engineers would need to follow all the
> rules. Some might say that would be a good thing...

Blech.  It's awfully had to do anything *interesting* in Pascal...
If you want to force folks to carry around lots of excess baggage,
why not pick Ada?  :-(

> Anyway, some years ago I did some 100K design, and pretty much if you
> follow all of the rules in the Fairchild book, nearly all of the weirdo
> analog (radio?) problems drop from sight. It actually was not too hard to
> get away with doing a good digital design while not knowing much analog
> theory. You just had to pull out the ruler quite a few times - now how
> long is that trace?

I worked on a 100MHz (doesn't sound like much, 30 years later :> )
CPU in the mid 70's.  The problems I found were all the *different*
ECL families (10K, 100K, MECL III, etc.) plus all the other
cruft to interface the real world to them (4000 series CMOS
for the JTAG stuff, other level translators for the "fast"
stuff).  And, the colossal *power* requirements (>500W for
that CPU alone!).

Of course, with more integration, that wouldn't be as big an issue
(since a good deal of power is expended in the pin drivers).

But, the idea of having to debug with nothing metallic on
one's person (for fear of serious injury) was not something
I looked forward to...

> 100G scared me, so I never did anything with that except get some parts
> and datasheets.