Interfacing with HP-HIL

Jon Elson elson at
Fri May 6 10:46:54 CDT 2016

On 05/05/2016 09:40 PM, Lyndon Nerenberg wrote:
> On 2016-05-05 6:47 PM, Mouse wrote:
>> faster, lower power, maybe
>> even cheaper, etc.
> TTL could never claim "lower power" :-)
Hmmm, I don't know.  (Don't remember the earlier part of 
Some discrete transistor implementations were actually 
pretty high power, they ran off 12 V rails or even more.  I 
know some old computer I poked into (SEL 12-bit, maybe) must 
have been using 24 V rails, they had 2 W load resistors on 
the transistor collectors, and the boards were badly burned 
around those resistors!  Some systems use a variant of ECL, 
which of course really burned power, too.


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