23 Sep
2011
23 Sep
'11
1:44 p.m.
, IIRC the
2100A used some odd 'Current Transfer Logic' ICs).
The early models of the HP 2100 series used Fairchild CTuL:
Complementary Transistor Micro-Logic. Non-saturating current-mode logic like ECL, using both
PNP and NPN
transistors.
I was going to add that they feel a bit like ECL chips.
I am pretty sure there are some in the 2100A too. I suspect they're
non-tirival to find now, too which could be a problem meaintaining such a
machine.
There are some manauls for the older HP2100 series machines on the
Australian museum site. Some of them include pinouts and brief
chracteristics of the ICs.
-tony