Intel i2920 IC was Re: Intel Intellec 8 computer?????

From: Dwight Elvey <elvey_at_hal.com>
Date: Tue Dec 7 14:15:57 1999

ard_at_p850ug1.demon.co.uk (Tony Duell) wrote:
>
> Incidentally, the standard 'support package' for the 2920 seems to have
> run on an MDS800. There was the assembler and simulator that ran under
> ISIS, and a board for the Universal Prom Programmer that allowed you to
> blow code into a 2920. I know my UPP only has 'boring' cards, though.
>
Hi
 Just as a warning to any that might have a UPP with this
particular programming card. I was in charge of system
test on these cards. I think that all of the cards that
got out the door were fixed but some may not have been.
The problem was that they used the same circuit as all
the other cards for the voltage regulator. It was a
723 and a darlington pass transistor. The problem was
that the circuit wasn't properly compensated for short
high currents. It would cause the programming pulse to
peak several volts over where it should. It would destroy
the chips ( this is the case of some of the chips I
currently have ). The fix was to add more capacitance
right after the regulator to keep the demand on the
responce a little lower. Anyhow, don't use one
of these boards unless it had the capacitor tacked
on to it.
 Also, Tony, there was an error in the reset circuit that
caused flaky reset on some UPP units ( most that made it to
the field with this problem ). Some units were more sensitive
than others. If you write back I can describe the problem
and what I remember as the fix.
Dwight
Received on Tue Dec 07 1999 - 14:15:57 GMT