New member introduction, questions on HP 21XX series machines, reliability and maintainability

From: Bob Shannon <bshannon_at_tiac.net>
Date: Thu Oct 30 16:08:51 2003

Guy Sotomayor wrote:

<snip>

>>
>
>The HPs use CML (Current-Mode-Logic) which is a little bit strange but
>there are replacement boards available (from dealers and others).
>

Err, thats not exactly correct. Early HP's use CTL logic, like the 956,
etc. Its similar to TTL
but with an uncommited emitter output stage. Logic supplies are +4.5
and -2.


<snip>

>
>There are two 2116Bs on e-bay at the moment. So they are starting to
>show up some. The 2116 has the advantage over say the 2115 in that you
>can put 16K in the base cabinet (the C can have 32K).
>
The 2116 has lost of slots and watts, but, it sucks power at an awesome
rate.

If you want to run the machine often and hard, get a HP 21MX processor
like the 2113. This gives
much more performance, up to 2 mb of RAM, and at less than a third of
the power draw of a 2116.

And I'm a 2116 fan, I have two of them!

2115's are unobtanium, many HP dealers have yet to see one. I've been
collecting HP's for a long
time and I've only seen one. It was quite unpopular because it missed
the cost / performance curve
of the larger and smaller machines of the same class. Its also limited
to 8K words of core.

>
Received on Thu Oct 30 2003 - 16:08:51 GMT