Other useful test equipment (was: RE: Scope use...)

From: Richard Erlacher <richard_at_idcomm.com>
Date: Fri Jul 21 20:48:03 2000

That thing was built on several Multibus-I cards with LOTS of parts. Each
channel was sampled with a 4-bit shift-register that fed a half an 8-bit
register and a 4kx4 SRAM (55ns, which, for a 16Kb sram was considered very
fast). The whole thing was over 1100 IC's on 12 cards in three
interconnected MULTIBUS cardcages plus a display circuit and a CPU for
interacting with the "console" terminal port and driving the various
controls. It made me regret I never built a Multibus-I wirewrap card of my
own and to my standards. That would have saved a few cards.

The system was intended for monitoring VME bus signals plus various
additional channel signals for a test system. It was a major pain and I'm
glad I've by now forgotten more than I remember about it. I got the thing
to work failrly well, but by that time had much better ideas for a
2nd-generation device which I was never able to get someone to pay me to
build. I did, however, build VME wire-wrap cards, capable of supporting the
at-that-time relatively new IDC ribbon cable connectors most other cards
wouldn't. It also allowed the use of PGA parts without a multi-K-buck
adapter.

I know a lot more about sampling circuits than I ever wanted to know, yet
still don't think I'd like to build a LA without someone else specifying the
triggering modes. I'd go on forever trying to figure out what was needed
and what was just a whim.

Dick

----- Original Message -----
From: <jpero_at_sympatico.ca>
To: <classiccmp_at_classiccmp.org>
Sent: Friday, July 21, 2000 2:20 PM
Subject: Re: Other useful test equipment (was: RE: Scope use...)


> > Date: Fri, 21 Jul 2000 17:57:51 -0600
> > From: Richard Erlacher <richard_at_idcomm.com>
> > Subject: Re: Other useful test equipment (was: RE: Scope use...)
> > To: classiccmp_at_classiccmp.org
> > Reply-to: classiccmp_at_classiccmp.org
>
> > Back in '80 or so I needed a very wide LA, wider than what I could
afford at
> > the time, so I built one with the 384-bit width that was required. It
was
> > no picnic!
>
> 384bits to log? Whew, that would be big PCB with under a hundred
> ttl ICs or so and tons of sram ics. What was that needed to do that
> logging and what was that project under test hooked up by that
> oddball 384bits logger?
>
> >
> > It might be interesting to revisit such a problem. An old '486 PC
dedicated
> > to that function would almost be worthwhile . . .
>
> What is your propseal logger for this 486 pc idea? I have several.
> :-)
>
> >
> > Dick
> Wizard
>
>
Received on Fri Jul 21 2000 - 20:48:03 BST