1771 floppy controller questions

From: Richard Erlacher <edick_at_idcomm.com>
Date: Fri Nov 23 09:27:03 2001

Well, it sounds like it's less likely that you'll break the parts in your
tester, but it seems unlikely you'll be able to test the 4116's in it.

I got the mistaken impression that you had the HP test-clip type of IC tester,
of which I have a few, which require a functional component against which to
compare the function of the circuit under test. I've never figured out how
these work, since most of the ones I have are already brokent. One of these days
...

Dick

----- Original Message -----
From: "Tothwolf" <tothwolf_at_concentric.net>
To: <classiccmp_at_classiccmp.org>
Sent: Friday, November 23, 2001 2:21 AM
Subject: Re: 1771 floppy controller questions


> On Thu, 22 Nov 2001, Richard Erlacher wrote:
> > From: "Tony Duell" <ard_at_p850ug1.demon.co.uk>
> >
> > > Most (all?) DRAM testers that I've seen test just the chips/simms out of
> > > the circuit. It makes sense, since that way they can drive the address
> > > lines, RAS/, CAS/, etc and veryify that the RAM works correctly on all
> > > locations, etc.
> >
> > HP made a series of device testers that live on a test clip that you
> > plug on in-situ, and if it's designed for one set of supplies, and you
> > hook up another, you may not be pleased with the results. I've got a
> > few of those out-of-circuit testers, but the one I thing he (Tothwolf)
> > is using is one of the type I'm referring to. It would be a shame to
> > damage one, as it can test a soldered-in part without first
> > unsoldering it.
>
> The tester set I have is designed for out of circuit use. Both units are
> labeled 'ramcheck' and list the manufacturer as Innoventions, Inc.
> Houston, TX. The tester supports 64k and 256k according to the label. I
> opened up the tester, and found it contains an AMD 8088, a 27C32 eprom,
> and a single dram chip, along with a mix of 74LS ttl logic chips. From the
> looks of it, I could modify it to support 1024s and likely support older
> chips if I design some sort of interface board. The speed checker unit is
> designed to be used in-line with the tester (or maybe in circuit?), as it
> has a ribbon cable with dip idc header on one end. It has a knob for
> voltage selection labeled; Off, 4.5V, 5V, 5.5V, NR. I'm not sure what the
> NR stands for, maybe no regulation? The other control is a 16 position
> rotary switch (0-15), which is used x10 for speed selection in ns. Its
> logic board contains a 7805 regulator, a handful of 74LS ttl, and a few
> other chips I'd need to look up in a databook (Possibly a PROM and some
> clock generators?)
>
> -Toth
>
>
Received on Fri Nov 23 2001 - 09:27:03 GMT