OT (sortof) wanted items (cart & logic analyzer stuff)

From: Richard Erlacher <edick_at_idcomm.com>
Date: Sat Dec 30 18:44:06 2000

What kind of equipment to you intend to work on with this new LA? I've used
the HP 1630 though it's been about 15 years. It has some nice features.
With today's fairly flexible (I/O) devices, however, you might find it
interesting to build one that uses your PC as a display and acquires the
sample memory contents from the device via the EPP. If you're really
ambitious, perhaps USB would be appealing. It's certainly popular enough.

If you're determined to buy a logic analyzer, the crux of the task is to
find a unit that's not only fully functional but also fully complete. You
need the documentation ... all of it, and you need the complete set of pods
and whatever mechanism, usually an interface board, that is required to
support it. You'll ultimately be disappointed if it's possible to have more
channels than what you've got, so it's important you have enough channel
boards, pods, and probe clips to support them all. There are usually pod
testers that come with a new logic analyzer, and those often are the first
thing that gets lost. Those are extremely necessary when you're having
trouble gettin a setup to work, because they're the only way you have of
restoring your confidence in the instrument. If there's some sort of method
for storing and processing the sample data, either internally or externally,
you certainly will want that capability. A spare pod is pretty useful, too,
unless you think you will find one, which I, having searched the market
pretty thoroughly at various times, doubt very much. I did find on,
however.

I've had several logic analyzers, and, in '92-93, due to the need for
portability, decided to replace my bench-bound model for a portable, a TEK
1240, which is the monochrome (cheaper) version of their portable of the
mid-late '80's. I found any number of incomplete LA's. Mostly, the pods
and the sample boards were partly or completely missing. Documentation was
not common, and, though I found some pods for sale, they were not complete,
and none I was offered had documentation. Unfortunately, it's too easy to
develop excessive or erroneous expectations of what the instrument will do
if you don't have doc's so you'd better have them. I found several
1240/41's for <$250, but those were without pods, several were without the
required sample boards, and none had documentation. I found pods, often
costing more than $250 for a pair, again without documentation and, worse,
without the lead sets and probe clips that you need to attach to a device
under test. I was offered none of the "back-channel" devices, e.g. GPIB,
RS-232 interface, or printer port, (TEK made one for the then-current EPSON
printers). Finally I settled on a pretty complete one costing $1000.
Though I've seldom been required to use it, I've had no reason (so far) to
cuss it, and the only complaint I have is that there are never enough probe
clips, and they always seem to get lost. They turn up again, but I have 150
or so of them, yet when I get anywhere near the 63 channels my logic
analyzer supports, I've resorted to some "alternative" attachment scheme for
some of the signals. That's not always pleasant.

Before you buy, be ceratin that YOUR preferred triggering methods are
supported. I've found triggering the most critical problem of logic
analyzer application, and if there's even a single conceivable mode that
isn't supported, THAT's the one you'll need, ... trust me.

Dick

----- Original Message -----
From: "Dave McGuire" <mcguire_at_neurotica.com>
To: <classiccmp_at_classiccmp.org>
Sent: Saturday, December 30, 2000 2:51 PM
Subject: Re: OT (sortof) wanted items (cart & logic analyzer stuff)


> On December 29, Jay West wrote:
> > I love my HP 1631D logic analyzer, but it takes up way too much real
estate
> > on my bench. I'd like to get a mobil cart for it, but virtually all the
> > scopecarts I've seen (like the tek 200) are for small scopes & such...
the
> > 1631D analyzer is 16.5 inches across the middle, and 17 inches across
the
> > front (the bezel sticks out a bit on each side). Would anyone have a
scope
> > cart (like a tek 212 or similar) that is for wider instruments that is
> > excess and would consider selling/trading?
> >
> > Second, I'm looking for various disassemblers for the 1631D... these
came on
> > 3.5 floppy, but I'm not sure what all disassemblers were available for
it.
> > Anyone got this software laying around?
>
> I didn't think the 1631D had a floppy drive...? I had an HP 54201
> oscilloscope for a while; it was my understanding that the 1631D was
> basically a 54201 scope with an additional logic analysis module.
>
> I've been shopping around off & on for a new logic analyzer...would
> you recommend the 1631D?
>
> -Dave McGuire
>
>
Received on Sat Dec 30 2000 - 18:44:06 GMT