> On Mar 14, 2023, at 2:00 PM, Jonathan Chapman via cctalk
> <cctalk@classiccmp.org> wrote:
>
>> On HP: yes, perhaps. I used one of those back at DEC, in the mid 1980s. Nice
>> machine, but my suspicion is that I'd run into the small memory problem
>> again that plagues me with the Philips/Fluke analyzer I use right now.
>
> We use several HP analyzers around here, all from the 80s. Even the "small"
> ones are 72 channel and more than sufficient for all your old computer needs.
> The big ones have Ethernet and will talk X11 across the network, which is
> super handy. The older models are serial-only, but can print to a ThinkJet
> emulator running on a PC. That's how I made e.g. this capture image:
>
> http://users.glitchwrks.com/~glitch/images/xtide/xt_ide_rev4/read_delay.gif
>
> Before getting my first HP 1650, I had an older Sony/Tektronix that suffered
> from the "not deep enough capture memory" issue. Haven't run into that with
> the HPs yet, especially the big HP 16500 series. I've found that if I'm
> running out of memory depth, I'm probably not hooked up right.
Often that's true. The issue I'm fighting right now is on a baseband data
transfer which occurs at 11k per second, and some of them seem to be getting
messed up. So there are long gaps in between. I only see one or two of them
before memory runs out. It may be what I need to do is unplug the serial link,
which is running with a continuous clock (6 MHz or so), that's probably sucking
up buffer entries.
The analyzer I have is a Philips PM3585 -- 96 channels (though I don't have a
full set of cables and pods), 2k samples. So in theory, with some care and
enough wires unplugged, I should be able to see 100 or 200 cycles of the
problematic transfers. That might just be good enough.
paul
