RE: Using a logic analyzer on vector boards

> > I just picked up a HP 1630D logic analyzer (32 channel 400mhz). It
> cost
> > me somewhere around an arm and a leg :) And now I am wondering if
> anyone
> > here has used a logic analyzer on vector boards. I am thinking
> Atari
> > boards in particular (BZ, Gravitar, Quantum).
>
I've used my Tek on a couple of occasions, but mostly to verify
operation of something else I was hacking in. I find logic analyzers
really handy for debugging stuff I *understand*, but for some random
fault on a vectorboard they can be kinda tough...
>
> > If anyone has used one (on vector or not) I could probably use some
> hints.
>
They're *really* handy for hacking/cracking type endeavors.
Particularly if you have mnemonic disassembly capability and pre-made
processor clips. ;-) Since they can trigger on specific addresses or
data content it's good for telling if code is making it to a certain
point, or even for checking stuff like memory mapped I/O. In my most
recent project I used mine to store only accesses to I/O space on a Z-80
so I could see what addresses were being used to trigger some
encryption...

It also makes a good "multichannel" logic probe. Hook up a few lines to
the inputs of something and use a few more lines to watch the outputs.
Good for learning how complex things interact since you can watch all
the inputs, watch the outputs, and watch intermediate signals as well.

If you have print capabilities just capturing a trace log and printing
it out to look over is nice. Or of you have a game that sort-a runs,
but dies mysteriously they're good for capturing those last milliseconds
before it resets. (The capture buffer usually has a programmable
trigger, so it's easy to trigger on the watchdog reset, but the trace
buffer still "records" all the events leading up to the watchdog
tripping.)

> > All this because I still can't find a cat box. If anyone has one
> for sale
> > in the single leg price range (only have one left) I am really
> interested.
>
Save a foot for the device programmer from me! (Or should I see if
Chris still wants it?)

-Clay
Received on Thu Jul 2 12:09:26 1998