Oops. Forgot to mention in my previous message. I saw
a programmer
the other day that said it supported user defined test inputs to
PLDs. There wasn't any detail, but it sounded like you could use
the thing to set up a set of input data and get the results that come
out of a PLD. This could be much faster than sticking the target
chip on a breadboard and flipping switches and reading LEDs to
compare I/O.
Let's see, (checks bookmarks) it was the Dataman 48Pro.
Unfortunately, it retails for about $1000. Here's a quote from the
blurb: " Dataman 48Pro isn't only a programmer, but also a tester of
TTL/CMOS logic ICs and memories. Furthermore, it allows the
generation of user-definable test pattern sequences for PLD devices."
I have something a bit like that, or at least most of one. It's a unit
that has a 40 pin SIF socket on top. Pin 20 is permanently tied to
ground. The other pins can be switched, under program control to ground,
or to one of 4 or so programmable voltage sources. So you can set Vpp,
Vcc, set pins high or low, etc. It should be able to program or test just
about anything
The problem is that I don't have the computer interface card or software
for it. There is a ribbon cable coming out of it ending in a DC37 plug.
Some of the ICs inside have had their numbers sanded off, which held me
up for about 5 minutes in figuring out what they were. There is a PAL
chip inside, which seems ot be an an address decoder.
I could probably make up a host adapter card, but without software it's
not a lot of use. And since most manufacturers don't release their
programming specs, there's no easy way to write said software.
-tony