Also don't discount the (really) cheap approach. There is a program
called DigiTrace out there. Basically it turns your parallel port into a
logic analyzer. You just have to build a cable that hooks your port up
to your project. No circuitry involved...just a cable. It's a great
program, and you get some pretty good results considering the price. It
has saved my butt a couple of times at least. The one thing I'm not
exstatic about is that when you exit the program, I think it turns the
port back to outputs, and if your cable is still connected, you can get
some wierd results. That one freaked me out once :) I tried to contact
the author of the program about adding a small buffer that could be
tristated when the program exits, but I have yet to see a response (~1-2
months). Eventually when I find time, I will try to figure out if when
the program is loaded, it happens to toggle some other bit on the
parallel port, which I could then hook to a buffer. If anyone else has
time to do this first, please share :)

This program is windows based. I've only ever run it on win98. The
timing seems to be fairly accurate, it runs through a self calibration
when you start it. If you play with the value you lose timing accuracy,
but you can see more than one iteration of the waveform. Here is a link
for the page: http://www.xs4all.nl/~jwasys/old/diy2.html . I hope
someone else finds this as useful as I do!

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
        -Douglas Adams

> > I am just a home hobbyist (no corporate $$ to help out).
> >
> > I have a background in software and have just started to experiment with
> > microcontroller application development.
> >
> > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
> > cut-it for rapidly changing pins. Does simulation using MPLAB completley
> > eliminate the need for real circuit checking? (I'd be surprised).
>

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