> Looks like this chip is not fast enough.
Unfortunately, I more-or-less came to that same conclusion myself last night. However, I'm going to continue to play with it a little, to see if I can't find something that works. For instance, instead of sampling the data inside a loop, I'm hoping that maybe I can use one of the higher-level bit-blasting BASIC commands.
I also could go back to a discrete implementation that I'd sketched out earlier.
Also, someone suggested I try using custom software on a PC to sample the data using the parallel port. I know there is a bunch of freeware that lets you use your parallel port as a poor man's logic analyze. I could try going that route as well.