At 12:54 PM 9/13/99 -0600, you wrote: In response to my prior inquiry, MANY THANKS to all who responded.... Unfortunately, I had to pick one to use, and the best so far in terms of watching what is going on with minimum hardware, learning curve, etc. is COMLITE32 from . Free, runs under windows, and monitors port activity on the same computer--so you can be running your application code, and watching the data going in and out of one or two comm ports on the same machine, in hex. Many of the others ran a very close second, but this one gets my vote. Caveat: It is a beta release, but seems to work fine--so far. kelly William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems &