I have had recent experience in this area and thanks to past postings I was able to get it to work. The example I was following is in the MPLAB manual on page 67. At least for the windows version of MPSIM it is wrong. I found that if I left out the "Pins" line the example would work. Hope this helps, Gene. At 02:50 PM 11/24/97 -0500, you wrote: >Sorry to bomb the whole list with an ON topic message.... > >I am trying to simulate a 12C508 program. I tried to setup a pin stimulus file > to toggle the GPIO >port bit GP0 at instruction 15, 25, and 30. I enabled pin stimulus. Can some one > show me how to >correctly set up the stimulus file? I couldn't find anything on the MCHIP web > page or in the 12C5XX >data sheet. > >Much abliged, > >- -Mark > >PS: My wife has a voice operated robotic lawn mower.... > >Wife speaks "The lawn needs mowing." > >Robotic Lawn Mower Speaks "Yes Dear" > > Gene Norris Gnorris@earthlink.net E. Windsor, NJ USA