Hi, I was wondering if anybody else has had any success in using multiple source files with MPLAB. I originally had about 5 source files and then I would link the resulting object files. But I had strange behavior with the interrupts. When an interrupt would occur the W register would decrement by 1 and the status register would then change before I had a chance to save either of them. I have since moved all of the code into one big file and now everything works just fine. To me, having multiple source files is the logical way to do things. Having one huge file is just a pain when it comes to developing or porting it over to the next project. Anyway now that I have it working I probably won't go back, I was just curious if I was doing something wrong. Thanks, Barry