Hello List, Anybody knows or has a PICC test program about how to use the Interrupt service routine in PIC16F877 ....even a very simple program will be helpful. thanx in advance. Regards Salah -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads