>Hi all. Is it permissable to change an interrupt edge select bit in the >ISR? Yes. I do this on the 16C71x with no problems at all. I would imagine it would work on the 18x that you mentioned. --Andrew _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads