I am having an intermittent problem with a project
using a PIC77 (should be similar to 74).

When using my ICEPIC emulator it works all week.
When I blow a pic chip it will work, then intermittently
'hang' - the PIC clock appears to stop.  I use a standard
4MHz 3 pin resonator (centre pin to ground).  I am always
clearing the wdt and it is not jumping into a wdt routine.

I am not (knowingly) going to sleep.

If I pull MCLR lo it will naturally restart OK and run for
maybe 30 mins in a test loop and then intermittently hang
again.  The PSU is 5v and is clean.

When I put the ICEPIC back in, it is OK again.

Any pointers would be gratefully received.

Stephen H Alsop, S&S Systems Ltd, UK. Tel: 01909 773399, Fax: 01909 773645
steve@s.ssystems.easynet.co.uk - http://easyweb.easynet.co.uk/~s.ssystems