I'm experiencing a weird problem when running my home-built ICD on a 16F877 target with a 20MHz oscillator. I'm seeing unexpected halts at addresses other than at my set breakpoint. When I substitute a 5Mhz oscillator, the halts only occur at my breakpoint.=20 The target board does run properly at either frequency when I burn the code to flash.=20 I am setting the '10-20MHz' selection in the ICD control box when I'm using it at 20MHz. Has anyone else seen this symptom? Am I perhaps missing something simple? Thanks, Bob -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu