I'm using the ICD2 and MPLAB with a PIC18F4523. I was seeing odd behavior while single-stepping, so I created the following, very simple application. void main() { TRISB =3D0b11111101; while( 1 ) { =20 RB1 =3DRC1; } } The only other thing in the file are the Hitech macros to setup the configuration registers. If I let the program run, RB1 follows RC1 as expected. However, if I single step while watching the PORTC register, the debugger only updates the register value when I execute the RB1 =3DRC1 line. When I change the state of the RC1 pin, and choose Refresh from the Special Function Registers view, the value shown for the PORTC register doesn't change. Is this normal behavior? Thanks, David --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .