Been banging away at code and one of my "clever" tricks doesn't seem to work anymore. I want to check a register file (RAM location) to see if it contains a '0'. So... movf 'register',W btfss STATUS,Z goto reg_not_zero goto reg_zero This does not work under the MPLAB simulator (v4.0.0.14) It always branches to 'reg_not_zero' and the Register Windows indeed shows that 'Z' in STATUS wasn't affected. This is putting a major crimp in my code. I've also tried changing the destination in the first line to 'F' but no help either. RK P.S. Dave, If you're looking at this it was late and I needed an answer right away.