>I suspect what you are seeing is some side-effect related to single stepping. It's >probable that to execute a single step, the PIC actually executes more than one >instruction. Try executing the following sequence at full speed: It does. The single-stepping is accomplished by inserting opcodes into the PIC rather than allowing it to read from the (external) program ROM-emulator. Andy ================================================================== Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA ==================================================================