Something I came across today - mpstart will read fuses and ID locations from withon a .obj file, so there's no need to keep setting the fuses each time you load it up. The only problem is that to get mpalc to place data at $2000-2007 you need to use org beyond its defined limits so you get a fatal error for each word of data when assembling. Perhaps ASPIC copes with this OK? I've also descovered a problem when using 16C84s that once in a while they lock up and only a powerdown will start them off again. The reset pin doesn't do anything. It occurs primarily if I use my in-circuit programmer after the chip has already been running. After the programming cycle is complete, the device is presented with a reset pulse but just sits there. If the device is programmed straight after power-up, the reset pulse after programming starts it and it runs the program. Any ideas? All I can think of is that it's latchup on the MCLR pin but I've tried driving it through a resistor, and non of the voltages are outside the supply rails (except the 12V for programming). Any ideas? Thanks, Simon -- ****************************************************************************** * Simon Harrison, University of Newcastle U. Tyne * * * S.J.Harrison@uk.ac.newcastle * Oook * * Fax: 091-222-8180, Attn: S.Harrison * - Librarian * * Telex (Preferred): 53654 UNINEW G, mark 1st line: * * * "TO: S.J.HARRISON (DEPT. OF ELEC. ENG.)" * * ******************************************************************************