Hi again. I figured out why my simple program wasn't working: my programmer was broken. (In order to read/write a location, I would cycle MCLR/Vpp to get the internal PC set to zero, then send Increment PC commands to get to the address I wanted to diddle. Unfortunately, I think I didn't leave MCLR low long enough to reset the PC and so what I thought were consecutive instruction words were actually spread out through memory. I realize that this is a really crufty way to do things, but I was in a hurry. I'm doing it better, and right, now.) Anyway, I'm now trying to read/write the ID and Configuration regs, but not having any luck. The Microchip programming ref says that if you increment the PC up to 0x2000, you'll be looking at the first ID (or config, I forget) reg, but when *I* run the PC up to 0x2000 and do a Read Program Memory command, I get whatever's at 0x0000. I'm not using the Load Configuration command to set the PC directly to 0x2000 because (according to my reading of the manual) you have to send a word to be programmed, and then (presumably) do a Begin Programming command. For now, I just want to read the contents. Can anybody help? (Anybody else notice that the uChip manuals, which at first look pretty good, are actually not very clear on crucial points?) Thanks, --------------------------------------- ----------------------------- dave madden i don't know about your brain, 3-16-19 naka-machi #301 but mine is really ... bossy. musashino, tokyo 180 japan -l. anderson