All, I have a question for the PIC community that has me stumped at the moment. Here is the scenario. I am using an ispPro programmer from Basic Micro. It works well, and we have used it for a long time. We have a 16F76 in one of our systems. I erased the program memory, and reprogrammed it with different code. At the end of the programming cycle, I get an error that the programmer can't verify location $4000. The top of the address space is $3FFF or at least I thought it was. I looked at the datasheet, but didn't find anything about address $4000. I thought it might be a system location that is only availabe to the device programmer at program time. Does anybody know what is significant about this location? When I do a read, I see location $4000 is $80. When I erase it, it still says $80. It should be $FF if it is truly erased I think. If I reprogram it with the old firmware, I still get the error. It's like the bit is stuck high. It can't be programmed low. Anyway, if anyone has any insight, let me know. I would appreciate it. Thanks and Regards, Jim -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist