Hi Ion,

This PIC should work fine on a Flash-Lab board. It's pin for pin compatible with the 877, so assuming the loader firmware is OK, you're not making any changes to the loader firmware (config fuses) before programming it with the loader firmware, it should work.

Make sure to use DEFINE OSC ? and that this matches the loader firmware. If the loader firmware is compiled for a 20MHz osc, then DEFINE OSC 20 should take care of it. If this doesn't match, you will always get this message.