I wonder if I haven't damaged by PICs with static somehow:
- 2 of my workhorse aren't programming on breadboard, ZIF adapter or Lab X1.
- 1 new one has the same problems.
- 1 workhorse works, but intermittently.
- and then there's the 18F4550 that just works, on anything.

I've handled all these ICs the same, same surfaces, same work area, nobody else here messing with them.

I must be doing something really dumb on the Lab X1, my configs or osc setting. Thing is, I haven't changed anything, the X1 OSC jumpers are always set at 20 MHz for all my ICs (A12, B12 and C23, J3 is at top position when looking at the X1 properly).

I set the 18F4550 for 1 second blink intervals, and it seems to be keeping time. I also set the 16F877 at 1 second blink intervals, but it seems to be going twice at fast.

Also, the 16F877 take a long time to erase and program; the 18F4550 takes a fraction of that, maybe 25% at max. And it's technically the same code, just the config changes.

Robert