Hi again-

I'm using the melabs Serial Programmer (2003) which has served me for many years. I agree that it looks like the LVP fuse is being ignored. Is there a way to check its state? Is there an alternative way to set it?

As to the program itself, yes, setting both port B and B.4 high is redundant, but the output is low. That is the problem in a nutshell. Toggling A.0 shows me whether the program is running (which it does not seem to be doing).

Thanks again!