>When I fired it up, I still had my 16F84 with a program on it which
>worked (lights blinked, etc.) I have now managed to 'blank' the chip
>so it doesn't do anything!  I have tried a new chip, a 16F84A,
>but still no good.

I cannot help with the software, but just some advice. Be wary of
substituting an 'A' device for an earlier one. In many cases they have a
different programming algorithm designed to speed up the programming. In
most cases this means that an 'A' chip will not program using the algorithm
for the earlier chip. I am not sure if this is the case for the 16F84 &
16F84A, but just a "heads up" to check the respective data sheets, and make
sure.

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