Well, what is nothing. Nothing is not hieroglyphs.

You do realize the 16f628 and the 16f877a have different footprints? Port a.0 on the 16f877a is pin 2 and on the 16f628 it's pin 17. They both are both analog so must be set to digital. I don't think serout setting it to output sets pin as digital.

It would be best if you posted entire code and not snippet.