Yes.  I have done exactly what you describe.
 http://204.233.101.40/robots/brb.html ).  I didn't want to screw around
UVing JW parts all the time, so I used the 16F84 to develop the basic code
and then moved it to a 12C509.

Keep in mind that the stack depth is different so don't use subroutines that
call subroutines (in general) and you should be ok.  Also, if you use a
higher level language, be sure it can compile for the smaller cores.

Dan


>Fellow PICsters:
>
>I do not have a suitable emulator for the 12C508, but I have some and want
>to use them for a project.
>
>PROBLEM:  If I develop the code on a 16C84 (being mindful of the Ports and
>RAM location differences) should the program work if compiled for the
>12C508???