As others mentioned the 16C84 and the 16F84 are compatible
and you get the extra storage on the 16F84. As far as the
programmer, which version of SPASM/SPEP are you using? v4.7
supports both parts. If you are using a version earlier than
v4.6 you will probably need to update your programmer's
firmware with a new chip. The upgrade is $39 which includes
new manuals. Again, check your version. The v4.7 software is
available free from Parallax's web site. When you run SPEP, it
shows you all the devices your version currently supports.

   - Tom

At 06:45 AM 12/7/97 EST, you wrote:
>Is the 16F84 a drop-in replacement for the 16C84?
>
>That is to say, I am currently using 16C84's in a product,
>programming them with a PIC16Cxx-PGM from Parallax,
>and using the Parallax assembler.
>
>I want to know if I can switch to 16F84 without updating my
>programmer or assembler..
>
>