> I just start using Microchip C18.  After a program is compiled, is there anyway to tell how big the code size is and how much RAM the program use?

Look at the .map file, it shows all the blocks created. Program memory
usage is calculated automatically, but you have to calculate ram-usage
yourself.

(if you haven't done it, set "generate map file" in Project/Build
options/MPLINK linker. IIRC it defaults to off)

 - K

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