On 2010-05-08 07:21, Jason White wrote:

 > Hello , recently I have been looking for better pics to
 > expand to. I found one, it looks great...
 > PIC : PIC18F452

No, it doesn look great. It's an old device not recomended
for anyone anymore. The product page at Microchip says
"Please consider this device:  PIC18F4520". You should
follow that advice, or use some even newer device.

 > but there's one problem: it has no internal oscillator...

So just don't use it. Use a modern processor.

 > what would happen if I put a 200MHz oscillator in...

Probably nothing at all.
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