There is no evidence anywhere that this m/board supports the necessary 1.7 core voltage for the processor.
It's also possile that you currect RAM is 66MHz, which would probably not work at the higher 100MHz bus speed required by a PIII.
However, it IS possible to get a PIII 500MHz 2.0v processor in a slot1 package (I know for sure, as I have one on my desk as I speak). So you may be able to look around and find at laest a faster processor. The difference will not be great however, and a new M/board and processor at a significantly faster speed may be the only answer
The current RAM is definitely 100 mhz - all 256 MB (4 slots).
Thanks for the aedvice, but I am only trying to make the best use of the various bits I have !
I am not currently in a position (financially) to be able to upgrade the existing board /CPU + memory. I would really like to find a cheap slot 1 board to fit the 733 in but they seem to be as rare as the proverbial hen's teeth !