Dell Dimension 3000 CPU

I have a Dell Dimension 3000 it came with an Intel 80546 Celeron Prescot Destop socket N 320  EO, I would like to upgrade the CPU to a Pentium 3.2 G 800Mhz.  Looking in the manual I see that this PC was available with a Pentium 3.2 800Mhz CPU.  Is this a socket 478 that I need, is the Pentium available in 478, I was told to order a 775 but the old CPU has pins, the 775 has contacts.  Also is there a jumper on the mother board to configure it to 800 Mhz?

Thanks,

rmosca