Yes it looks like there is a programable chip for the frequency.
However there is also a GAL or whatever they are called, I guess this it what needs to be changed (or adjusted) to get to the other speeds.
I think the onbourd clock is disabled and the Cat acutally just gives another source for the 32Mhz, I say this as you can move a clip and disable the device.
The bourd also stores some other info like last mode it was in, etc.
It also looks like you can specify the FPU speed too.
There was a chap some time ago here that managed to play around with his and get the other speeds.
