I am using a Via C3 1Ghz processor, and Im pretty happy with it. Using a Lead Acid accumilator and an SMPS which I designed myself, I was able to run it for 73 minutes. Im running the motherboard without the negative supply(-12,- 3.3 are not connected, and I am using an AT power supply using an 810E board) , so as of now the serial port is inoperable. Does anybody have a circuit diagram for an SMPS? Most of the programming is done, so that I can operate the stepper motors for my robot through the serial port, and because a serial port uses negative voltage (-15V to trigger a 1 I think), I cannot operate the motors.. Has anybody used the Intel PXA-255 for building a robot? Spiderbot is still not ready as of now, lots of modifications yet to be done, shall post the URL soon when I get the time to make a nice site.