pc for around $800

Just a question: how could a socket 939 processor support DDR2? Does the motherboard have some for built-in thing to do it?

It doesn't - it uses its own expansion slot into which you plug in a card that has some DDR2 dimms and an AM2 socket.

...Atleast, that's how I remember the ASRock boards doing it.

Uh, I think that they made mobos that had ddr1 OR ddr2 slots, kind of like how old boards used to accomidate slot-load and socket-load cpus? Maybe i'm making stuff up though, I don't know.