if you use pata hdd then 1 channel can connect 2 ide devices
if you user sata hdd then each channel normally can only connect 1device
we think your hdd should be pata type
normal cheap power supply can connect 4 ide devices
so you no need to worry about that
solution
you go out to buy a pata hdd is ok
320g hdd also have pata version
then you set master/slave in the hdd jumper setting
connect it & format ~> done
it is a very easy job