crowdaddy said:
It is possible, although very hard. Basically, it involves finding a fully functional older mac, or fixing one up until it is fully functional. Then the fun part comes in....
Macs, despite their wonderfulness, are not very expandable. So the major part is installing the parts of the functional mac into a new case. This is challenging, as the mainboard screws will not line up. So what you have to do is make, out of cardboard or a thin piece of wood, a spacer that the mainboard will mount into and then mount into the case. This can be done out of metal as well, although much harder. The spacer should be the same side as the mainboard, and holes will be drilled or punched into it that will line up with the mainboard and with the case, so basically it is an adaptor.
Once the mainboard spacer/mounter is created and the mainboard is fasten into the case, the rest is just a manner of moving the drives and power supply over. The use of drive and power cable extenders might me needed.
The advantage of all this, much more expandability! Where as your old Apple case only had two drive bays and two-to-four internal harddrive spaces, the new case will have up to six drive bays and lots of places to install harddrives.
Plus, you can use really cool cases, like the clear case that is sown below. In that clear case I have: Power Computing Mac clone mainboard, 300 watt power supply, DVD 8x +/- RW burner, internal zip drive, internal jaz drive, pcmcia and camera card reader, and four front usb ports, as well as three internal hard drives. Best computer ever!