Through a series of events, I've acquired two computer cases with working power supplies and optical drives. THe computers don't actually run. I think thye both have bad hard discs. At any rate, they both have incredibly old processors and motherboards. I also have a spare AGP graphics card and a 128 MB PC-100 DIMM, so I figure I could buy a 100 MHz board and a processor and hard disc and have a functional computer for well under $100. However, I'm not sure what consideration come into play here and how to tell if a particular motherboard will fit in the case properly. Can anyone help me out or point me to a site where I could find this sort of info?