New here, but not to Mac OS. Here's my AMD athlon 1.4 / 512/ 128 ATI 9500 / 80 + 40 / DVR- 104 (stock apple superdrive) in a G4 Quicksilver case. Basically, flipping the front bezel and moving the PS made room for CPU/Ram and allowed the board to be mounted to the door. Case cracks Mac style, but the PS cable had to be extended using an old G4 PS cable. Tight clearance required the big cpu fan/ al. funnel that's force fed from lower fan. (G4 location, mounted backwards) The deadspace between the nice plastic and metal casing is basically pressurized, (not enough free airflow for cpu fan)
I rigged the PC clicky power switch to the G4 button mechanical style and added usb/sound out in the zip bay, with a magnetic door. Oh yeah, clipped white apple LED and re-soldered to the pc power led. It jus sorta hangs out in the right place.
This project required some major Dremel work and lots of Edison-type engineering. Works great. Well, as great as PC's work. Power supply is weak for all the fans, and the superdrive sucks power.
Thought i'd let you all take a look at my work. it's been running good for about 4 months now.
And don't dis it's pathetic specs. it was once an awesome gaming rig built by a guy named Vinny. Now it plays DVD's, iTunes, and still does a bit of gaming on the weekends.