From what I can remember the PC went on a tray that slotted in one side, the A1200 mb + bottom half of the case wedge into a slot cut in the other side of the case. The only thing that attached the A1200 to anything was a tag that came out half way along the cut-out. The tag had a hole in it so that you could screw through it into the back lip of the A1200's case above the ports. IIRC you also had to make a groove near the top of the A1200's case to get into the cut-out.
