Ok, I left it idle for 5 minutes with TeachText open. I come back to type and the mac is 100% locked up. So its not the SCSI HD that tests fine in other macs. (As the only drive in a IIcx)

Edit: I left it idle once again, moved the mouse, and the screen went all garbled and the mac emitted a horrifying buzzing noise, then promptly reset itself as if nothing even happened.