Personal Iris IRIX issues and other related questions...

I recently picked up an SGI Personal Iris 4D/35 and I'm struggling to get IRIX installed and working (with emphasis on "working"). I currently have at my disposal a copy of IRIX 4.0.5 and a copy of IRIX 5.3. I've tried installing both, and the installation succeeds in both cases, but neither installation works after install. The symptoms are: IRIX 4.0.5 installs. On reboot I get the typical chatter in the console window (UNIX banners, fsck, "The system is coming up," etc.) after which the screen goes black and stays that way forever and ever. Nothing I do causes any response from the machine. IRIX 5.3 installs. On reboot I get the same chatter as above, after which the screen goes black, except with a red SGI-shaped mouse cursor which I can move around with the mouse. After about 5 seconds the screen turns light blue (the same light blue as the console screen at power-on). At this point I can hit esc to bring up the console, and the characters I type on the keyboard are echoed to it but nothing I do has any effect. Any suggestions? I'm also looking for earlier versions of IRIX to run on this machine -- any good places to find them? Thanks! Josh