I actually have three SGIs in my office. One is an O2 that I can't get any action out of whatsoever other than it(seemingly) powering on.
The other is an Iris Indigo that I haven't done anything with yet. I does have VGA and 13W3 on the video card, so display isn't a problem. I actually got the computer "in trade" for a G5 Quad(both sort of hypothetical since both were/are asset tagged university property and the SGI shows up on our annual 10K inventory). It doesn't have any HDDs-which I can fix-but I also haven't been able to find a mouse for it. I do at least have the keyboard. The guy who "gave" it to me does at least have the OS install tapes, so if I ever get anything together I should hopefully be able to put a tape drive on it and have it going.
BTW, it is the earlier one with the 3000 processor and the lower end graphics card. I did have a lot of fun reading all the text on the boards, including the "Bill and Ted's(and Keith's) Excellent Machine" followed by the names of the folks who worked on the project and "The Song and Dance Machine" on the graphics card. I miss computer companies having a sense of humor.