I was in a similar situation. I bought a used SGI Octane, but didn't have the root password and I didn't want to reformat the machine (and didn't have OS discs

I was in a similar situation. I bought a used SGI Octane, but didn't have the root password and I didn't want to reformat the machine (and didn't have OS discs). It ended up being pretty easy to crack the password, though I can't remember the exact process (this was years ago). Once you have physical access, pretty much any security implementation can be defeated.