IBM AS400?

[compoobah at valleyimplants.com]

Disclaimer: all of this is based on what I heard/found out while looking at getting one

 Not a bad machine, as long as you want to run OS/400 and (generally) program in RPG. IBM never released any information about programming the actual hardware, just the software middle-layer (can't remember what it's called just now). The new machines could possibly be inferred, as they use PowerPC/ RS64 chips, but that may or may not help you because the other logic is undocumented.
     CISC AS/400s are an interesting architecture, no hardware memory protection, it's all taken care of in software.

     BIG GOTCHA- you need to make sure your machine comes with not only the OS, but also the mashine-specific intermediate layer software. Unless you have a friend at IBM, they may be happy to give you a replacement in return for much cash, or they may do the snooty Maitre d' thing . . . and OS/400 is rumored to lock itself after a certain period of inactivity as well.
     In short, it sounded to me like a 50/50 chance of having something cool or a nightmare, so I let the opporitunity slide.