Rather than merely endorsing William D's comments, I think I have one or two things to add... 1. The keyboards on our RS/6000s at work look exactly like PS/2 keyboards except there is an ID number printed in the margin of the Num Lock lamp sticker. It does not have the huge quantity of extra keys found on the 3270 workstations that I used to work with. 2. The RS/6000 are not very closely related physically to the 6150 (RT PC) family. Certainly neither our model 320 nor 375 have ISA slots - the slots are much more like the ones you describe. 3. However, I am puzzled by your physical description. I too expected a large tower for a 500 series powerstation. In fact I cannot think of any IBM product that looked like an Apple /// except possibly the Datamaster. Could the name Powerstation have been used for something other than RS/6000s? Philip.