CRAY-2. This machine was about 10 times more powerful than a CRAY-1, and very expensive. In fact, if you owned one, the service package included several CRAY employees being assigned to your site. While they called themselves CRAY Technicians, we called them 'crayons'! The next model (a CRAY-3) or a Y-MP, which is actually just out of camera range here, was a plasma cooled machine. The circuit boards were immersed in a non-conductive fluid. The towers in all three models are circuit card racks, interconnected with wires, none of which were longer than 4 feet. The circular foot-print was a function of keeping the interconnet wires short and therefore the electrical signalling pathways were always shorter, meaning quicker. The ring that forms the base, and actually padded for sitting, are batteries!

Anyway, this photo is from memory lane (circa 1985) and back then it was big deal to have your picture taken in front of a CRAY.

No prize here, but you are correct!

Jim