Although I never looked at the prints for one, all of the Cray 1's that I had a chance to examine were not completely circular--there was always a wedge missing. I expect this was almost essential; all of the wiring between circuit cards was on the inside of the circle, and the customer engineers had to be able to get to that wiring. I suspect that the reason Seymour Cray built the machine in the shape he did was that the circuit cards, plus the machined columns that supported and cooled them, were wider than the card connectors. By arranging the card columns in a semi-circle with the connectors on the inside, he could minimize wiring length. ---- John Dykstra jdykstra(a)nortel.com Principal Software Architect voice: +1 651 415-1604 Nortel (Northern Telecom) fax: +1 612 932-8549