The Cray-1 has 36 power supplies: 20 that supply -5.2 volts, and 16 that supply -2.0 volts. (The weird negative voltages are for ECL, the fast logic family used

The Cray-1 has 36 power supplies: 20 that supply -5.2 volts, and 16 that supply -2.0 volts. (The weird negative voltages are for ECL, the fast logic family used in the Cray.) The bench around the Cray holds the power supplies. Interestingly, the power supplies themselves are unregulated; regulation is done by the motor-generator unit.