On Sun, Jan 25, 2015 at 02:24:52PM -0800, Stephen Satchell wrote: > > Today's computers don't use clocks derived from 50- or 60-hertz > power-line frequency. The last computer I remember seeing with such a > clock was the IBM System/360. The System/370 used a motor-generator set > for the power supply, so it had to get its real-time clock time source > another way.
The 360/95 and /91 also used 400 Hz from a motor/gen. Water cooled, too. One of my fondest war stories is when the power was turned off for July 4th weekend but the water was left on.
