Soviet Computing Technology?

TSServo asks: "I started wondering about this the other day in one of my more dull moments at work. What was the USSR using for processors and an OS during the cold war and prior? I doubt that any US based company such as Intel had them on their mailing list. They developed some pretty darn sophisticated stuff and had to have been using something. Does anyone have any information on who the Soviet software and hardware tech leaders were, and moreso how this stuff stacked up against our products during that time?"