Circuit Module, Air Traffic Control Computer, IBM 9020

This is a circuit module from an IBM 9020 computer. The components on this module were mounted on small ceramic squares, and soldered to a circuit board. IBM caled the technique "Solid Logic Technology." They represent a transition in electronic design from the discrete circuits of an earlier day to the current use of integrated circuits, or silicon chips.

The IBM 9020 was a large, mainframe computer configured for real-time operation and programmed to handle en-route air traffic control functions at about two dozen centers across the continental United States. The 9020 consisted of three standard commercial mainframes, the IBM System/360 Model 50. All three ran in tandem to ensure high reliability. Unlike standard IBM mainframes of the day, the 9020 was programmed to operate in "real time": that is, to compute and generate results as fast as or faster than data were fed into it.

A full system consisted of this computer coupled to air traffic controllers' consoles, with data fed into the system from long-range radar and other ground stations. IBM 9020s were in use at en-route centers from about 1967 through 1997. This system was used at the FAA en-route center in Leesburg, VA.