This is part of the cabinetry for the Control Data 3800 series mainframe computer, installed and used for many years at the Consolidated Space Test Center, Sunnyvale, California, where it was used in the management of various military space activities. The CDC 3800 was a military version of a general-purpose, commercial mainframe computer.
This computer was in operation at the CSTC from the late 1960s through Operation Desert Storm in 1991.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.