....deck of the orbiter. It has window views through both aft windows and the overhead windows. Hosted by four Sperry Corporation UNIVAC 1100/40 mainframe computers, 15 Perkin-Elmer minicomputers (mostly 8/32s) provide digital images for the windows, interface with the on-board computers, and perform other functions, acting as fancy channel directors for the mainframes29. A motion-base simulator recreates the two forward crew stations, all forward window views, and the heads-up display used in landing. Also hosted by four 1100s, it has 11 minicomputers due to the lesser digital image requirements. The fixed-base simulator not only has to display proper images of the earth and the cargo bay but it also must image the remote manipulator arm and any payloads, thus requiring the power of five of the 8/32s. Supplementing the two primary Mission Simulators is the Shuttle Procedures Simulator. Also called the "Spare Parts Simulator," it was often cannibalized to keep the more critical Mission Simulators running30. In the early 1980s it was scrapped, and a Guidance and Navigation Simulator was built out of its remaining parts. It is used for some part-task training.
....development control, such as the engine controllers from Marshall and the interfaces and selected test software from Kennedy47.
SAIL operators can monitor tests from display control modules connected to the interface unit. The consoles have color monitors and individual processors used for fault detection. Aside from validating engineering changes and software, the SAIL is used for validating tests to be carried out later on the spacecraft while it is being prepared for flight48.