Command Decoder from the Saturn Rocket Instrument Unit, measuring 8 x 6 x 5, bearing a George C. Marshall Space Flight Center label affixed on one side, “Decoder Assembly, Central Calibration Command, Assy No. 421023-2, Mod No. 4214, DAC Spec. 1A74051-501, Contr. No. DAC-63-342.” The unit has a total of seven connectors, labeled “J1” through “J7.” In fine condition. The Command Decoder functioned to validate the origins and content of data transmissions, or commands, from the ground controllers to the in-flight rocket. When the command telemetry message was received it was sent to the decoder to decode and validate, then transferred on to the data adapter and LVDC for action.
Terms and abbreviations used in our descriptions.