Impressive early Multiplexer / DeMultiplexer (MDM) used for testing in the Space Shuttle and Space Station Command and Data Handling system design. The MDM measures 11.5″ x 32.25″ x 8″, weighs 70 pounds, and features a series of 12 “J” ports to one end, two of which are covered with red caps. The top is marked “Engineering Test Only” twice and bears an affixed Autonetics North American Rockwell parts label: “Des. MDM, Ser. No. A007Y, Part No. 11200-507-1, Spec. MC615-0004A, Multiplexer-DeMultiplexer Engineering Model, Mfr. Code 94756.” A torn label affixed to the top is stamp-dated to May 15, 1975. In fine condition, with expected wear and scuffs. The MDM can provide control and data processing, communication control, and mass storage resources to support control and management of onboard functions. MDMs were also used to provide high-reliability embedded control processing and were the main interface to onboard sensors and effectors via analog and discrete inputs and outputs.
From The Peter Gerry Collection.
