Saturn V Launch Vehicle Digital Computer (LVDC) Memory Module, measuring 6.5 x 5.75 x 5.25, produced by IBM under NASA contract number NAS 8-11561. The module is a self-contained assembly with memory timing, drive, inhibit and sensing circuits arranged around the core array for use in the LVDC. It has a capacity of 4,096 word locations (28 bits each) of primary storage, and up to eight of these modules could be grouped together for an overall capacity of 32KB. The modules could be operated in either a simplex or duplex mode, as determined by the Memory Control Elements; in simplex, the system utilized its full memory capacity, while duplex mode only used half of the available space but in duplicate to provide redundancy in case of failure. One of the mounting feet is stamped: “S/N 0X, 6111500.” Housed in a Lucite carrying case to prevent corrosion. In fine condition.
These memory modules were used in the LVDC, which was installed within the Saturn IB and Saturn V Instrument Unit (IU) to support prelaunch checkout; navigation, guidance and attitude control; flight sequence control; and orbital checkout of vehicle systems. This served as the ‘brains’ of the Saturn flight control system and employed the first computer application and architecture in which all critical circuits were triplicated (triple modular redundancy), giving near-ultimate operative reliability. Essential to operations of the Saturn V systems, this LVDC Memory Module is an excellent piece of history associated not only with NASA but with computational innovation as a whole.
