Contains 4 mega bytes words of semiconductor memory and a 32 bit word length. The computer interfaces with the i/o devices through a bidirectional i/o bus, using circuitry located in the computer mainframe. The disk drive ia a moving head disk data storage unit. The storage medium consists of multiple magmetic platters which slides out of the cabinet for easy replacement. Tth 9-track reel-to-reel magnetic tape unit consists of drive, control, read and record assemblies. Tape unit supports both 800 and 1600 bpi tape densities