Artifact Details


Express computer system

Catalog Number



Physical object





Place Manufactured

Irvine, Calif

Identifying Numbers

Model number Express Foil label inside rear.
Other number A20003258-001 Foil label inside rear.
Serial number 100 Foil label inside rear.


overall: 58 1/2 in x 22 3/4 in x 39 1/2 in


Object is a large metal cabinet. The front door swings open to reveal a half-inch tape drive; magnetic strips secure the door in the closed position. Above the tape drive there is a control panel for the Microdata Express CPU with a key switch, five LED indicators, and five tab switches, some of which are spring loaded and some toggle.

After pulling out the Olivetti drive, it is possible to open the door of the tape drive to reveal two heads, a capstan, and the tape drive hubs. There also two tape tensioners. The tape drive swings out to reveal the tape drive control (three boards held in a slotted card rack). Another circuit board holds the drivers for the motors. Various solenoids, microswitches, and potentiometers provide information about the position of the tensioners and whether reels are installed. The drive control and motor drive boards contain a large number of 14- and 16-pin ICs and are connected together with ribbon cables, and the drive control connects to the processor via a large card-edge connector. The power supply for the drive is located at the very bottom of the swing out chassis. Below the tape drive, there is an Olivetti Series 40 disc drive, model 44B and serial number 5356, on heavy drawer slides. The disc drive has a removable disc and is otherwise completely enclosed. The front of the disc drive has a "LOAD/RUN" switch and four indicator lamps sockets missing their bulbs.

Behind the rear door and located behind the tape drive, there is a card rack holding 14 cards that are 14" high x 12.5" wide x 0.675" deep. One of the cards has a card-edge connector and cable that leads to the tape drive controller. Another card has a ribbon connecter that leads to the Olivetti drive. A power supply with filter fans and a single-phase, three-wire twist-lock power cord and plug is below the drive. Both the Olivetti drive and power supply are accessible below the rear door. The rear door is held closed by two captive-screw locks


Digital computer/minicomputer