Signedembossed on the plastic end piece of each card: DIGITAL EQUIPMENT CORPORATION / MAYNARD, MASSACHUSETTS
printed in blue and white on a blue and white label on edge of bus: digital / EQUIPMENT / CORPORATION / WESTMINSTER / MASSACHUSETTS
Inscribedtyped and handwritten on a white label on side of bus: Type: M M II S / LOT NO. 08816
embossed on metal plate on side of bus: MM II S / 5964
FunctionAn early 'Q' bus and circuit cards from the Aiken Computation Laboratory at Harvard University.
A bus is a mechanism for communicating information between components of a computer or between computers. This bus is a parallel electric bus with twenty-four card connection ports. A comprehensive discussion of computer buses, their history and functioning is available here.
The twelve cards inserted into the bus are flip-chip style cards. "Flip chip" refers to the style of the circuit connection and soldering that sits on top of the circuit board. It is a space economical development upon standard circuits. These are used to communicate information between computer components. When attached to the bus, these cards can sometimes communicate with each other, or directly with outside mechanisms. A comprehensive discussion of "flip chip" circuitry is available here.
ProvenanceThis bus and accompanying cards were found in the Aiken Computation Laboratory at Harvard University in 1995.