Harvard Mark II final models of relays
Date: 1947
Inventory Number: 1997-1-0243
Classification: Computer Part
Subject:
Maker: Harvard Computation Laboratory (1944 - 1997)
Maker: Howard H. Aiken (1900 - 1973)
Cultural Region:
Place of Origin:
Dimensions:
12 x 60.6 x 4.3 cm (4 3/4 x 23 7/8 x 1 11/16 in.)
Description:
Three relays--a single coil, a latch coil, and a double coil-- are mounted in a metal frame painted black, which sits on a long black masonite base.
The front of each relay is framed in brown or black plastic and has a clear window.
Each piece extends through the rear of frame.
The front of each relay is framed in brown or black plastic and has a clear window.
Each piece extends through the rear of frame.
Signedon frames: THE AUTOCALL CO. / SHELBY, OHIO, U. S. A.
Inscribedon the front of the left frame: TYPE HHA-JS
on the front of the middle frame: TYPE HHA-JL
on the front of the right frame: TYPE HHA-JD
on back: 47
on back: 35
on the front of the middle frame: TYPE HHA-JL
on the front of the right frame: TYPE HHA-JD
on back: 47
on back: 35
FunctionRelays, as electrical switches, were among the primary logical elements of the computer.
Historical AttributesThese relays are models for those used in the Harvard Mark II computer, the second electromechanical calculating machine designed by Howard Aiken.
ProvenanceOn 13 March 1997, this model was picked up from the Howard H. Aiken Computation Laboratory, 33 Oxford Street. The instrument was transferred to the Collection by Edward P. Jackson, Facilities Manager in the Division of Engineering and Applied Sciences. On exhibition in the entrance area adjacent to the IBM Mark I computer on the first floor of the Science Center, Harvard University.