core memory module, planar
Date: circa 1954
Inventory Number: 1997-1-1231
Classification: Core Memory
Maker: Honeywell (1885-present)
Cultural Region:
Place of Origin:
Dimensions:
1.3 × 21.3 × 24.3 cm (1/2 × 8 3/8 × 9 9/16 in.)
box: 5.7 × 27.3 × 21.8 cm (2 1/4 × 10 3/4 × 8 9/16 in.)
Accessories: white slip of paper with maker and instrument information
Description:
The core memory panel is fixed in a rectangular wooden frame with a hole screwed into each corner. The top pane of the wooden frame is painted brown. The inside bottom edge of the frame is serated. There are fifty copper wires pulled taut between the two long edges of the wooden frame. There are forty, longer copper wires pulled taught between the two short edges of the wooden frame. Each wire goes through one of the grooves on the bottom of the serated lower frame edges and attaches to a metal connection pin fixed to the outside edge of the frame. These two sets of wire form a taught wire grid. Loops of copper wire are interlaced diagonally accross the grid such that three wires meet at each intersection node. At each node, a very small ring composed of magnesium manganese ferrite is wrapped around the three intersecting copper wires.
In Collection(s)
Signedprinted in black lettering on white label with instrument: FERRITE CORE MEMORY PLANE 40 x 50 / Honeywell, ca. 1954
Inscribedhand-written on white instrument card: HONEYWELL / First Computer Memory Card From Steve E(illegible). 11 April 1968
etched in black letters in top right-hand corner of instrument: 135
etched in black letters in top right-hand corner of instrument: 135
FunctionThis instrument is used for the storage of data within a computer. Magnesium manganese ferrite (often just called Ferrite) can hold a magnetic field in either of two directions. The metal is thus amenable to binary logic, which is why it is the substance chosen for the core memory rings: 1 and 0 are aligned with the possible magnetic field directions. The copper wires that run through the rings are the means by which a computer "reads" or "sets" the direction of the magnetic field of one of the rings. The core memory communicates with the central processing unit of the computer through connections made with the metal pins around the outside of the wooden frame which are, in turn, attached to the copper wires. Often, panels like this were stacked together to increase the storage capacity of a computer.
Core memory of this type was designed by Jay Forrester while he was working on the Whirlwind Project, to improve the speed and efficiency of computer memory access. Tubes filled with mercury or vacuum tubes were typically used as the memory for older mainframe computers like the ENIAC. While mercury and vacuum tubes could serve the necessary binary function, they were inefficient and took up a lot of space. Whirlwind was a U.S. Navy project aimed mainly at the production of an aircraft simulator for training pilots and bombers.
Click here for a more detailed discussion of the history and the specifications of magnetic core memory.
Core memory of this type was designed by Jay Forrester while he was working on the Whirlwind Project, to improve the speed and efficiency of computer memory access. Tubes filled with mercury or vacuum tubes were typically used as the memory for older mainframe computers like the ENIAC. While mercury and vacuum tubes could serve the necessary binary function, they were inefficient and took up a lot of space. Whirlwind was a U.S. Navy project aimed mainly at the production of an aircraft simulator for training pilots and bombers.
Click here for a more detailed discussion of the history and the specifications of magnetic core memory.
Primary SourcesJay Forrester, "Designing the Future". Lecture given at the Universidad de Sevilla. Sevilla, Spain: 15 December 1958.
Jay Forrester, URBAN DYNAMICS (Cambridge, Mass: MIT Press, 1969).
Jay Forrester, URBAN DYNAMICS (Cambridge, Mass: MIT Press, 1969).
ProvenanceFrom Steve E[illegible]be, 11 April 1968.