Description of Photograph

Photograph of a single plane from a ferrite core memory stack, which were used in LEO III computers as well as others.

Research comments: This is a plane from a ferrite core memory stack. If you zoom in a lot you can see the x and y wires. At each intersection is a tiny ferrite core (toroid). The wires are threaded through the hole in each one. This is one plane and there would have been a stack of them, one for each bit in the machine's word length. It is probably about 6 inches across. I have always wondered who assembled these things. Must have had a very steady hand! This could have been from a LEO III or IIIF since they used ferrite core stores. But other machines used them too. They were largely replaced by solid state memories after LEO III so the timing fits.  As this picture and one of an integrated circuit were together in Peter Bird's collection it might have been part of a comparison of new and old memory tech. (John Page, former LEO commissioning engineer)

Provenance
Collected by Peter Bird as part of his research for his book LEO - The First Business Computer (1994).

Date: Undated [1960s]

Photographer: Unidentified

Physical Description: 1 photographic print; black and white

Archives Hub References: CMLEO/PB/PH/3/68676
PJB/3/3/015

Other References: DCMLEO20190614018
                  
                  
                  
                  


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This exhibit has a reference ID of CH68676. Please quote this reference ID in any communication with the Centre for Computing History.