This is a set of two unused vintage DSI Tunnel Structure part of Univac Plated Wire Memory.Plated wire memory is a variation of core memory.
Plated-Wire Memory used a grid of wires coated with layer of iron-nickelalloy plated onto a circular cross section substrate wire of beryllium copper. The magnetic field normally stored in the ferrite core was instead stored on the wire itself. Operation was generally similar to core memory, with the wire itself acting as the data line, and the magnetic domains providing the individual bit locations defined by address (word) lines running on either side of (and perpendicular to) the data wire.
Plated-wire memory has been used in a number of applications, typically in aerospace. It was used in the UNIVAC 1110 and UNIVAC 9000 series computers, the Viking program that sent landers to Mars, the Voyager space probes, a prototype guidance computer for the Minuteman-III, the Space Shuttle Main Engine controllers, the KH-9 Hexagon reconnaissance satellite, and in the Hubble Space Telescope.
This is a very interisting item. This is a set of two unused still sealed in the original plastic. This is made by Univac. The Univac part number is 751203-00.