Rare and historic circa 1950s 4-wire core memory plane, featuring a 10 by 15 array with 150 separate ferrite cores hand-wired into the plane. The overall dimensions are 4 1/16″ x 4 1/16″ x 1/4″, and the edge is marked "B16688 88 215" and "Made in Holland." This is an example of core memory using four wires—X, Y, Sense, and Inhibit—as used in very early systems which were primarily dedicated to military and scientific applications; soon after, the separate Sense and Inhibit wires were combined into a single Sense/Inhibit line, making this early four-wire version very rare. The low density of this plane adds to its desirability. It survived the demilitarization destruction process because it was wired in error and never made it into a piece of equipment. There are no machine marks on the mounting holes and the pre-tinned soldier leads were never used, indicating that it was never installed and remains in pristine condition. It was tagged by an engineer “5th Column wired in error” and “Core Plane Not Tested,” meaning that current was never run through it because it failed a visual inspection. Displayed in a Riker box.
The consignor notes that because the memory was considered top secret at the time, the subcontractor did not stamp their logo onto it. He was told that it had to be secretly made outside of the United States due to being produced before patents were awarded. The Soviet Union copied this top secret design in the mid-1960s, not realizing that an updated three-wire system was already in production. Although the Russians were ahead in the space program in the late 1950s, they were over a decade behind in computer technology. This may be the only surviving example of part "B16688 88 215."
Terms and abbreviations used in our descriptions.