RR Auction Home
Current Auction Is Open For Bidding
Home |Sitemap|Contact Us| Past Auctions  
 How to Bid   Register to Bid   Auctions   Consign   About Us   Featured Lots   Reviews 
Bidder Login
Show Password

New Bidder Registration
Forgot your password?

The Current Auction
Ends May 12th
The Einstein Archives of Ludwik Silberstein Auction Preview
Begins May 13
Advanced Search
By Item Number
Gallery Search
Past Auction Search
How Do I Bid?
What is BidTracker™?
New Bidder Registration
The 30-Minute Rule
Terms and Conditions
New to RR Auction?
About Us
Register to Bid
Jobs at RR Auction
Press Releases
Consign to RR Auction
How to Consign
2021 Auction Calendar
Jan 13
Jan 21
Feb 10
Feb 18
Mar 10
Mar 25
Apr 14
Apr 22
May 12
May 20
  View All Dates & Deadlines

Item 2105 - 1950s 4-Wire Core Memory Plane Catalog 588 (Jul 2020)

Back To Previous Page
(we are no longer accepting bids on this item)
Minimum Bid: $200.00
Sold Price: $541.25 (includes buyer's premium)


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.


Click image to enlarge Click image to enlarge

Important Information

Tips For Consignors


For a complete list of auction beginning and ending dates, check our dates and deadlines page.