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  Core Memory by Bill Degnan - 06/01/2017 11:16
Core Memory rectangular enclosure
Hand-threaded rectangular core memory enclosure after cleaning and straightening wirewrap pins. Imagine you're looking at the edges of a set of cores stacked on top of each other within this enclosure. The backplane of wires you see is the "loop around" side of each core plane wire. The outside of the frame. Click image for larger view.



Core Memory rectangular enclosure
This false-color closeup shows how the pins used to hold the wirewrap in place have been bent. Note actual memory magnets are inside of the enclosure. What you see here is the "loop around" of the wiring used to hold the core magnets. Click image for larger view.



Core Memory rectangular enclosure
This image shows the dirt and dust. Image has false colors. Click image for larger view.


Core Memory picture 2
This section cleaned up nicely. Click image for larger view.


First I straightened the wirewrap pins. Next I used compressed air to clear the dust layer. Lastly I used isopropyl alcohol to clean surfaces.

What computer did this core come from? My estimate is early 60's based on the hand threading and estimated core density. Not sure yet of the manufacturer, but my guess is IBM because of the printing used on the exterior of the enclosure. There is no actual corp logo.

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  Early 1024 Rectangular Sense Core by Bill Degnan - 06/07/2017 08:16
Rectangular Matrix Pattern Early Rectangular Sense Core Memory cir. 195x side view
The rectangular sense core wiring is I believe limited to 1024 cores. Diagonal sense (with a diagonal wire axis) replaced it. Click image for larger view.


Rectangular Sense Matrix Pattern Core Memory
Not sure the date of this core, it could have been made in the early 1950's but there is no way to know yet for sure. What computer used this kind of core? The use of diagonal sense core became the standard by 1955. Maybe this was an experiemental core for some engineering purpose. Click image for larger view.


Rectangular Matrix Pattern Early Core Memory cir. 195x
Side corner view. Click image for larger view.


More info on rectangular sense vs. diagonal sense core planes:
http://ed-thelen.org/comp-hist/Byte/76jul.html

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