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View Full Version : Info needed on USSR Soviet Ferrite Core Memory?



rorypoole
June 18th, 2013, 02:24 PM
I am planning to build a lot of core memory for my pdp8 straight project, so I got a Soviet core memory, its 36X36 so probably 1296 bits or 1k bit or 162k byte (if 8bit)
the cores are in great condition and would probably work, it has 4 wires per core? and the circuit board that comes with it has unfamiliar components on it, there is an orange rectangle that I am guessing is a capacitor (m10a 176), and a smaller red rectangle with 3 wires that I guess is a transistor (6 12.76)?

any one know any more about it? like what was its size, speed, and computer it was used in?

http://www.vintage-computer.com/vcforum/entry.php?411-Building-a-lot-Core-memory-for-a-PDP8-Straight-8
http://www.vintage-computer.com/vcforum/showthread.php?37391-Building-a-PDP-8-straight-8!&p=278565&highlight=#post278565
http://www.vintage-computer.com/vcforum/showthread.php?36202-How-do-I-wire-wrap-used-back-planes-to-build-a-pdp8-straight-8
http://www.vintage-computer.com/vcforum/showthread.php?34812-Weaving-core-memory&highlight=core+memory
http://www.vintage-computer.com/vcforum/showthread.php?36190-New-flip-chip-PCB-s&highlight=core+memory

rorypoole
June 19th, 2013, 07:03 PM
my guess was right, the 3 legged red devices are transistors
http://commons.wikimedia.org/wiki/File:Mountain_of_USSR_transistors.JPG
http://www.ebay.co.uk/itm/KT361B-BC250B-transistor-USSR-Lot-of-200-pcs-/140997491652?pt=LH_DefaultDomain_0&hash=item20d41afbc4

DaveH
June 21st, 2013, 04:21 PM
Very interesting, 4 wire per core sounds about right, x, y, sense and inhibit. Don't see any steering diodes though, the core i have seen ( and have) have LOTS of diodes to steer the x and y select currents, is there anything under the core plane ? , there doesn't seem a lot of drive / sense / control circuity , especially as its all discreet not IC.
Dave

rorypoole
June 21st, 2013, 05:44 PM
the only component on the core memory card is the core memory? there are a few glass diodes on the other board, the diodes must have been on another card that is now sadly lost, I was expecting 1 wire for both sense and inhibit! maybe that and the large size of the cores, and the fact its only 32 by 32 makes me think its an early core memory?