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View Full Version : RAND SELECTRON JOHNNIAC 256 BIT MEMORY TUBE on Ebay starting @ $29,000



inotarobot
September 30th, 2016, 03:21 PM
Hi all,

saw this eBay listing for a SELECTRON JOHNNIAC 256 BIT MEMORY TUBE at starting price $29,000, with pickup only.

Thought a few here would like to see.

http://www.ebay.com/itm/252550780696?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

https://en.wikipedia.org/wiki/Selectron_tube
Following from the Wikipedia page.

Development of Selectron started in 1946 at the behest of John von Neumann of the Institute for Advanced Study,[1] who was in the midst of designing the IAS machine and was looking for a new form of high-speed memory. RCA responded with the Selectron with a capacity of 4096 bits, with a planned production of 200 by the end of the year. They found the device to be much more difficult to build than expected, and they were still not available by the middle of 1948. As development dragged on, the IAS machine was forced to switch to Williams tubes for storage, and the primary customer for Selectron disappeared.

http://i.imgur.com/Hpw9N55.jpg http://i.imgur.com/UlYAgts.jpg
http://i.imgur.com/Ojy3CfV.jpg http://i.imgur.com/gsZJC9Q.jpg

Chuck(G)
September 30th, 2016, 04:12 PM
Very cool to see one. Probably just as rare is the much later EBAM (https://www.computer.org/csdl/mags/co/1975/02/01649340.pdf). I recall seeing a rack with the things sitting in the hallway at CDC ADL in Arden Hills, MN during the mid 70s. By 1980, all mention of this device disappeared.

Al Kossow
September 30th, 2016, 04:17 PM
Hi all,

saw this eBay listing for a SELECTRON JOHNNIAC 256 BIT MEMORY TUBE at starting price $29,000, with pickup only.



There was another one on ebay years ago. Went for a few thousand dollars.

inotarobot
September 30th, 2016, 05:34 PM
There was another one on ebay years ago. Went for a few thousand dollars.

MMM one has to wonder if this is that same one ? And now original buyer is wishing to capitalize on its rarity and the passage of time that passed since he bought it ??

inotarobot
September 30th, 2016, 05:48 PM
Very cool to see one. Probably just as rare is the much later EBAM (https://www.computer.org/csdl/mags/co/1975/02/01649340.pdf). I recall seeing a rack with the things sitting in the hallway at CDC ADL in Arden Hills, MN during the mid 70s. By 1980, all mention of this device disappeared.

I took a look at that EBAM link you added. Way interesting also. Took a screen shot of the circuit diagram, block diagram and image of one. to add here

Interesting to read the specs. Especially the one of its of size, weight and life of the tube

http://i.imgur.com/crijUxI.jpg

http://i.imgur.com/FuXxip1.jpg

http://i.imgur.com/OHlAInb.jpg