Very early computer memory - maybe off topic, but must see..

[UMMR]

Hi,
today I show you a true relic of the mainframe era, a very old (1955-56) electrostatic storage (memory) tube from my collection, the RCA 6899 "Radechon" (see: http://coldwar-4i.net/SAGE/EE0858-BC.html).
This vacuum tube is an early kind of computer memory and it has been used in vintage military applications like the SAGE system. Capacity is either 512 or 1024 bit (note: bit), stored as small electrostatically charged dots on a dielectric plate near the tube's front (at the right of my picture). Informations stored are then readed in a way roughly similar to that employed in Vidicon TV camera tubes.
I hope you'll find interesting this grandfather of today's many-gigabyte DDRs!!!
At the bottom right there is a picture of the original RCA advertising for the Radechon.
Paolo

[el_gecko]

WoW! Interesting and nice item!
Where did you find a such thing?

[Chiefish]

Very cool to see, that is most likely the largest tube i have seen so far.

[UMMR]

To el_gecko:
won months ago on Ebay, from seller ezsnyder (USA). This guy has many interesting tubes and sometimes vintage computer items listed, including some very strange item (maybe from military or research scrap).
Strangely enough no one was interested in this tube, zero bids, IMHO it's a piece of computer history.
Paolo

[chip68]

That particular specimen was actually made in the mid-'60s (or later), judging by the RCA logo. Generically, it's called a Williams tube:

http://en.wikipedia.org/wiki/Williams_tube

- CMW

[thomsonicus]

great stuff! a lot bigger than i thought it was (good idea with the pencil). was it before core memory or after?

[debs3759]

Very nice! That would make a great addition to any collection of memory

[chip68]

[JAC]

Nice.. now check out this bad boy....

This was sold at a live ebay auction a few months ago...

"... This electron tube developed at RCA Laboratories in Princeton, New Jersey, could store 4096-bits in one glass envelope. The Selectron was designed at the behest of John von Neumann of the Institute for Advanced Study and intended for use in their digital computer being designed during the 1940s. "



Here is more info on it...
http://home.att.net/~thercaselectron/index.html

Check out the 9 bit tubes!

[UMMR]

[monoxrom]

not in tubes, but this is ram too:

[UMMR]