On 15 Aug 1999, Eric Smith wrote:
William Donzelli <aw288(a)osfn.org> wrote:
It seems to me that maybe, just maybe, if you
shine a bright enough image
(with very good contrast) at a stock CRT you could detect the variations
in the beam current. I think this was tried a while back in a CRT
specially made for the application in an early memory device.
I imagine you're thinking of Williams Tube memory, which was used on
various computers before core memory was available, including the IBM 701
and 702 (their first mass-produced electronic computers for scientific
and business applications, respectively).
And the Bureau of Standards Southwestern Automatic Computer (or SWAC).
The first computer built west of the Rockies, and the fastest in the world
when it was inaugurated (fall of 1950). Built at UCLA by a team headed by
Harry Huskey.
IBM apparently was never able to make Williams Tube
memory work reliably
at the density that they originally quoted to customers (1K bits per tube),
so they scaled it back to 512 bits per tube with twice as many tubes.
The SWAC's density was 1 bit per tube :)
Sellam Alternate e-mail: dastar(a)siconic.com
------------------------------------------------------------------------------
Don't rub the lamp if you don't want the genie to come out.
Coming this October 2-3: Vintage Computer Festival 3.0!
See
http://www.vintage.org/vcf for details!
[Last web site update: 05/25/99]