4 ms·
I totally love this early principle [0] for RAM by literally writing in electrons on a 2D surface and then reading them back using the electron gun. [0] https:
by nonrandomstring 2y ago
I totally love this early principle [0] for RAM by literally writing
in electrons on a 2D surface and then reading them back using the
electron gun.
[0] https://en.wikipedia.org/wiki/Williams_tube https://en.wikipedia.org/wiki/Williams_tube
- AndrewOMartin 2y agoSee also acoustic delay lines. Basically the same but instead of using phosphorous, they use mercury, or piano-wire, but never gin. Gin was proposed by some fanciful idiot [1] but never used. [1] https://en.wikipedia.org/wiki/Delay-line_memory#cite_ref-3 https://en.wikipedia.org/wiki/Delay-line_memory#cite_ref-3
- tliltocatl 2y agoFascinating that Willams tube (and Atanasoff–Berry computer's electrostatic drum) is in some way much closer to modern DRAM and flash than ferrites that were so revolutionary back then (or acoustic delay lines for that matter).
- adrian_b 2y agoJohn Vincent Atanasoff has written in 1940 a very good report about the design of the Atanasoff-Berry computer (“Computing Machine for the Solution of Large Systems of Linear Algebraic Equations”). In this report, he had analyzed which are the possible solutions for implementing a computer memory. He enumerated 5 kinds of memories: with mechanical bi-stable devices, with electro-mechanical bi-stable devices (e.g. polarized relays), with ferromagnetic materials, SRAM (with vacuum-tube flip-flops) and DRAM (with capacitors). His list covered very well the most important kinds of memories used later. The report “First Draft of a Report on the EDVAC” written by John von Neumann in 1945 added to these alternatives the memories made with delay lines (an idea presumably taken from the discussions with the ENIAC team). Moreover, the von Neumann report has also added a second variant of DRAM besides that using discrete capacitors, i.e. the DRAM made with a charge-storing image tube, like those used at that time for video cameras ("iconoscope memory"). Therefore the idea of the Williams tube has been taken directly from the von Neumann report. It is not known whether this idea has originated from von Neumann himself or whether he had got it from someone else.