This gives a sense of how much 1940s equipment it took to do something every mobile phone does today.
This is another device from the "if only we had memory" era of early computing. IBM had a digital vacuum tube multiplier before WWII, and semi-programmable electromechanical computing machines. Good memory devices were in the future. The 1940s and early 1950s saw quite a collection of strange memory devices, all big, expensive, or slow. Often all three. SIGSALY had massive synchronized phonograph turntables as key storage.
Memory took quite a while to get cheap. Core memory was still around a million dollars a megabyte in 1970. Memory didn't get cheap until the 1990s.
Solitaire Cyphers are the one that stuck with me from Cryptonomicon. iirc, there's supposed to be enough combinations in a shuffled deck of cards that every time anyone shuffles a deck, it should be a unique ordering.
Interesting that they added the code (random noise) to the data rather than multiply (XOR). I assume this was safe to do since averaging won’t recover much signal when the signal rate and code rate are the same.
Also interesting that the basement in that department store went down 200 feet. Was this to get a good foundation? The link does not say.
”Also interesting that the basement in that department store went down 200 feet. Was this to get a good foundation?”
It’s not as much as “below Selfridge’s” as “effectively in the cabinet war rooms”. https://en.wikipedia.org/wiki/Military_citadels_under_London...: ”There was a telephone room down the corridor that provided a direct line to the White House in Washington, DC, via a special scrambler in an annexe basement of Selfridges department store.”
as a record collector, the idea that top secret military phonographs filled with white noise may have once existed sure is exiting. can there possibly be any rarer record than one that required it's own destruction after use?
This gives a sense of how much 1940s equipment it took to do something every mobile phone does today.
This is another device from the "if only we had memory" era of early computing. IBM had a digital vacuum tube multiplier before WWII, and semi-programmable electromechanical computing machines. Good memory devices were in the future. The 1940s and early 1950s saw quite a collection of strange memory devices, all big, expensive, or slow. Often all three. SIGSALY had massive synchronized phonograph turntables as key storage.
Memory took quite a while to get cheap. Core memory was still around a million dollars a megabyte in 1970. Memory didn't get cheap until the 1990s.
[1] https://www.nsa.gov/about/cryptologic-heritage/historical-fi...