Racal MA-4204 Time Division Voice Scrambler


Another device using random acoustic noise for cryptographic purposes. This device from the early 1970s randomly rearranges the audio signal every half-second; a corresponding unit puts the audio back in the correct order on the other end. While not very secure (the three 8-position switches only provide 512 possible combinations), this device’s operation and style have a nice mix of of functionality and poetics.

Via Cryptography Museum.

Notes on “Computer Lib/Dream Machines”


Some random notes from Ted Nelson’s 1974 book Computer Lib/Dream Machines:

  • “Computing has always been personal. By this I mean that if you weren’t intensely involved in it, sometimes with every fiber in your mind twitch, you weren’t doing computers, you were just a user.” (Computer Lib, page 3)
  • “People talk about the “depersonalization” of computers. I want to emphasize the personalization of computers – that they, their programs, and languages, are designed by individuals, each with his or her own obsessions.” (Computer Lib, page 4)
  • Mentions Ken Knowlton’s On the Frustrations of Collaborating with Artists – A Programmer’s Reflections (Computer Lib, page 399)
  • “When you first sit at a computer terminal, the feeling is one of sheer terror. Sweat and chills, jumpiness and sudden clumsy nervous motions, lunatic absentmindedness, and stammering fear and awkwardness interfere with your ability to function or understand the person who is helping you. It’s perfectly normal.” (Dream Machines, page 11)
  • “The computer display will be mankind’s new home.” (Dream Machines, page 13)

Ordering Pizza By Computer (1974)

“This high-tech sociolinguistic experiment was conducted at the Lab on the evening of December 4, 1974. Donald Sherman, who has Moebius Syndrome and had never ordered a pizza over the phone before, used a system designed by John Eulenberg and J. J. Jackson incorporating a Votrax voice synthesizer…” While the original order was placed with Dominoes (who hung up), the final order was successful and 30-45 minutes later the lab received a 16″ pizza with pepperoni, mushrooms, ham, and sausage.

Via: Slice