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What is a 56k modem

  1. Jul 25, 2015 #1
    I always hear these referenced and am not exactly sure what they are. I googled it but came up with mixed results nothing exactly directly explain what a 56k modem was or did. Therefore, I was hoping someone on here could explain to me what is 56k and what is a modem?

  2. jcsd
  3. Jul 25, 2015 #2


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    Last edited by a moderator: Jul 27, 2015
  4. Jul 25, 2015 #3


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    Wow. I'm really not that old, but wow.

    "Modem" is sort of shorthand for "modulator/demodulator": https://en.wikipedia.org/wiki/Modem

    In the early days of computer networking, phone lines were used to transmit digital signals (data) by converting them to analog phone line signals (sounds). My understanding is that US federal law requires anything transmitted over phone lines to be audible, so 56k was the highest speed available: anything higher and you wouldn't be able to hear it because the pitch was too high.

    The devices people still use today to connect to broadband via cable or fiber optics are often still called "modems", though the name is probably not accurate anymore.

    And FYI, it is only in the past few years that dial-up modem connections have fallen to near zero:
  5. Jul 26, 2015 #4
    wow, I do feel old!

    At school we had BBC Micros( early 80s), and one had a modem that ran at 0.3K.

    It would take minutes to download a simple programme. In the early 80s, 1K, 16K, 32K 48K, 64K RAM machines were common. Some higher-end educational machines had 128 K or even 512k (the BBC master).

    You could connect to user groups (usually other schools), send messages
    and there was also, what we thought at the time, an amazing thing called PRESTEL which was a sort-of internet that allowed you to do things like buy things, check the weather, look at pictures of cats...



    You can see the telephone handet connected to a big 1.2k /s modem plugged into the BBC Micro.

    ah the nostalgia!

    Interestingly, Acorn, the Cambridge UK based maker of the BBC Micro (still based in Cambridge) morphed into ARM and is now possibly the largest manufacturer of processors in the world.
    Last edited: Jul 26, 2015
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