Substituting for "recirculating shift register"

Discussion in 'General Electronics Chat' started by bob800, Oct 5, 2012.

  1. bob800

    Thread Starter Active Member

    Dec 10, 2011
    I'm trying to find a substitute IC for the ancient "2524", 512-bit recirculating shift register (for use in a TV typewriter circuit). The datasheet can be found/downloaded here.

    After some researching, it appears that this is simply an enormous "ring counter", but with only the last D flip-flop available for output (?). I've searched Digikey, Mouser, Jameco, using the search term of "ring counter" among many other types, but I can't find anything like the 2524! Is there another name for this that I'm missing? (I've tried "recirculating shift register", of course).

    I would really appreciate if anyone could point me in the right direction!


  2. crutschow


    Mar 14, 2008
    The longest I know of is the CD4517 dual 64-bit shift-register. You would need four of them connected in series to give you 512 bits. That would not be difficult to do.
  3. MMcLaren

    Distinguished Member

    Feb 14, 2010
    Do you have a link to the circuit you're trying to build, please? I'd love to see what it looks like. Thanks...
  4. bob800

    Thread Starter Active Member

    Dec 10, 2011
    Thanks! It looks like that's my best option...

    Here's the magazine article I was referencing (see the schematic on the 14th page):

    And if you're interested, the full "TV Typewriter Cookbook" by Don Lancaster: