How do I split eproms across sockets?

Discussion in 'The Projects Forum' started by itakestuffapart, Feb 5, 2009.

  1. itakestuffapart

    Thread Starter New Member

    Feb 5, 2009
    1
    0
    Hi everyone - I hope I'm posting this in the correct area. I'm currently working on a pcb that has 4 sockets, each accepting 27C800 type eproms, and I was wondering if there's a way to "split" or distribute, 1 x 27C322 across all 4?

    My knowledge in regards to eprom addressing is pretty much experienced-based, so although I'm not clueless as to how eproms work, I am still a novice in the grand scheme of things -

    In the past, I learned how to piggyback multiple 27C*'s, using an LS139/138 to achieve a larger rom size - so I figure that surely there is a way to go the other way around?

    Soldering/wiring is not a problem, and like I said, although my knowledge is far from advanced, I do at least have a firm enough grasp of the basics to understand a reply (i think lol) - Any input would be much appreciated, thanks all =)
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Can you provide more information about the PCB?

    What do you mean by 'split' it?
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    You can do it provided the 322 fits in the footprint of an 800. Then you have to do an address line kludge to supply the two extra address bits to the 322. That might take an additional IC to do it, or you may be able to find where the "extra" address bit for the 800's becomes individual OE^'s.

    I've done it before on a motherboard. It's very ugly.
     
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