keyboard for 8085

Discussion in 'The Projects Forum' started by swakki, Apr 13, 2008.

  1. swakki

    Thread Starter New Member

    Apr 13, 2008
    How to connect a keyboard, printer & LEDs simultaneously to microprocessor 8085??

    I'm a second year engineering student & working on a project which is involving a use of microprocessor intel 8085 & i'm in a situation where i need to connect a keyboard to it via 8255 ppi specifications for keyboard are it should have 16 keys for entering hexadecimal so i'm not getting how to connect these many devices to microprocessor also is it possible to manage this using only one 8255?
    If not then how many of them should i use n how should i connect them?
    should i use handshake mode for it
  2. Papabravo


    Feb 24, 2006
    Hint: 16 keys is easily done as four rows of four keys. Easily done with one 8-bit port. I think the 8255 has three.