Computer 1 DB9                        Computer 2  DB9
           ---------------                       ---------------


            5*--------------------------------------* GROUND
                 *9                                     *9
             *---------------------\    /-----------* DTR
                 *                  \  /                *
    TMT DATA *--------------\ /-->>  \/  <<---------* TMT DATA
                 *           x       /\                 *
    RCV DATA *--------------/ \-->> /  \ <<---------* RCV DATA
                 *-----------------/    \---------------* DSR
            1*                                     1*





            Pins 2,3 crossed between machines  (RCV-TMT)
            Pins 4,6 crossed between machines  (DTR-DSR)
            Pin 5 runs straight through        (GROUND)