DuoDisk pinouts 
 
       DB-25                                       DB-19
       -------------------------------------------------
       2-------------------Ground---------------------1
       4-------------------Ground---------------------2
       9,21----------------Ground---------------------3
       10,14---------------Ground---------------------4
       23-----------------[-12 volts]-----------------5
       7------------------- +5 volts------------------6
       19------------------- +12 volts----------------7
       20------------------- 12 volts-----------------8
       8------------------- ENBL B -------------------9
       12------------------- WR PROT-----------------10
       15------------------- 00 ---------------------11
       16------------------- 01 ---------------------12
       17------------------- 02 ---------------------13
       18------------------- 03 ---------------------14
       5-------------------- WR REQ ------------------15
       24------------------- +5 volts-----------------16
       11------------------- ENBL A-------------------17
       3-------------------- RD DATA------------------18
       6-------------------- WR DATA------------------19
       1,13,22,25--------------------------No connection