Because the KC-192 computer is certified in 40 different aircraft types, adapter modules are used to provide specific software algorithms to the particular adjustments needed for proper performance in all modes for each specific airframe. There are 2 modules for each KC-192 flight computer encased in resin to prevent altering. The modules are installed into 40 pin sockets located on the inside of the top cover and the top board in the unit. Please see diagram below.