The Unitech Diagnostic Systems Diverter, known more popularly as the "Patch", was a small device designed to trick a computer or networking into overlooking breaks in its system. It achieves this by emulating signals from the damaged subsystems, presenting a correctly functioning unit to the master system. The Patch consisted of a master unit and eight slave units that were placed at junctions to the damaged subsystem.
The Patch was used legitimately by Imperial technicians during emergency repairs to prevent the systems from affecting the whole system in its attempt to cope with the break. However it was also used by members of the Rebel Alliance for espionage purposes, disguising spy activity and allowing for the stealing of classified documents. Gunman, a member of Churhee's Riflemen, also used the Patch for the opposite effect: tricking a healthy system into thinking it was breached, he was able to create false alarms, douse lighting systems and stage other diversions.