The invention relates to a system for interconnecting memory slot machines, for example parking meters or ticket vending machines. Each slot machine (B.sub.1, B.sub.2, . . . ) includes a circuit (C.sub.1, C.sub.2, . . . ) which receives data to be transferred. These circuits are interconnected by a seizure...http://www.google.ca/patents/US4812805?utm_source=gb-gplus-sharePatent US4812805 - System for interconnecting parking meters having a memory
