The Bellcord - A Multilevel Fast Preprocessor for 1024 ECL Channels

To provide a fast decision trigger on multiple tracks passing through multiwire proportional chambers, a high speed (arriving at an answer in 60 nsec) track counting system was developed at Fermilab. The circuit is capable of selecting the track multiplicities utilizing a coaxial cable "Bus" (the Bellcord) on which fast pulses are summed. Up to 16 Bellcord coax cables, each having 64 inputs, are fanned into a central "Hub" processor where the trigger level decision is made.