The Aleph trigger supervisor

The prototype of a FASTBUS master/slave, which in the Aleph experiment is the intelligent interface between the trigger system and the readout controllers, is described. It is based on two microprogrammable sequencers, one acting as a FASTBUS master and the other equipped with a 32-bit ALU (arithmetic logic unit); its internal registers/devices are time-shared by the two sequencers. The control part of the main protocol is implemented as two finite-state machines based on the PAL technique.<
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