A RISC multiprocessor event trigger for the data acquisition system of the H1 experiment at HERA

In late 1991 HERA (Hadron-Elektron Ring Anlage, Hamburg, Germany) collided for the first time stored beams of electrons and protons. A description is presented of the multiple RISC processor system for online event filtering and reconstruction installed within the data acquisition system of the H1 experiment. Data are processed at a continuous average rate of approximately 6 Mbyte/s in parallel by approximately 20 R3000 VMEbus-based monoboard computers providing some 400 MIPS of computing power.<
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