Hardware trigger system for Fermilab E866

E866 is the fourth experiment to be performed with the Fermilab Meson East spectrometer. Originally constructed in 1980 for E605, this spectrometer has since been used for E772 and E789. During these three experiments, the hardware trigger depended on components dating from the early 1970s. The trigger system was rebuilt for E866 to improve its reliability and increase its flexibility. The new system incorporates several new modules designed and built specifically for this experiment. Notably, a custom Track Correlator combines the features of a 16-bit memory lookup and a 12-bit prescaler into a single extremely fast CAMAC module. The new hardware trigger system and modules are described, and the system performance during E866 is discussed.