Charm Trigger
MPS fast tailer
The two charm triggers in the fast trailer. The triggers physically live close to the detectors - within about 25 light-nanoseconds in this case. The wiring connects the logic components with wires that are multiples of one light nanoseond in length to ensure signals are processed at the correct time. These days all of this is done in FGPA chips. It took about two weeks to build and debug this and it required constant tuning.