acquisition tasks and inhibit further triggering of the station. Time-to-voltage converters on the local electronics board hold the four relative times of the four counters in a detector (determined by the crossing time of the low-level discriminator) and four times corresponding to the times of arrival of pulses sent by the neighboring four detectors, if they have been alerted. Sample and hold circuits record the four charges corresponding to the integrals of the PMT signals from each counter. Alerted stations wait for 10 μsecs for a trigger acknowledge signal from the central station; if no signal is received, their data are discarded. Triggered stations place a fast current pulse (5 mA, 10 μsec duration) onto the rib trigger request coaxial cable (RG-58, 50Ω); these signals are propagated to a central trigger box via a repeater at the rib/spine junction and a spine trigger request coaxial cable (RG-8, 50Ω). The entire array is triggered when three trigger request levels are received by the central trigger box. Then, a fast signal (12V, μsec duration) is placed on the trigger acknowledge coaxial line where it is propagated back to each station via the rib-spine network. Upon receipt of a trigger acknowledge signal, alerted stations digitize their eight times and four charges through a multiplexer and a 10-bit analog-to-digital converter (ADC). The digitized data are stored in a memory buffer under the control of a microprocessor (Intel 80186). The dominant deadtime for the array is when data are digitized (approximately 0.5 msec). Periodically (typically every 30 sec), the station electronic boards receive a command over Ethernet to transmit their data to a central computer (DEC μVAX III+). Each board switches their memory buffer and continues to accumulate data; the previous recorded data are transmitted over the rib-spine network to the center where they are recorded on disk. CASA, and its associated muon array MIA, achieved excellent performance and was the state-of-the-art in air shower experiments in the ultra high energy band for a considerable period of time after its operational period in the 1990s. Only in the late 2010s have experiments such as the Tibet Air Shower Array and the High Altitude Water Cherenkov Experiment surpassed CASA-MIA in sensitivity at energies above 100 TeV. The median gamma-ray energy for a source passing near zenith was 115 TeV. The gamma-ray angular resolution varied with the size (number of particles) in the detected shower and was