The MINOS data acquisition system

The MINOS long-baseline neutrino experiment consists of two detectors separated by 730 km. Both are equipped with identical data acquisition systems, based on continuous, dead time free readout. Data are read from the untriggered front-end electronics by VME single board computers and transferred across high-speed PCI data links for consolidation by data routing processors. An array of Linux computers selects events of interest using software-based trigger algorithms. We present the design of the DAQ system and report on experience gathered during early operation of the experiment.