Abstract A new silicon strip detector has been designed for the fixed target experiment WA89 at CERN. The system of about 30 000 channels is equipped with SVX chips and read out via a double buffer into a FASTBUS memory. The detector provides a fast readout by offering zero-suppressed data extraction on the chip. The silicon counters are the largest detectors built on a monocrystal so far in order to achieve good transversal acceptance. Construction and performance during the 1993 data taking run are discussed.