An asynchronous version of a binary pixel readabout circuit has been implemented in an array with 16 columns at 500 mu m pitch and 63 rows at 75 mu m pitch. This readabout chip has been bonded with solder bumps to a silicon detector with matching pixel elements. Event information in a pixel can be strobed into a local memory by a trigger signal and subsequently read out. Without a strobe the information is continuously cleared. The complete hybrid detector has been successfully tested with ionizing particles from a radioactive source. Three such devices have been put in the CERN heavy-ion experiment WA94 in the Omega spectrometer, where they recorded particle tracks from high-multiplicity /sup 32/S interactions. Preliminary data indicate a noise of approximately 60 e/sup -/ and a threshold spread of approximately 500 e/sup -/. The timing characteristics are adequate for a fixed-target experiment.<>