The recently commissioned Hadron-Electron Ring Anage (HERA) electron-proton collider at DESY, Deutsches Elektronen Synchrotron has presented a challenging environment in coping with huge volumes of data in real-time. With bunch-crossing intervals of 96 nanoseconds, the H1 experiment can generate nearly 3 Megabytes of raw digital information from several hundred thousand electronic channels. The open VMEbus standard is exploited to provide the necessary modularity and system flexibility for embedding fast readout electronics in a multiprocessor design array. The architectural concepts of the data acquisition structure are discussed together with many of the experiences gained in implementing a large multi-crate system. (author).