The development of a multiuser system with shared files is described. The system is microprocessor-based upon hardware specially designed for the application and employs several CPUs. This has resulted in a fast-response general purpose system. Whilst it was developed for use in hotels, the design contains much that is relevant to other commercial operations requiring the same type of interactive system. The author outlines the systems features and hardware configuration and describes the software in detail. The high-level language, CORAL 66, and structured programming were used effectively.