The Homogeneous Multiprocessor is a tightly-coupled, MIMD architecture consisting of a number of identical processing elements, and two types of interconnection pathways:​ (1) a distributively controlled network of switches ("extended buses") which permits each processor to access the memory of its two immediate neighbours, and (2) a fast local area network (H-Network) which permits each processor to communicate with all the other processors in a point-to-point or broadcast mode Experiments to study the behaviour of the switching network under a varying interprocessor communication demand, and to obtain a performance measure of the Homogeneous Multiprocessor by simulating distributed algorithms, are carried out on a simulator written for the Homo geneous Multiprocessor. The operating system is based on a distributed operating system nucleus — the HM-Nucleus, which has a hierarchical design that provides a distributed test,bed environment for distributed applicatión programming, in which the prominent features of the hardware structure are presented to the user in easy-to-use abstractiơns. Operating system support for distributed applications on the Homogeneous Multiprocessor architecture includes Interprocessor communication mechanisims, distributed datá structure management, and global naming mechanisms.