Micronet: A reconfigurable microcomputer network for distributed systems research

MICRONET is a reconfigurable network of closely cou pled microcomputers intended for general-purpose com puting. The initial system will consist of 16 Digital Equipment Corporation LSI-11 microcomputer nodes, each with its own set of peripherals. The nodes are linked via front-end computers which send packet-switched messages over shared buses which form a passive com munications network. The specially designed front ends are on interface cards which fit in LSI-11 backplanes in each node. Each front end controls three high-speed ports: two for communications on shared buses at 0.7 megabytes per second and one for direct memory access at 0.3 megabytes per second to the LSI-11. Each front end contains 4096 bytes of memory for use in queuing message packets. Each uses two microprocessors: a Signetics 8X3006 for logic control and a Zilog Z-808 for communications routines. MICRONET has been designed to be a flexible research and simulation tool for studying distributed computer hardware and software. The topology of its communi cations network can be altered simply by reconnecting cables to a bus-definition board. Software for MICRONET will include a distributed operating system, parallel programming languages, and a network version of a simulation system for modeling the brain.