A Prototype Crate and Module System for a High Speed Top-Mounted Bus

A prototype crate and module system, which uses the top surface of the modules both for mechanical support and for electrical connection to data and power buses, has been built to evaluate its potential use in a fast ECL bus environment. Although the system was optimized for a wide, fast bus using transmission lines and emitter-coupled-logic buffers, the construction has advantages and economies which may make it useful in low performance systems as well. Both the front and rear module ends are available for user controls and connections. The vertical size of the modules is independent of the bus mechanics. Modules can be inserted and removed from either the front or the rear of the rack. Construction details of the prototype are given.