Abstract
At the National Bureau of Standards a flexible data handling system for use with the NBS Linac has been built. In developing this system the need for ease of modifications, ease of coding, and lexibility were carefully considered. The NBS system is designed around a building block concept. Certain of these building blocks represent the necessary interface between the specialized input-output devices and the computer while the remainder of the blocks represent specific devices such as analog-to-digital converters, scalers, and other devices to facilitate man-machine communication at both local and remote stations. The modular concept of both hardware and software development has allowed for great flexibility in the devices connected to the computer at any time and in the programs required for use with these devices. New hardware building blocks can be added to the system with no difficulty and with no change in existing programs. The general building-block approach to the NBS system together with examples of specific units will be described.