The development of ARCH¿a hybrid analogue-digital system of computers for industrial control

ARCH is a hybrid analogue-digital system of computers for control applications. The need for both a design philosophy, and a range of modules with which a computer control system can be built without specialized circuit, or logical knowledge is discussed. The development of this philosophy is described with the economic and engineering implications which affect it. The basic structure of the resulting system is described in some detail, together with some novel features of individual modules. In particular the ¿link¿ units which connect together the various controllers and regulators in a system to form a hierarchy of control are discussed. Some typical applications are referred to by way of example.