TSPS No. 1: Stored Program Control No. 1A

New telephone services are regularly being conceived which place large demands upon existing switching facilities--demands which are increasingly difficult to satisfy with electromechanical techniques. The use of large high-speed memory and storecl-program logic permits the modernization of existing switching functions 1 and implemenation of new services more effectively and at lower cost than by electromechanical means. The stored program control (SPC) No. 1A has been developed as a general purpose stored program electronic processing system to provide a flexible control for implementing new or modernized telephone services. It is a system which is independent of application but with generalized interfaces to which hardware and software may be readily applied in the development of specific application systems. Bell System electronic switching machines must work reliably in an environment in which substantial noise and temperature variations may be encountered. System processing capacity must economically meet traffic handling needs over the projected life of the system. However, this requirement is generally met more readily with state-of-the2445