No. 1 ESS ADF: Message store — a disk memory system

A high thruput, 60 megabit, fixed head per track disk memory system was designed to meet the bulk message store requirements for the No. 1 ESS ADF System. The application in this store and forward message switcher demanded that the disk store meet the stringent reliability requirements consistent with those of an electronic switching system. The article describes the system design features, a temperature-compensated read/write scheme, a synchronizing motor servo system, and automatic maintenance techniques.