Line and trunk translation data and operating programs for No. 1 ESS are stored in a large semipermanent memory. This memory is provided by modular units known as program stores. Each program store provides 5.8 million bits of randomly accessible permanent magnet twistor memory organized into 131,072 parallel words. The information is stored in the state of small magnets affixed to aluminum cards. Each card contains 64 forty‐four‐bit words.
Each store is designed to operate over a duplicated common bus system for both normal and diagnostic operations. The stores have a cycle time of 5.5 μ sec. Such stores are an attractive and economical solution to the problem of providing large storage capacity for information which must be protected against accidental change.
To provide an efficient and routine method for updating the information content of such stores, offices are provided with card writing equipment. This includes both card handling equipment and card magnetizing equipment under system control.
The memory hierarchy of the 1A Processor consists of call/program stores, file stores, and an auxiliary data system utilizing magnetic tape. The call/program store is a 65,536‐word, 26‐bit‐per‐word memory system using a two‐wire, coincident‐current, ferrite‐core array as the memory medium, and is capable of operating with a 1.4‐μs read/write cycle time. The file store (fs) with its disk‐file memory provides the 1A Processor with a high‐performance bulk‐storage system. Each fs controller can control from one to four disk files to provide a maximum storage of 2.56 × 106 words. Two fss make up a file‐store community of 5.12 × 106 words of duplicated storage. The auxiliary data system (ads) provides a means for efficiently transferring data between the 1A Processor call‐ or program‐store memories and magnetic tape. The tape medium is used for inputting generic programs, office data, and trouble‐location information and for out putting billing, traffic, and error‐analysis data. The ads hardware consists of data unit selectors (duss) and tape frames (tfs).
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