An appraisal of the Atlas supervisor

This report presents the performance of the Supervisor System used on the Atlas Computer at Manchester University, and describes some of the changes made as a result of our experience with the system. Although the machine is used jointly by I.C.T. Computing Service Division and the University Computing Service (U.C.S.), the figures presented are derived mainly from the U.C.S. use of the machine. We begin with an outline of the system and then describe its main sections in some detail. The ideas have been previously presented 1,2,3,4 but the system which has evolved is not described elsewhere. Logically the system is made up of several distinct parts which communicate through small well defined interfaces (the actual implementation is somewhat more complicated). It can be seen from Figure 1 that the path for a normal job is through the input supervisor and into the input well (which is at present magnetic tape). When the complete job has been input the input supervisor makes an entry in the job list, containing the information which the schedler uses to decide when to start the job. When the scheduler selects a job its job entry is passed on to the job assembler which organizes the loading of any magnetic tapes required by the job, and transfers the relevant compiler and input files into the main store.