SIM360: A S/360 Simulator

Abstract

Modern, large-scale computer systems typically operate under the control of an operating system or executive program, and reserve for the exclusive use of the operating system a set of privileged instructions, which the normal users may not issue. This very necessary arrangement produces a problem of equipment availability for those who wish to develop or investigate operating systems programs, because such programs cannot be run as normal user jobs under an executive program. This thesis describes SIM360, a detailed simulator of the representative IBM S/360 computer, which was written to run student programs, programs assigned as machine problems for a course in operating systems. The simulator allows programs to issue all of the priveleged instructions of the S/360, and thus provides a readily available tool for the study of operating systems programs.