CHAPER4COMPUTERSOFTWARE.ppt

CHAPER 4COMPUTER SOFTWARE;Learning Objectives;Chapter Overview; The Problem Y2K problem has resulted from the high cost of mainframe computations and data storage in the 1950s and 1960s;Case (continued…);What have we learned from this case??;Software History and Significance;Software History and Significance(continued …);System Software;System Software (continued …);System Control Program (continued …) Process management managing the program or programs running on the processor at a given time Multitasking (or multiprogramming) managing two or more tasks, programs, running on the computer system at the same time Time-sharing a number of users operate on-line with the same CPU, but each uses a different input/output terminal;System Control Program (continued …) Multithreading a form of multitasking that focuses on running multiple tasks within a single application simultaneously Multiprocessing a computer system with two or more processors that can run more than one program or thread at a given time by assigning them to different processors Virtual memory simulates more main memory than actually exists in the computer system;System Control Program (continued …) File Management and Security managing the arrangement of, and access to, files held in secondary storage Fault Tolerance the ability of a system to produce correct results and continue to operate even in the presence of faults or errors Graphical User Interface (GUI) allows users to have direct control of visible objects and actions that replace complex command syntax;System Control Program (continued …) Major Desktop Operating Systems;System Control Program (continued …) Major Departmental Sever Operating System UNIX, Windows NT Server, IBM’s OS/2 Warp Server, Novell NetWare, and IBM’s OS/400 Major Enterprise Operating Systems IBM’s MVS (Multiple Virtual Storage), IBM’s VM (Virtual Machine), IBM’s VSE (Virtual Storage Extended), and Digital Open VMS (Virtual machine System) ;System Support Programs System s