Opperating Systems Capabilities Windows and menus Reality: Screen is an array of pixels(象素数组) ● Illusion1: Menus Depending on where you click, different action happens Technique: OS looks up location where mouse was clicked, executes appropriate action Illusion 2: Overlapping windows a window may cover part or all of another When a window is uncovered, its contents are redisplaved Technique: OS saves bitmap(位图) of covered windows >)Application does not need to know how to redraw the indow
HUANG Lihua, Fudan University Operating Systems Capabilities: Windows and Menus • Reality: Screen is an array of pixels（象素数组） • Illusion 1: Menus – Depending on where you click, different action happens – Technique: OS looks up location where mouse was clicked, executes appropriate action • Illusion 2: Overlapping windows – A window may cover part or all of another – When a window is uncovered, its contents are redisplayed – Technique: OS saves bitmap（位图）of covered windows » Application does not need to know how to redraw the contents of its window
CROCOMPUTEROPERATING SYSTEMS OPERATING SYSTEMFEATURES Windows 32-bit operating system, GUI, multitasking, 98&95 networking Windows 32-bit operating system not lim ited to Intel chips nT. Me Multitasking, multiprocessing, networking 20008XP, 3003ows CE Paired-down for handheld computers, wireless communication devices OS/2 32-bit Developed for IBM PS/2. Multitasking networking
HUANG Lihua, Fudan University MICROCOMPUTER OPERATING SYSTEMS 32-bit operating system, GUI, multitasking, networking 32-bit operating system not limited to Intel chips. Multitasking, multiprocessing, networking 32-bit. Developed for IBM PS/2. Multitasking, networking Paired-down for handheld computers, wireless communication devices Windows 98 & 95 Windows NT, Me & 2000 & XP, 2003 Windows CE OS/2 OPERATING SYSTEM FEATURES
MICROCOMPUTEROPERATING SYSTEMS OPERATING SYSTEM FEATURES Unix For powerful microcomputers, workstations, minicomputers. Multitasking, multi-user processing, networking. Portable to various com puter platforms Linux Free, reliable alternative to Unix, Windows. Runs on many Platforms. Open-source Mac os For Macintosh com puters Multitasking Powerful graphics, multimedia DOS For IBM(PC-DOS)and PC (MS-DOS) Program memory: 640K
HUANG Lihua, Fudan University OPERATING SYSTEM Mac OS For Macintosh computers. Multitasking. Powerful graphics, multimedia Unix For powerful microcomputers, workstations, minicomputers. Multitasking, multi-user processing, networking. Portable to various computer platforms DOS For IBM (PC-DOS) and PC (MS-DOS). Program memory: 640K Linux Free, reliable alternative to Unix, Windows. Runs on many Platforms. Open-source FEATURES MICROCOMPUTER OPERATING SYSTEMS
Selecting an Operating Sⅴstem [s our existing software compatible with the os? Does the os have a large base of compatible software? How reliable is the Os? Does it crash frequently? Is the os available for a wide variety of hardware? How quickly does it run? How easy it is to learn and use? How easy is it to install and configure? How much does it cost?
HUANG Lihua, Fudan University Selecting an Operating System • Is our existing software compatible with the OS? • Does the OS have a large base of compatible software? • How reliable is the OS? Does it crash frequently? • Is the OS available for a wide variety of hardware? • How quickly does it run? • How easy it is to learn and use? • How easy is it to install and configure? • How much does it cost?
SOFTWARE APPLICATION SOFTWARE Generalized programs that SYSTEM SOFTWARE manage the resources of the computer, including Operating System: HARDWARE scheduled computerevent .Allocates computer resources .Monitors events -Language translators: .Interpreters compIlers -Utility Programs: .Routine operations Programs written for a specific application to perform functions specified by end users -Programming Language
HUANG Lihua, Fudan University Programs written for a specific application to perform functions specified by end users. -Programming Language APPLICATION SOFTWARE Generalized programs that manage the resources of the computer, including -Operating System: •Scheduled computer event •Allocates computer resources •Monitors events -Language translators: •Interpreters •Compilers -Utility Programs: •Routine operations •Manage SYSTEM SOFTWARE SOFTWARE HARDWARE