1 CMOS Configuration Chip

1 Jumpers

1 Software n The intelligence of the computer n Computer programs, or instructions to perform a specific task n Determines what hardware is present n Decides how hardware is configured and utilized n Uses hardware to perform tasks

1 Three Types of Software and What They Do n Firmware (BIOS) Controls computer’s input/output functions n Operating systems (OSs) Provide instructions to hardware to perform tasks n Applications software

1 Functions of BIOS and OS

1 Firmware or BIOS n Provides basic instructions to hardware n Often serves as the interface between higher-level software and hardware

1 Software Layers n A hierarchy determines how software interfaces so that high-level software can depend on low-level software to manage the hardware for it n Applications software depends on the OS to interface with hardware Instructs hardware directly Uses BIOS to provide the instructions Uses device drivers

1 Software Layers

1 How Software Manages and Shares Information

1 Operating Systems n Different operating systems are written to support different types of hardware systems and user needs

1 Functions of Operating Systems n Manage BIOS n Manage files on secondary storage devices n Manage primary memory (RAM) n Diagnose software and hardware problems n Interface between hardware and software n Perform housekeeping procedures requested by user

1 Starting Up the Operating System n OS programs must be copied from secondary storage into RAM (memory) n CPU then reads from one memory location in RAM to another to receive and follow instructions

1 Starting Up the Operating System

1 Interfacing with the Operating System n Command-driven interface n Menu-driven interface n Icon-driven interface (graphical user interface or GUI)

1 Command-driven Interface

1 Menu-driven Interface

1 Icon-driven Interface

1 Survey of Operating Systems n Terms Multitasking Cooperative multitasking (task switching) Preemptive multitasking Environment Windows 3.x operating environment

1 Multitasking Environment

1 Windows 3.x Operating Environment

1 Comparison of Operating Systems n What kind of user interface is provided? n Can the OS support multitasking? n Can the OS easily manage large quantities of primary memory (RAM) and secondary storage? n How many and what kinds of applications are written to work with the OS? n How powerful must the hardware be to make efficient use of the OS? n How does the OS perform in a network?

1 Well-known Operating Systems n DOS (disk operating system) n DOS with Windows 3.1 and 3.11 operating environments n Windows 95 and Windows 98 n UNIX operating system n Windows NT n Windows 2000 n OS/2 n Macintosh operating system

1 Disk Operating System (DOS) n First OS used by IBM microcomputers

1 Disk Operating System (DOS)