Operating SystemA set of programs that perform certain functions Starting the computer Managing programs Distributing memory Coordinating the processor and
peripherals Enabling user interaction with the
computer
Starting the computerCold boot – power is turned off O/S in ROM (read-only memory) loads BIOS
(basic input/output system) into computer memory
BIOS conducts Power on self-test (POST) to check for operability
BIOS searches for O/S CMOS (complimentary metal-oxide semiconductor)
determines where to look O/S components (kernel) loaded into memory
from storage O/S takes control of computer
Managing programsSingle-tasking Run one application at a time
Multi-tasking The ability to run more than one program at a
time Foreground – program in use Background – idle program
Multi-threading Multiple parts (thread) running simultaneously
Multiprocessing Dual core processors or multiple processors
Managing MemoryAllocates memory area for each running program Keeps programs from leaking into one another
Failure results in corrupt data, programs ‘crash’, error messages
CTRL + ALT + DEL used to close corrupt program Virtual memory an extension of RAM
Data/instructions swapped between RAM and hard drive
Works with direct memory access (DMA) to control peripherals access to RAM
User InterfacePart of the O/S that lets user and computer ‘talk’ to each otherTypes of operating systems Command line
Requires user to type keywords/commands to enter data/give instructions
Graphical User Interface (GUI) Uses little graphics – icons User uses a pointing device to enter data/commands
Mouse Joystick Keyboard Other types
UNIX (command line)
Developed by AT&T in 1970s
First preemptive multitasking system
Developed concepts of file management and path names
Client/server networking system
Widely used by corporations
WINDOWS – 3.X
Includes Windows 3.0, 3.1, 3.11, and Windows for Workgroups 3.1
Not a true operating system
Uses cooperative multitasking
WINDOWS
Windows 95 True operating
system Uses preemptive
multitasking Downward
compatible with DOS
Considered a transitional system
System UtilitiesSystem utilities are programs that help the operating system manage the computer system’s resources.
Types of utilities: File management
File finders
Backup utilities
Antivirus software
File compression
Disk scanning
File defragmentation
File management
•Known as a file manager.
•Enables the user to perform various tasks with files, folders, and directories on storage devices.
•Tasks include:
Creating folders
Saving, deleting, copying, and moving files and folders
Examining the contents of files
Launching application programs
Disk Scanning - A disk scanning utility is a program that detects and fixes physical and logical problems on storage devices
File Defragmentation - A file defragmentation utility is a program that moves data on a storage device to improve performance.
Apple's 1984: The Introduction of the Macintosh in the Cultural History of Personal Computers by Ted Friedman
Revised version of a paper presented at the Society for the History of Technology Convention, Pasadena, California, October 1997.
http://www.apple-history.com/movies/1984.mov
http://www.duke.edu/~tlove/mac.htm
Slide 13