Operating Systems Keywords
kernel
"The one program running at all times on the computer"
Computer system can be divided into four components: (4) Users
People, machines, other computers
DRAW THE FOUR COMPONENTS OF A COMPUTER SYSTEM!
Think critically about each portion.
Everything besides the kernel is either:
(1) a system program (ships with the OS), or (2) an application program.
USER VIEW: PT 1 What Operating systems do depends on the point of view. Users want: .... But shared computers such as (mainframe) or minicomputer must keep all users happy.
(ease of use), and (good performance). They don't care about resource utilization.
USER VIEW: PT 2 Users of (workstations) have have dedicated resources, but frequently use shared resources from servers.
...Handheld computers are resource poor, optimized for usability and battery life. Embedded computers have little to no UI. Devices in automobiles.
Operating Systems
A program that acts as an intermediary between a user of a computer and the computer hardware. Operating system goals: * Execute user programs and make solving user problems easier * Make the computer system convenient to use * Use the computer hardware in an efficient manner
Computer system can be divided into four components: (2) Operating System:
Controls and coordinates use of hardware among various applications and users.
SYSTEM VIEW: PT 1 OS is a resource allocator:
Manages all the resources. Decide between conflicting requests for efficient and fair resource use.
SYSTEM VIEW: PT 2 OS is a control program:
Manages the execution of user programs to prevent errors and improper use of the computer. Especially concerned with the operation and control of I/O devices.
Computer system can be divided into four components: (1) Hardware:
Provides basic computing resources: CPU, memory, I/O devices.
Computer system can be divided into four components: (3) Application programs:
define the ways in which the system resources are used to solve the computing problems of the users: Word processor, compilers, web browsers, database systems, video games.
bootstrap program:
is loaded at power-up or reboot. Typically stored in ROM or EPROM, generally known as firmware * Initializes all aspects of system * Loads operating system kernel and starts execution