Operating System Concepts

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What is an Operating System?
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 Components
. Hardware – provides basic computing resources (CPU, memory, I/O devices).
2. Operating system – controls and coordinates the use of the hardware among the various application programs for the various users.
3. Applications programs – define the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business programs).
4. Users (people, machines, other computers).

Mainframe Systems

.Reduce setup time by batching similar jobs
.Automatic job sequencing – automatically transfers control from one job to another. First rudimentary operating system.
.Resident monitor
initial control in monitor
control transfers to job
when job completes control transfers pack to monitor