Operating System - DOS.pptx

Disk operating system

1. Operating System

2. OS - Defintion It is an interface between user and computer hardware. It is a software which performs following activities like File management, Memory management, Process management , handling input & output and controlling peripheral devices.

3. Types & Examples of OS Types 1.Single user Operating system. 2.Multi user Operating system. 3.Distributed Operating system. 4.Real time Operating system. Examples -DOS, Windows, Unix, Linux, Apple MacOS , Google Android OS, Apple iOS & etc….

4. Single user OS – Only one can use this system. It have no facilities to distinguish users but it may allow multiple programs to run. Ex : DOS Multi user OS –Multiple user can use the system. It extends the basic concepts of multi tasking with facilitates that identify persons and resources. Ex –Windows OS. Distributed OS – It manages a group of different networked computers and makes them appear to be a single computer & as all computations are distributed. Real-time OS – It is an OS that guarantees to process events or data by a specific moment in time.

5. Functions of OS Booting. Memory Management. File Management. Disk Management. Process Management. Loading & execution. Device & Printing Controlling. Allocates & reallocates the space in Memory. Control overall activities of the computer.

6. DOS- Disk Operating System It is an OS that runs from a hard disk drive. It is used to manage disk & disk files. It was together introduced by Microsoft & IBM Company in 1980s. Microsoft was called this OS as MS-DOS. IBM was called this OS as PC-DOS. It is a system that resides on & can use a disk storage device such as floppy disk, hard disk & etc.. A DOS must provide a file system for organizing, reading and writing files on the storage disks. Versions of DOS – MS-DOS, PC-DOS, Apple DOS , Dr-DOS & etc…

7. Continue… CP/M(control program for micro controller) was the first most popular OS. In Dos there are 2 types of commands. i )Internal Commands – It can be executed directly. There are 25 commands. ii)External Commands – It can be executed through file name or drive name. There are 45 Commands.

8. DOS Screen

9. Internal Commands Commands Description DIR Directory Listing CD Change to other directory MD Making or creating directory RD Removes the directory REN Renaming a file or directory DATE Displays the date TIME Displays the time VER Versions of the operating system DEL Deletes a file. TYPE Displays a content of file. CLS Clears the screen. COPY Copying a file. PROMPT Changes the prompt.

10. Internal commands

11. Internal commands continue…

12. Continue…

13. External Commands Commands Description DELTREE  used to remove a directory along with its contents. CHKDSK copies the contents of one floppy from the source drive to a formatted or un-formatted floppy disk in the destination drive. SORT used to arrange the data of a file in alphabetical order (A-Z, 0-9) or reverse alphabetical order. FORMAT Clears the content of drive XCOPY used to copy files and directory trees from one disk to another disk. DISKCOPY copies the contents of one floppy from the source drive to a formatted or un-formatted floppy disk in the destination drive. EDIT used to modify or change the data of a file.

14. External commands