The document discusses the Disk Operating System (DOS) and provides information on operating systems, DOS commands, file management, directories, and more. It defines operating systems as programs that control computer operations by accepting input, processing it, and outputting the results. DOS is introduced as a single-user operating system that manages memory, input/output, files, and interprets commands. Common DOS commands are also summarized, including DIR to display files, COPY to copy files, DELETE to remove files, and Wildcard characters like * and ? for file searching.

1. DISK OPERATING SYSTEMDISK OPERATING SYSTEM

2. DOS SYLABUSDOS SYLABUS

3. OPERATING SYSTEMOPERATING SYSTEM
FUNCTION OF OPERATING SYSTEMFUNCTION OF OPERATING SYSTEM
TYPES OF OPERATING SYSTEM’STYPES OF OPERATING SYSTEM’S
DEFINITION OF DOSDEFINITION OF DOS
DOS COMMANDSDOS COMMANDS

4. An Operating System is the set of programs.An Operating System is the set of programs.
Which are used to control the computerWhich are used to control the computer
operation. The main function of Operatingoperation. The main function of Operating
System is to accept the data or informationSystem is to accept the data or information
through the keyboard and when the processingthrough the keyboard and when the processing
is over to transfer it to the output device.is over to transfer it to the output device.

5. Most Operating System performs the followingMost Operating System performs the following
functions:functions:
• Processor Management : It assigns different task/jobsProcessor Management : It assigns different task/jobs
that have to be performed by a computer to thethat have to be performed by a computer to the
processor.processor.
• Memory Management : It allocates memory andMemory Management : It allocates memory and
storage area to the data and user programs.storage area to the data and user programs.
• Input/Output Management : It coordinates and assignsInput/Output Management : It coordinates and assigns
different input and output devices while one or moredifferent input and output devices while one or more
programs are being executed .programs are being executed .
• File Management : It stores files on various storageFile Management : It stores files on various storage
devices and transfer these files from one storagedevices and transfer these files from one storage
device to another. It also allows the normal file editingdevice to another. It also allows the normal file editing
or other tasks.or other tasks.
• Interpreter : It Interpreter commands and instructions.Interpreter : It Interpreter commands and instructions.
• Maintenance : It maintains internal time clock and logMaintenance : It maintains internal time clock and log
of system usage.of system usage.

6. Operating System are basically 2 typesOperating System are basically 2 types
• Single user operating systemSingle user operating system : As the name: As the name
suggests that OS is single user, only a one personsuggests that OS is single user, only a one person
can work at a time.can work at a time.
EX: DOSEX: DOS
• Multi user operating systemMulti user operating system : unlike single: unlike single
programs OS, the multi-user OS supports multi-programs OS, the multi-user OS supports multi-
programming. i.e., more than one user can beprogramming. i.e., more than one user can be
supported by it. Therefore more than one usersupported by it. Therefore more than one user
programs are loaded and active in the main store atprograms are loaded and active in the main store at
the same time.the same time.
EX: WINDOWS, LINUXEX: WINDOWS, LINUX

7. As we have already discussed , an operating system is a
set of programs, that controls the operations of a
computer. It works like traffic policeman who controls
the traffic. Similarly , DOS controls the flow of
information and directs it as per the instructions given
by the user.

8. MS-DOS is one particular operating system, which
was adopted by IBM for its PCs. It was developed in
1980 using INTEL Microprocessor chip. The DOS is
stored on a disk and it must be in the RAM before
the computer is used for any work.
IO.SYS
MSDOS.SYS
COMMAND.COM
Two of these files are hidden. These are IO.SYS and
MS-DOS.SYS. the third file is not hidden. It is called
COMMAND.COM. These three files are used for
booting a computer.

9. BOOTING
To begin using your computer, you most boot the
system. In computer jargon “Booting” means getting the
machine to the accept your instructions. There is a small
program in ROM called the “Bootstrap loader “ which is
the first thing read when the power is turned on. The
bootstrap contains one simple directive –start reading
the instructions.
When the using computer is switched on, the
instructions written in ROM are executed. ROM (Read
only Memory) is the permanent memory of the
Computer. It checks RAM, Keyboard, disk drives and
other peripherals. It is called POST( Post On Self Test).
If anything is missing then an error message is shown
on the screen.

10. Dos basically operates on two types of commands.
They are internal and external commands.
Internal commands are some programs that are
resident whenever you respond to the MS-DOS prompt.
These commands are called internal because they are
inside the ROM and ready for use, whenever you are
operating MSDOS.
Ex: DIR, COPY, RENAME, DEL, ERASE, TYPE Etc.,
External commands do not make their home inside
the RAM. This means that they are not available when
you see the MSDOS prompt. These external programs
must be loaded from the operating system disk.
Ex: CHKDSK, DISKCOPY, FORMAT Etc.,

11. Some of the MSDOS commands and their function
CLS: Clears the screen displays and places the cursor
at DOS prompt in the upper-left position.
DATE: Sets the DOS system date.
Format: DATE [mm / dd / yy]
TIME: Sets the DOS system Time.
Format: TIME [ hh: mm: ss]
DIR: Displays a list of files in the specified directory
DIR/P: Directs DIR to pause each screenful of
information and displays the prompt
DIR/W: Directs DIR to displays the files in short form
(files names only), with five file names across the
screen.

12. DIR/ON: Directs DIR to displays the file in an ascending
order of file name , DIR/O-N Forms the order in
descending.
DIR/OE: Directs DIR to displays the file in an ascending
order of extension , DIR/O-E forms the order in
descending.
DIR/OS: Directs DIR to displays the file in an ascending
order of size , DIR/O-S forms the order in descending.
DIR/OD: Directs DIR to displays the file in an ascending
order of date , DIR/O-D Forms the order in descending.
EXIT: To come out dos to windows.

13. COPY CON: Copies the keyboard entries to the given
file (Command to create a file )
Format: COPY CON <file name>
Ex: COPY CON TEST
Note : CTRL+Z or F6 keys should be used to save the
new entries to the given file name.
TYPE : Displays the contents of the specified file from
the specified drive.
Format : TYPE <file name>
Ex : TYPE TEST
COPY : Copies one or more files to the specified new
destination.
Format : COPY <Source file> <Target file>
Ex : COPY TEST EXAM

14. RENAME or (REN) : Changes the name of the files
specified into first parameter to the name and extension
given in the second parameter.
Format : REN <old name> <new name>
Ex : REN TEST TEMP
EDIT : To manipulate the data in a specified file.
Format : EDIT <file name>
Ex : EDIT TEMP
DELETE / ERASE : Deletes the specified file from the
specified drive or path.
Format : DEL <file name>
Ex : DEL TEMP

15. WILD / META CHARACTERS
Wild characters are those characters, which are used for
substituting one character or a set of characters. The
wild characters are used to restrict the scope of a dos
command to only those files which matches the pattern
specified.

16. Types of Wild / Meta Characters:
They are of two types “*” & “?” where “*” can substitute a
set of characters and “?” can only substitute single
character at a particular position.
Ex. DIR S*: Display all the staring with “S” characters
regardless of the extension in the
directory.
DIR *.EXE : Displays all the files which has the
extension as EXE
DIR *.?A? : Display all the files with the extension
with “A” being second character.

17. FILES & DIRECTORIES
FILES: Files are collection of interrelated information.
DIRECTORIES: Directories are collection of sub
Directories and Files .
CREATION OF DIRCTORIES
MAKE DIRECTORY [ MD ]: To create a new Directory
FORMAT: MD <Directory Name>
Ex: MD KEONICS

18. CHANGE DIRECTORY [ CD ]: To change root Directory
to Sub Directory
FORMAT: CD <Directory Name>
Ex: CD KEONICS
REMOVE DIRECTORY [ RD ]:- To delete directory.
SYNTAX: RD <directory name>
Ex: RD KEONICS
DELTREE: To delete or remove all sub directories, files
in specified main directory.
SYNTAX: DELTREE <directory name>
Ex: DELTREE KEONICS

19. CD.. : To move from sub Directory to main Directory
Ex: C:KEONICS>CD..
CD : To change to root Directory
Ex: c:KEONICSMICRO>CD