WELCOME

OPICS :- BOOTING and THE EXTERNA

COMMAND OF DOS

BY- PARAS
 BOOTING
So what is booting :-
The booting is the process of starting a computer as initiated through
hardware such as a button or by a software command. After it is
switched on , a computer’s central processing unit(CPU) has no
software In its main memory, but some process must load software into
memory before it can be executed. This may be done by hardware or
firmware in the CPU, or by a separate processor in the computer
system.
:-
 TYPES OF BOOTING

There are two types of booting :-

1. Cold booting .
2. Hot/warm booting.
 COLD BOOTING

A cold boot is also called the hard boot. It is the process when we first
start the computer. Or in the other words when the computer is started
from its initial state by pressing the power button it is called the cold
boot.
The instruction are read from the ROM (read only memory) and the
operating system is loaded in the main memory also known as the
RAM(random access memory).
 HOT/WARM BOOTING

Warm boot is also called soft boot. It refer to when we restart the computer.
Here, the computer does not start form initial state. When the system gets
stuck , lag or hang sometimes it is required to restart it while it is ON.
Therefore, in this condition the warm boot takes place. Restart button or the
shortcut key (CTRL+ALT+DELETE) are used for warm or hot boot.
 BOOTING PROCESS OF MS. DOS

In the case of DOS, booting process starts when we start computer and continues till DOS prompt
is displayed. The booting process of DOS mainly deals with loading three main system files of
DOS into memory. These files are IO.SYS, MSDOS.SYS and COMMAND.COM.
In the booting process of DOS, the following steps are performed when we start a computer –
1. Once the computer system is turned on, BIOS (Basic Input /Output System) performs a series
of activities or functionality test on programs stored in ROM, called on Power-on Self Test
(POST) that checks to see whether peripherals in system are in perfect order or not.
2. After the BIOS is done with pre-boot activities or functionality test, it read bootable sequence
from CMOS (Common Metal Oxide Semiconductor) and looks for master boot record in first
physical sector of the bootable disk as per boot device sequence specified in CMOS. For
example, if the boot device sequence is –Floppy Disk Hard Disk CDROM
3. After this, master boot record will be searched first in a floppy disk drive. If not found,
then hard disk drive will be searched for master boot record. But if the master boot record
is not even present on hard disk, then CDROM drive will be searched. If the system is not
able to read master boot record from any of these sources, ROM displays the message “No
Boot device found” and system is halted. On finding master boot record from a particular
bootable disk drive, operating system loader, also called Bootstrap loader is loaded from
boot sector of that bootable drive· into memory. A bootstrap loader is a special program
that is present in boot sector of bootable drive
4. Bootstrap loader first loads the IO.SYS file. After this, MSDOS.SYS file is loaded which is
core file of DOS operating system.

5. After this, MSDOS.SYS file searches to find Command Interpreter in CONFIG.SYS file and when it
finds, it loads into memory. If no Command Interpreter specified in the CONFIG.SYS file, the
COMMAND.COM file is loaded as default Command Interpreter of DOS operating system.

6. The last file is to be loaded and executed is the AUTOEXEC.BAT file that contains a sequence of DOS
commands. After this, the prompt is displayed, and we can see drive letter of bootable drive
displayed on the computer system, which indicates that operating system has been successfully on the
system from that drive.
COMMAND PROMPT :-
In windows operating system, the command prompt is a program that emulates the
input field in a text-based or (CUI) user interface screen with the windows
Graphical User Interface(GUI). It can be used to execute entered command and

perform advanced administrative function.

 THE EXTERNAL COMMANDS OF DOS
1. COMMAND :- EDIT
This command is allow a user to create a new file or modify the contents of
an existing file.
Syntax :- EDIT [filename.extention]
e.g:- c:\>EDIT PC.TXT

2. COMMAND :- DOSKEY
This command allows a user to keep a history of commands used on the
computer.
Syntax :- DOSKEY
e.g:- c:\>DOSKEY
3. Command :- ATTRIB
This command allows a user to change the properties or attributes of a specific
files.
Syntax :- ATTRIB [[Drive:] [path] filename]
e.g:- c:\>ATTRIB

4. Command :- CHKDSK
This command checks the computers hard disk drives’ status for any cross-linked
or any additional error with the hard disk drive, but it cannot repair the problem
found.
Syntax :- CHKDSK [DRIVE NAME]
e.g:- c:\> CHKDSK
5. Command :- FDISK
This command allows the user to delete and/or create partition on the hard disk
drive. The number and size of partition depends upon the choice of the user and
capacity of the disk.
Syntax :- FDISK
e.g:- A:\> FDISK

6. Command :- FORMAT
The newly created disk partition are generally unformatted and cannot be directly
used to store data. These disks have to be formatted with FORMAT command of
MS-DOS.
Syntax :- FORMAT [DRIVE NAME]/SWITCHES
e.g:- c:\FORMAT D:/Q
7. Command :- DISKCOPY
This command allows a user to copy the complete contents of disk into another
disk. It first formats the target disk and then copies the files by collecting files from
the source disk and copy to the target disk.
Syntax :- DISKCOPY [SOURCE PATH] [TARGET PATH]
e.g:- c:\> DISKCOPY A: B:

8. Command :- DISKCOMP
This command is used to compare two disks to find out whether they are identical
or not. If disks are identical, then ‘OK’ message is displayed else an error is
reported.
Syntax :- DISKCOMP [SOURCE PATH] [TARGET PATH]
e.g:- c:\> DISKCOMP A: B:
9. Command :- FIND
This command allows you to search for text within a file. Although MS-DOS itself is
not case-sensitive, when typing in the string that you are looking for with the find
command, it is case-sensitive. Additionally, this command is used to find text within
a file, not the actual file itself.
Syntax :- FIND ‘STIRNG’ [[DRIVE:] [PATH] Filename
e.g:- c:\>FIND ‘REM’ AUTOEXE.BAT

10. Command :- MORE

This command allows information/contents of a file to be displayed one page at a
time.
Syntax :- MORE [Drive:][Path][Filename]
e.g:- c:\> MORE PARAS.TXT
11. Command :- SORT
This command sorts the input and displays the output on the screen. This command
can be used with other command by using pipe symbol in many combination.
Syntax :- SORT [DRIVE][PATH]FILE NAME]
e.g:- c:\>SORT D:\PCS\P1.TXT

12. Command :- TREE

This command displays the list of files and sub-directories of a given directory in a
tree like structure.
Syntax :- TREE [PATH]
e.g:- c:\> TREE
13. Command :- DELTREE
This command deletes all the files and sub-directories of a given directory
completely. It prompts to verify the deletion which can be removed by using the
switch ‘Y’.
Syntax :- DELTREE [/Y][DRIVE:][PATH]
e.g:- c:\>DELTREE/Y

14. Command :- XCOPY

This command is a powerful version of the COPY command with additional
features. XCOPY has the capability of moving files, directories, and even whole
drives from one location to another.
Syntax :- XCOPY [SOURCE PATH][DESTINATION PATH]
e.g:- c:\> XCOPY C:\TEMP/E
15. Command :- SYS
SYS command is used to copy the system files from one drive to another drive,
allowing that target drive to be bootable. When running the SYS command, the
following files will be copied: COMMAND.COM, IO.SYS, MSDOS.SYS, DOS.COM,
BIO.COM.
Syntax :- SYS [DRIVE NAME]
e.g:- c:\>SYS A:

16. Command :- SCANDISK

This command is used to check and repair various kinds of disk error. It thoroughly
checks the disk and reports any kind of bad sectors (in found). This is an extension
of CHKDSK command.
Syntax :- SCANDISK [drive name]
17. Command :- BACKUP
This command enables users to backup their data on their computer.
Syntax :- BACKUP [SOURCE PATH][TARGET PATH]
e.g:- c:\>BACKUP C:\WORK\*.* D:/S

18. Command :- RESTORE

This command is used to restore files copied by BACKUP command.
Syntax :- RESTORE [SOURCE PATH][TARGET PATH]
e.g:- c:\>RESTORE A: D: \PCS/S
19. Command :- MODE
This command perform various functions relating to the transfer of data between
the processor, screen, printer and the keyboard.
Syntax :- MODE [DEVICE]
e.g:- c:\>MODE CON

20. Command :- MOVE

This command allows you to move files from one directory to another or from one
drive to another.
Syntax :- MOVE [SOURCE PATH][DESTINATION PATH]
e.g:- c:\>MOVE C:\P2.DOC E: \P2.DOC
21. Command:- UNDELETE
This command allows the user to restore files that may have been deleted.
Syntax :- UNDELETE [DRIVE:][PATH][FILE]
e.g:- D:\>UNDLELTE C:\WINDOWS\SYSTEM\ *.*/all

22. Command:- PRINT

This command is basically used for printing the files. This command is used to set
aside some space in RAM for printing the file in the background while user
continues working in DOS.
Syntax :- PRINT [FILE NAME]
e.g:- C:\>PRINT PARAS.DXT