By Naresh Gupta
LBS COLLEGE, JAIPUR
INTRODUCTION TO MS-DOS
What is Operation System?
§ An operating system is a Systems Software.
§ Operating System is a control program for a Computer System that manages (or controls) the hardware resources of a computer system (Processor, Memory, Input-Output, etc) and makes a computer easy to use.
§ OS acts as an interface between the user and hardware.
§ An operating system serves three important functions – user interface, resources management, and utilities.
Example of Operating System-
Operating systems may be classified based on their characteristics.
1) MS-DOS
2) Windows
3) MAC or Macintosh
4) Unix
5) Linux
6) OS/2
7) Fedora
8) Solaris
9) BOSS
MS-DOS – Microsoft Disk Operating System
History
ü MS-DOS originally written by Tim Paterson is an American computer programmer, best known for creating 86-DOS, an operating system for the Intel-8086.
ü This first version was shipped in August 1980.
ü Microsoft, which needed an operating system for the IBM Personal Computer, hired Tim Paterson in May 1981 and bought 86-DOS 1.10 in July of the same year.
ü Microsoft kept the version number, but renamed it MS-DOS.
ü Last updated in 1994 when MS-DOS 6.22 was released.
ü Now days, MS-DOS in no longer used.
ü However, the command shell more commonly known at the Windows Command Line is still used by many users.
Features of MS-DOS
ü It is a single user and Single task Operating System i.e. it can support only one user and one program at a time.
ü CUI (Character User Interface) or CLI (Command Line Interface) based Operating System. Where all commands are entered in text form and there is no Graphical User Interface (GUI).
ü It is 16 Bits Operating System it supports (FAT16) File Allocation Table 16 bits.
Getting into Command Line Command Prompt
C:\users>_
What is System File in MS-DOS?
ü The system files are hidden files that do not show (appear) when you use the DIR command to display a directory of a system disk.
ü MS-DOS has three essential files and many command files (set of utilities.)
ü These essential files are:
IO.SYS (Input Output System)
MSDOS.SYS (Microsoft Disk Operating System)
COMMAND.COM
ü Above three files are called system files of MS-DOS.
ü IO.SYS file take care of external resources such as keyboard, floppy drive, monitor (Manage all I/O resources) etc.
ü MSDOS.SYS file manages internal resources of the PC such as memory, storage, processor etc. (Manage all Application Programs)
ü COMMAND.COM works as use-system interface i.e., it contains MS-DOS commands (Internal Commands). All internal command executed/run by Command.com.
What is BOOTING?
· Booting means the process of loading the Operating System (or system files) into computer’s memory from disk is called booting.
· So that computer starts.
· It makes computer ready to work.
· In booting process, the command interpreter (Command.com) and system files (io.sys, msdos.sys) are loaded into computer’s memory.
· There are two types of Booting:
1. Cold Booting: Start from switching on the computer. In this stage checked POST (Power On Self-Test) operation. (Check RAM size, I/O devices etc.)
2. Warm Booting:
o Warm boot is done, when required after cold boot.
o We have to perform this process when the computer hangs up.
o We can perform it by pressing the reset button or press (Ctrl+Alt+Del) keys.
DOS Function and Editing Keys:
CTRL + S – Pause screen display
CTRL + C – Break current executing command
CTRL + ALT + DEL – to reset system
INS – Allow you to insert characters within a line
DEL – Delete one character in input buffer
ESC – Cancel line currently being displayed
F1 – Displays one character from the buffer each time
F3 – Display all character in the buffer
Reserved device names in OS
ü CON , for console.
ü AUX , for auxiliary.
ü PRN , for printer.
ü LST , for lister; introduced with 86-DOS 0.74.
ü NUL , for null devices; added in 86-DOS 1.10 and PC DOS 1.0.
ü COM1, COM2 for communication port
ü LPT1, LPT2 for Parallel Port (printer)
ü Drives Names: A: for First FDD (Floppy Disk Drive)
B: for Second FDD
C: for First HDD (Hard Disk Drive)
D: for Second HDD /CD/DVD drive if exist
Wild Card Characters in MS-DOS:
ü The asterisk (*) and question mark (?) are used as wildcard characters, as they are in MS-DOS and Windows.
ü The asterisk matches any sequence of characters, whereas the question mark matches any single character.
Type of MS-DOS Commands:
Commands:
ü Instructions given to the computer to work are called commands.
ü Command is common words between computer and the user.
ü It gives the orders to the computer to work.
There are two types of MS-DOS commands
(1) Internal commands and
(2) External commands
1. Internal Commands:
Ø Internal commands are built-in the Command.com file.
Ø It can be executed from any MS-DOS prompt (C:\>_ or A:\>_ or D:\user>_).
Ø Each of the Internal commands are memory resident.
Ø As long as when computer in on, we are ready to give internal commands.
Ø Example- CD, MD, RD, CLS, DATE, TIME, COPY, etc.
2. External commands
Ø External command is an MS-DOS commands that is not included in command.com. These are DOS utilities.
Ø Come and go through the disk file.
Ø Related program file (utility file) must be available on disk.
Ø Run separate program files, they must be read from the disk before they executed.
Ø External commands are known as Disk residence commands.
Ø They are on disks as program files, any file name with an extension of .COM, .EXE, or .BAT is considered an external command (or utility).
Ø Example: Sys, Format, Chkdsk, Scandisk, Tree, More, Mem, Mode, Print, Edit, More, Tree etc.
MS-DOS Internal commands
Environment Commands
(ये कमांड्स Computer System में internally सेट पैरामीटर को दिखाते है और new पैरामीटर/environment सेट कर सकते है l) |
Directory Management Commands
(इन commands में only डायरेक्टरी का नाम ही यूज़ |
File Management Commands
(ये commands only फाइल के लिए ही वर्क करेंगे directory के लिए नहीं l)
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· DATE · TIME · PATH · PROMPT |
· CD or CHDIR · MD or MKDIR · RD or RMDIR
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· COPY CON · TYPE · COPY · REN OR RENAME · DEL or ERASE |
(ये commands mainly batch file में यूज़ किये
|
(ये commands Computer की स्क्रीन (Monitor) पर कुछ इनफार्मेशन डिस्प्ले करते है l) |
Things to remember: 1. \ (Backslash or Backward slash is used to separate two directory. 2. / (Slash or Forward slash is used to option used with command. |
· EXIT · ECHO on/off · PAUSE · VERIFY · REM · BREAK |
· DIR · CLS · VER · VOL |
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3. There are two special characters * (asterisk) and ? (Question mark) are called wild-card characters in MS-DOS and Windows OS. 4. These wild-card characters can be used with MS-DOS commands dir, copy, del, erase, ren, xcopy etc. 5. * is used to matches any sequence of characters (select files in-group. Example:
*.* refer to all files in current directory *.cpp refer to all files, which have file extension of .cpp. Lbs*.* refer to all files which have first three characters Lbs. abc*.exe refer to all files which have first three characters abc and file .extension exe
6. ? is used to matches any single character (unknown characters). Example:
a?bd.mdb refer to file which have first char a and third and fourth chars bd and file extension .mdb. Question: Display all file in (drive c:) on the monitor of following criteria: 1. File name have first two chars nk and others two chars are known 2. File extension .cpp
Answer: C:\>dir nk??*.cpp/s/p (press enter)
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What is file?
ü A file is a collection of related information that is stored (save) on secondary storage.
ü The file name divided into two parts:
· name (first name- maximum 8 characters long)
· extension, separated by a period (3 characters long).
What is Directory?
ü A directory is a location for storing files on your computer.
ü Directories are found in a hierarchical file system, such as Unix, MSDOS, OS/2 and Unix.
ü The directory contains information about the files.
What is path?
ü PATH tells DOS, which directories should be, searched for external commands after DOS searches your working directory.
ü DOS searches the paths in the order specified in the PATH command.
What is a file path name?
ü To define names required to specify a particular file in a hierarchy of directories are called the path to the file, which you specify as a path name.
ü Path names are used with commands.