Important DOS  Files

Introduction to important DOS  files

·       The commands of DOS  are divided in to the internal and external commands.

• The internal commands  of DOS  are primarily used by the user to maneuver and manipulate files

• The external commands of DOS  are located in the DOS directory

• The DOS  boot loading order should be known and the functions of the boot files  should be understood.

Key Topics

·        Internal Commands ·        External Commands ·        Making a System Disk ·        Batch Files ·        List of Batch Commands ·        Example of a Batch File

·        Standard CONFIG.SYS  Commands ·        CONFIG.SYS  file ·        AUTOEXEC.BAT  File. ·        Loading Order of DOS

 

Making a Boot Disk

You can generate a boot disk  by typing the command SYS  A: or FORMAT  A:/S .

The boot disk  contains four separate files , IO.SYS , MSDOS.SYS , COMMAND.COM , DRVSPACE.BIN .

 

System disk files

The system kernel is contained in the files  IO.SYS  and MSDOS.SYS . IO.SYS connect and controls the standard system hardware such as the hard drive , keyboard , floppy, system ports such as the printer and serial ports. The file MSDOS.SYS is responsible for setting up the DOS  filling system and locating files and folders  with the current directory  structure.

 

Internal Commands

All internal commands  are contained inside the Command.com file And are immediately recognized by the DOS  operating system .

 

External Commands

 

External commands are located inside the DOS  directory  of your hard drive . These commands are each individual programs  designed to perform a particular task.

 

Batch Files

Batch files  are files designed to run a series of commands in sequence. They are generally designed automated tasks or task which require minimal human interaction like scheduling a backing up. Generating a batch file is like writing a program and requires an understanding of programming logic.

• A DOS  batch file execute a series of DOS commands in sequence.

• It can be created with the DOS  editor.

• It has the BAT  extension.

• Can be executed by typing the file name.

• Can use Ctrl+C or Ctrl+Break to halt file.

• Useful for setting up automated tasks.

Batch file Commands

 

 

Example of a batch file

This batch file will:-

–Create a backup directory

–Copy  the contents of the DOS  directory  into the backup directory.

–Creates a EXE subdirectory  in the backup directory

–Copies all of the files  in the backup directory  which have an .exe extension to the EXE subdirectory

–Shows the files  in the backup directory  in a tree listing.

 

 

Type the following batch file in the DOS  editor and save it with the file name backup.bat.

MD  BACKUP

CD  DOS

XCOPY  *.* /S/E C:\BACKUP

CD \

CD  BACKUP

MD  C:\BACKUP\EXE

COPY  *.EXE C:\BACKUP\EXE

TREE  /F

In order to run the batch file type backup.bat at the dos prompt c:\>.

 

Config.sys  file

The CONFIG.SYS  file is the hardware configuration  file of DOS

The CONFIG.SYS  file will be loaded during the boot sequence of DOS  if it exists on the root directory  c: of the drive.

We can configure our memory , drives, soundcard modem etc inside the CONFIG.SYS  file

 

CONFIG.SYS  Commands

 

 

AUTOEXEC.BAT  File

The AUTOEXEC.BAT  is a special batch file which loads during the boot sequence.

It can be used to load any of the files  and applications  of DOS  at the system boot-up .

 

Loading Order of DOS

 

If the computer does not contain a CONFG.SYS  file or an AUTOEXEC.BAT  on the root directory , the operating system  present the you with the date, the time and the operating system version.

The loading order of DOS  is as follows

–IO.SYS

–MSDOS.SYS

–CONFIG.SYS

–COMMAND.COM

–AUTOEXEC.BAT

 

Questions

1. Choose all the internal commands? (Choose all that apply)

1. CD

2. MD

3. ATTRIB

4. XCOPY

5. DIR

2. Choose all the internal commands? (Choose all that apply)

1. Dir

2. EDIT

3. MEM

4. TYPE

5. FORMAT

3. What command creates a system disk? (Choose all that apply)

1. SYS  A:

2. SYSTEM A:

3. FORMAT  A:/S

4. FORSYS A:

5. SDISK A:

4. Which of the following are system files? (Choose all that apply)

1. IO.SYS

2. DRV.BIN

3. MSDOS.SYS

4. DRVSPACE.BIN

5. COMMAND.COM

5. Which system file contains all internal commands

1. IO.SYS

2. DRV.BIN

3. MSDOS.SYS

4. DRVSPACE.BIN

5. COMMAND.COM

6. Which of the following command are batch file commands? (Choose all that apply)

1. Choice

2. Echo

3. For

4. Drivespave

5. Next

7. Which of the following command are batch file commands? (Choose all that apply)

1. Call

2. Goto

3. System

4. If

5. Rem

8. What is the true about the Config.sys  file? (Choose all that apply)

1. Contains all hardware configuration

2. Loaded during boot sequence

3. Can be used to optimize memory  configuration

4. Loads before autoexec.bat

5. Reboots the system

Answers

1.      A,B,E

2.      A,C,D

3.      A,C

4.      A,C,D,E

5.      E

6.      A,B,C

7.      A,B,D,E

8.      A,B,C,E