Ch-7 Computer Software

What is Soft Ware?
Software is a set of detailed step-by-step instruction that tells to Computer what to do, how to do. Without software computer is nothing. For each task computer has a separate software, there are a number of software are used in computer i.e. Windows, MS-Office, Languages, Packages, Games etc. computer software is divided into two main categories one is System Software and other is Application software.

Types of Software:
Software can be divided into two main parts.

COMPUTER SOFTWARE




System Software Application Software

Operating System
Productivity S/W
Language Translator
Business S/W
Service Software
Education S/W

Entertainment S/W
System Software.

System software’s has designed to help the hardware components work together and provide support for application softwares. OR Which coordinate the operation of the computer and help the computer to carry out its basic tasks.

Operating System.
Operating system is a collection of system programmers that control and coordinate the overall operation of a computer system. These programmers act as an interface between the hardware and the application software. DOS, Windows & UNIX are popular operating systems. Without operating system a user cannot communicate with computer. All input & output devices run on operating system i.e. Printer, Scanner, Digital camera. Modem & Speakers etc. We cannot run application programs without operating system like Ms-Office, Games & movies etc.

Language Translator.
The Users are used high-level languages for computer programming, and we know computer understands machine language (0 & 1). As translator translate these high level languages into machine language. Each computer language has its own translator. There are three types of translators are used.

1. Compiler 2. Interpreter 3. Assembler

Service Software.
These types of software are used to look after the computer i.e. Anti virus remove virus. Scan Disk also scan the disk, and drivers provide facilities to hardware components. There are three main types of services software.

i. Utility Software
A program designed to perform maintenance work on the system or on system components (e.g., a storage backup program, disk and file recovery program, or resource editor, Anti Virus programs, screen savers, data compression etc).

ii. Library Programs
Library programs are predefining function used in languages. Usually these types of functions help in mathematics problems such as root, log, matrix, exponentiation function etc.

iii. Device Drivers

Each device of the computer work on the basis of computer software, it is called device drivers. Sound card, Scanner, Printer etc have own drivers. Without driver component cannot perform their function. As every component of computer has its own driver.


APPLICATION SOFTWARE
The software that used to perform a specific function is called Application software. Application software is used to improve our working ability. We need different type of application software to perform different tasks. There are four main types of Application software.

1. Productivity Software.
The most important software that used to solve a specific problem. There are different types of productivity software: -

• Word Processing Software. (Word Star, WordPerfect, Ms-Word etc)
• Spreadsheet Software. (Lotus, MsExcel etc.)
• Database Software. (FoxPro, dBase, Access, Oracle, Visual Basic etc.)
• Graphics Software. (Coral Draw, 3-D images, Adobe Photoshop & animations etc)
• Communication Software. (Network Software, Internet Explorer etc)
• Integrated Software. (Ms-office, which easily connect all Programs with each other)

2. Business Software.
The software that use for business purposes is called Business software. These kinds of software help to prepare Payroll, Inventory Report, Cash Book, Ledger, Profit & Loss and Balance Sheet statements etc. Banks, Industries, Stores, Farms etc are used this software for their own purposes.

3. Entertainment Software.
The software, which is used for entertainment and enjoyment purposes, is called Entertainment software i.e. games, themes, cartoons & movies etc.

4. Education Software.
The software that used for Education purposes is called Education software. These kind of software helps to student, that how to learn a topic or subject. For examples how to speak English language, how to use windows, Ms-word etc. now a days all subject software are available on CDs i.e. Computer, Physics, Chemistry, Math etc.

Operating System
An operating system is a special software program that is loaded into a computer (RAM) at startup and is responsible for running the computer. It manages all the hardware, and provides an interface between the computer's hardware and the user. Without operating system user cannot communicate with computer, because every input / output devices run on the basis of operating system.
Popular operating systems are Windows, DOS and UNIX etc. There are two types of operating system.

1. Single user Operating System 2. Multi user Operating System


1.Single user Operating System: -

Single user operating system runs on single PC. One user can use a computer at a time, and run only one program. These type of operating system does not capabilities of Networking i.e. shares resources (devices), share data etc. DOS is most popular single user operating system.

2. Multi user Operating System: -
These types of operating systems run on multi-user computers such as Mainframe & Minicomputer, and also we can use these types of operating systems on microcomputers for Networking purposes. These types of operating systems have the futures of networking and share data & resources among other computers. Some popular multi-user operating systems are Windows NT, Windows XP, Unix, LAN, WAN etc.

COMPUTER FILES
There are two types of computer files one is Data File other is Program File

Data File
A file consisting of data in form of text, numbers, or graphics etc are called data file. Usually application software is used to create these types of files.


Program File
These kinds of files have such command and instructions for execution, and used for a specific function i.e. Format file, Fdisk file, Scandisk file etc.

DOS Files
EXE. Files. These kinds of files are also called executable files. A user can run that kind of files from DOS Prompt (C:\>). Usually these files have EXE extension. Examples are comp.exe, fdisk.exe, format.exe etc.


COM Files.
COM stands for command.com, and also helps in booting process. The DOS all internal commands stored in this file. Example are command.com, diskcopy.com etc.

BAT files.
This file is a combination of different commands. That worked in process (booting) time. A user can create a batch file according to their need, i.e. autoexec.bat, that work automatically in booting time. We can display any thing during booting time on screen with help of this file.
Example:
1. 1. PATH C:\; C:\DOS; C:\UTILITY; C:\BATCH
2. PROMPT $P$G
3. SET TEMP=C:\TEMP
4. DOSKEY
5. SMARTDRV

1. Specifies the directories that DOS should search for executable files and the order in which
The directories should be searched.
2. set the appearance of the command prompt
3. this variable store temporary files
4. load the doskey program into memory
5. speed up access to hard disk

D O S
DOS stands for Disk Operating System. DOS is a single user and single tasking operating system. It is also called command-line interface operating system. In this operating system commands are used to perform a specific task. A user is used each command in written form, & press Enter key for execution. DOS is the first operating system that introduce by Microsoft in early eighty.

INTERNAL COMMANDS.
The Internal commands are inside in command.com file. Whenever computer switch on these commands are loaded into computer RAM, as all time are available for execution. Following are the most popular internal commands:-
CLS, CHDIR (CD), COPY, DATE, DEL, DIR, EXIT, REM, TIME, TYPE, VER and VOL.

External Commands.
External commands are remain stored on the disk. These type of commands will be present for execution example are BACKUP, CHKDSK, COMMAND, COMP, DELTREE, DISKCOPY, EDIT, FC, FORMAT, GRAPHICS, PRINT, PROMPT, RESTORE, SYS, TREE and XCOPY.

DOS Internal Commands

CLS
Syntax CLS
It is DOS Internal command. This command is used to clear the screen, and display the DOS prompt (C:) at the upper left corner on screen.

CD (Change Directory)
Syntax CD directory name
This is also DOS internal command, which is used to change directory

Examples:
CD APS (to open APS directory)
CD.. or CD\ (to close all open directories)
CD. (to close current directory)

COPY command
Syntax C: Copy filename.ext drive / directory
It is DOS internal command is used to copy one or more files from one location to another location. This command is also used with some extra parameters and switches.

Examples:
C: copy abc.bas A: (ABC.bas file will copy from hard disk to Floppy(A) disk)
C: copy *.* A:\xyz (copy all files from hard disk to Floppy drive(A) and in xyz directory)
C: copy *.com \abc (copy only com extension files from drive C to abc directory in C drive)
C: copy ?????.* A: (copy all those files, which have five charters to drive A)

DATE command
Syntax
This is DOS internal command, which is used to display current date on screen and also we can change or set the new date.
Example:

C:date
Current date is Wed 02-06-2003
Enter new data (mm-dd-yy)
mm for month in two digits
dd for day in two digits
yy for year in two digits

DEL command
Syntax del filename.ext
It is also DOS internal command which is used to delete (erase) one or more files from a specific location. This command is also used with some extra parameters.
Examples:
C: del abc.bas (abc.bas file will be deleted from drive C)
C: del *.* (all files from drive C will be deleted)
C: del *.exe (all exe extension files will be deleted)

DIR command
Syntax DIR
Dir is also an Internal command that used to displays files and directories on screen. DIR command is also used with different switches.

Examples.
C:dir (display all files and directories of drive C, with detailed information)
C:dir/P (display files and directories page wise)
C:dir/W (display files and directories widthwise, in 5 column & 20 rows )
C:dir/O (display files and directories in ascending order a to z)
C:dir/O-n (in descending order z to a)
C:dir/Od (display according to date and time)
C:dir/s (display all drive files and sub-directories files)

EXIT command
Syantax exit

This command is used to transfer control back to Window from DOS command line.

REM command
Syntax REM
REM command is used for remarks or comment in a program. It is also DOS internal command, and it is not executable command.
Example: REM “This is my personal file”

TIME
Syntax C:TIME
This is DOS internal command, which used to display current time on screen and also we can change or set the new time.
Examples:
C:time
Current time is 08:15:55.95a
Enter new time

COPY CON command
Syntax : C: copy con filename .extension
Example: C: copy con abc.txt

Copy con command is DOS internal command, which is used to create a text file. After writing text the Ctrl + Z shortcut key is used for saving the file.

TYPE command
Syntax: C: type filename.ext
Type is also DOS internal command, which is used to display the content of the file.
Example: C: type abc.txt (this command will display the text of the abc.txt file)




VER command
Syntax: C: ver
VER command also DOS internal command. This command is used to display the version of the DOS.

VOL command
Syntax: Vol
This is also DOS internal command, which is used to display the volume and serial no of the drive.

Example:
C:Vol
Volume in drive C: is Naeem
Volume Serial Number is 104D-19E0

DOS EXTERNAL COMMANDS

BACKUP Command
Syntax: source drive: target drive (C: backup a:)
Backup is an external command, which is used to copy files automatically from hard disk to floppy disk. Backup let’s you copy selected files, all files in a specified directory.
Examples:
Backup C:\ A: (this backup command will make a backup of all files in floppy disk(A).

Backup C:\WP\*.* A:/M (this command will make backup of directory WP to drive A since the last time Backup was used.
Backup C:\ A:/F (The F switch will format drive A automatically before backing up the files.

CHKDSK command
Syntax: chkdsk drive
It is DOS external command, which is used to displays status of the drive.
1. the total disk space 2. total spaces used in files
3. total spaces used in directories 4. total free space

COMP command
Syntax: C: comp file1 file2
It is DOS external command, which is used to combine two files with different switches.

Examples:
C: comp file1 file2/D (display the characters values in hexadecimal format.
C: comp file1 file2/N:100 (compare the first 100 lines of the specified files.

DELTREE command
Syntax: deltree directory name
DEL TREE is DOS external command that is used to delete directory and its subdirectories and all files of the subdirectories.

Examples: C: deltree xyz (xyz is a main directory)


DISKCOPY command
It is DOS external command that used to make duplicate copy of the disk.
Example:
C: diskcopy A: B:
Where A is the diskdrive that contains the source disk(the disk being copied) and B is the disk drive containing the target disk (blank disk)


EDIT command
Syntax: edit filename
It is DOS editor, which provide full screen for file editing or creating a text file. We can use this editor for writing purpose. Here we can write, save, open and print a text file easily.

Examples:
C: edit Provide full color screen for writing text
C: edit/B Provide black & white screen.
C: edit /H Display maximum number of lines.
C: edit abc.txt To open a blank file of abc.txt name, which is we can use for typing purpose.

FC command
Syntax: C: FC file1 file2

It is DOS external command that used to compare the contents of two files and display the differences between both files.

Examples:
C: FC abc.txt xyz.txt (this command will display the text of both files)

FORMAT command
Syntax: format drive name
Format is also DOS external command that is used to create tracks and sector in a disk, this procedure is also called formatting. Formatting is a procedure to ready a disk for using.

Examples:
C: format A: this command will format floppy disk.
C: format A:/S this command will format disk with system file. (make bootable floppy)
C: format A:/Q Q switch is used for quick formatting.
C: format A:/1 format only one side of the floppy disk
C: format A:/V V ask for the name of volume (not more than 11 characters)

GRAPHICS command
Syntax: C: graphics file name
This program is loaded prior to printing displayed graphics. To take effect, a graphics printer, such is Epson, Laser or inkjet etc.

Examples:
C: graphics filename /R Print out will be black on white paper.
C: graphics filename /b B is used for background color when color printer is used.
C: graphics filename /lcd Reproduces the image of an LCD display.(LCD type of monitor)

PRINT command
Syntax : Print File name /parameters
Print is DOS external command that print one or more files.
Examples:
C: Print abc.txt as the printer print the abc.txt file.

PROMPT command
Syntax: prompt characters

It is DOS external command, which used to changed the DOS default Prompt (C:>)
Examples:
C: Prompt display C> Prompt $p$g display C:\>
Prompt APS display APS Prompt $t display current time
Prompt $d display current date

RESTORE command
Syntax : restore drive1, drive2/swithes
The restore command is DOS external command, which is used to restore data from floppy to hard disk (this is opposite command of backup command)
Examples:
C: restore A: C: This command will copy all files from drive A to drive C.
C: restore A: C:\*.txt This command will copy only txt files from A to C drive.

SYS command
Syntax :sys drive
It is DOS external command is used to transfer system file to drive. The system files is used for booting purposes.

Example: C: sys A: copy system file to drive A:

TREE command
Syntax: tree drive / path
It is DOS external command, which show all directories and subdirectories in graphical display.

Examples: C: Tree display tree of drive C:
C: Tree/F display tree with files name.

XCOPY command
Syntax: xcopy c: a:\path/switches
It is used to copy selectively files from one location to disk to another. Xcopy command function similar copy command, but xcopy doest not copy hidden and system files.

Examples: xcopy A: C:/A this command will copy only archive file.
xcopy A: C:/D:17/06/2003 this command will copy only 17 date file.
xcopy A: C:/S this command will copy all subdirectoies files.
xcopy A: C:/E create subdirectories on target disk.

MD command
Syntax: MD directory name
MD is DOS internal command, which is used to create directory (folder).
Examples: C: md Zamzama create a directory on zamzama name

CD command (change directory)
Syntax: cd directory
This command is used to open a directory and close directory.
Examples
C: cd zamzama open zamzama directory
C: cd.. Closed zamzama directory
C: cd\ closed all open directories.

RD command (remove directory)
Syntax: rd directory name
This command is used to delete directory, but directory will be empty.

Example: RD ABC (this command will delete ABC folder or directory)

PATH
The address to a file. The path consists of the drive name, the location of the file in the directory
structure, and the filename. Example: C:\Mystuff\Myfile.doc.



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