1. Chapter-3Chapter-3
Software Concepts

2. COMPUTER’S KEY INGREDIENTSCOMPUTER’S KEY INGREDIENTS

3. BASIC COMPUTER PARTSBASIC COMPUTER PARTS

4. COMPUTER’S KEY INGREDIENTSCOMPUTER’S KEY INGREDIENTS
SOFTWARE- Set of programs. Can be
stored in storage devices eg. Photoshop
etc.
HARDWARE- physical components
eg. monitor, mouse, motherboard etc.
FIRMWARE-software that are
permanently stored in an electronic
device eg. ROM
LIVEWARE- people who use the
computer eg. users, programmers, coders

5. SOFTWARE-A BRIEF HISTORYSOFTWARE-A BRIEF HISTORY

6. SOFTWARE-A BRIEF HISTORYSOFTWARE-A BRIEF HISTORY
LOW LEVEL LANGUAGES (LLL’s)
Machine language
◦ Made up of 0s and 1s (binary code)
◦ Difficult to understand
◦ Difficult to code
◦ Deals with absolute memory addresses
Assembly language (early 1950’s)
◦ Uses mnemonic/symbolic codes
◦ Uses assembler for conversion to binary code
◦ Machine dependent(1:1 correspondence b/w
assembly & machine instructions)
◦ Deals with symbolic memory addresses

7. HIGH LEVEL LANGUAGES(HLL’s)
o Similar to english
o Easy to code
o Machine independent
o Translator program-compiler used for
conversion to binary code
o Eg. COBOL, FORTRAN, PASCAL
SOFTWARE-A BRIEF HISTORYSOFTWARE-A BRIEF HISTORY

8. COMPUTER ARCHITECTURECOMPUTER ARCHITECTURE

9. TYPES OF SOFTWARETYPES OF SOFTWARE

10. SYSTEM SOFTWARESYSTEM SOFTWARE

11. APPLICATION SOFTWAREAPPLICATION SOFTWARE

12. UTILITY SOFTWAREUTILITY SOFTWARE

13. OTHER SYSTEM SOFTWAREOTHER SYSTEM SOFTWARE
ASSEMBLER
◦ Assembler converts assembly language into
binary language

14. ASSEMBLY LANGUAGEASSEMBLY LANGUAGE
◦ An assembly language program contains a
symbolic operation code and a symbolic
address:
OP-CODE OPERAND
LOAD A (load A into the accumulator)
SUB L (subtract L from the accumulator)
STORE B (store the contents of accumulator to B)
◦ It uses symbolic memory addresses
◦ It is machine dependent-does not run on
different machines.

15. OTHER SYSTEM SOFTWAREOTHER SYSTEM SOFTWARE
COMPILER
◦ Compiler converts high level language into
binary language
◦ Converts source code(written in HLL) to
object code(computer’s language)
◦ Checks the whole code at once, not line wise
◦ Eg. Turbo C++ compiler

16. TRANSLATION PROCESSTRANSLATION PROCESS

17. POINTS TO REMEMBERPOINTS TO REMEMBER
Linker links the object code to create
machine executable program
Source program and executable program
are same
Source program doesn’t run in a
computer but the translated executable
program runs

18. OTHER SYSTEM SOFTWAREOTHER SYSTEM SOFTWARE
INTERPRETER
◦ Provides program execution
environment
◦ Interpreter interprets the
source code and executes it.
◦ Interprets the code line wise
◦ Examined code is decoded
◦ Executed through equivalent
sequence of machine code
◦ Eg. GW Basic interpreter

19. COMPILER VS INTERPRETERCOMPILER VS INTERPRETER
COMPILER OPERATION INTERPRETER OPERATION

20. OTHER SYSTEM SOFTWAREOTHER SYSTEM SOFTWARE
LOADERS & LINKERS
◦ System software that combines different program
modules or functions into machine language program
is LINKER
◦ System software that moves the executable code
from magnetic storage to the main memory is
LOADER
Loader
LINKER OPERATION

21. UTILITY SOFTWAREUTILITY SOFTWARE
ANTI VIRUS
◦ Identifies and removes the virus

22. HOW VIRUS WORKS??? LET’SHOW VIRUS WORKS??? LET’S
TAKE A LOOK…TAKE A LOOK…

23. BOOT SECTOR VIRUSBOOT SECTOR VIRUS

24. BOOT SECTOR VIRUSBOOT SECTOR VIRUS
◦ Displaces boot record and copies itself on the
boot sector
◦ Cannot be overwritten by any other program
◦ During booting the copy of virus is loaded in
the main memory
◦ Virus passes control to the boot record, thus
infecting the OS
◦ Any new disk inserted also gets infected in
the same way and it goes on…

25. WORKING OF ANTI VIRUSWORKING OF ANTI VIRUS
◦ Reads boot sector and refers to its virus
directory
◦ Virus is detected if during search, any
definition matches its directory
◦ Overwrites the correct boot record over the
infected one
◦ Marks bad sector as clean
◦ Keeps an eye on all activities
◦ Scans any peripheral attached

26. FILE VIRUSFILE VIRUS
◦ Attacks executable files
◦ Every executable file has a data part and an
instruction part
X X X X
◦ The first instruction makes the control jump
on the specified address ie address of the
start of instruction part of the program
◦ Data part of the exe file is not entered into

27. FILE VIRUSFILE VIRUS
◦ File virus attaches itself at the end of the exe file eg at
address YYYY
◦ Modifies jump instruction from XXXX to YYYY
◦ YYYY is the address of virus, where control will jump
◦ Now virus will be activated in main memory
◦ The last statement of virus JUMP XXXX will be
inserted and program starts executing
X X X X
Y Y Y Y

28. WORKING OF ANTI VIRUSWORKING OF ANTI VIRUS
◦ Reads the first instruction ie jump YYYY and
refers to its virus directory
◦ If virus is detected then it does one of the
following:-
 Repairs the file-removes virus code after address
YYYY
 Isolates the file –no one can access it
 Deletes the file

29. WORKING OF ANTI VIRUSWORKING OF ANTI VIRUS
o Finally it takes the actual address XXXX of the
start of the executable program
o First statement jumps to address XXXX
X X X X
Y Y Y Y
1
3
2
Infected file Virus code removed and first statement modified

30. OTHER IMPORTANT VIRUSES…OTHER IMPORTANT VIRUSES…

31. OTHER IMPORTANT VIRUSES…OTHER IMPORTANT VIRUSES…
MACRO VIRUS
◦ MS-Office and Open Office deals with macros
◦ Macros help automating tasks
◦ Macro virus infects the normal.dot file of MS-
Word. This file stores the default settings
such as font, font size, file content etc.
◦ Damages the formatting
◦ Doesn’t allow editing of the document
◦ Sometimes doesn’t allow saving the file

32. OTHER IMPORTANT VIRUSES…OTHER IMPORTANT VIRUSES…
E-MAIL VIRUS
◦ Infects the e-mail system by attaching itself as
a message
◦ Picks up addresses and sends fabricated
messages
◦ This way it keeps replicating

33. OTHER IMPORTANT VIRUSES…OTHER IMPORTANT VIRUSES…
TROJAN HORSE
◦ Got its name from the famous story of
Greeks attacking the city of Troy
◦ Generally comes along with games
◦ When the games is run, it becomes activated

34. OTHER IMPORTANT VIRUSES…OTHER IMPORTANT VIRUSES…
WORM
◦ Keeps on replicating itself on the network
◦ Looks for security holes on the machines
attached to the network

35. WORKING OF ANTI VIRUSWORKING OF ANTI VIRUS
◦ Acts like a security guard and checks for any
suspicious activity
◦ Flags the suspicious program
◦ Scans the computer
◦ Identifies and repairs the infected files

36. DISK MANAGEMENT TOOLSDISK MANAGEMENT TOOLS

37. DISK MANAGEMENT TOOLSDISK MANAGEMENT TOOLS
DISK DEFRAGMENTER
◦ Due to lack of continuous memory space on
the disk, files are stored in fragments
◦ Some fragments get spilled over to other
cylinders
◦ File access becomes slow-as movement of
cylinder head from one cylinder to another is
a slow task
◦ Disk defragmenter brings all the fragments
together

38. DISK DEFRAGMENTATION…..DISK DEFRAGMENTATION…..

39. DISK MANAGEMENT TOOLSDISK MANAGEMENT TOOLS
DISK CLEANER
◦ Checks for the inactive files on the disk
◦ Prompts the user if these files have occupied
large space
◦ User may delete or take back up of these files

40. DISK CLEANER…..DISK CLEANER…..

41. DISK MANAGEMENT TOOLSDISK MANAGEMENT TOOLS
BACKUP
◦ Copies the important data from hard disk /
CD / any storage device
◦ Stores it on another disk- called backup disk
◦ In case of system disk failure/accidental loss,
backup file can be restored using backup
facility

42. BACKUP PROCESS…..BACKUP PROCESS…..
BACKUP SOFTWARE FOR OUTLOOK

43. FILE MANAGEMENT TOOLSFILE MANAGEMENT TOOLS
o SOME TOOLS AT GLANCE…..
◦ Windows explorer
◦ Google desktop
◦ VCOM power disk pro
◦ Free commander

44. FILE MANAGEMENT TOOLSFILE MANAGEMENT TOOLS
o FUNCTIONS PERFORMED BY THESE
TOOLS…..
◦ Storage
◦ Indexing
◦ Searching
◦ Sorting

45. APPLICATION SOFTWAREAPPLICATION SOFTWARE
WORD PROCESSOR
◦ Documentation software to create
presentable documents
◦ WYSIWYG type- What you see is what you
get
◦ Features like auto error correction, spell
check, grammar check etc.

46. WORD PROCESSOR VENDOR
WINDOWS BASED
• MS-WORD XP
• MS WORD 2007
• WORD PERFECT
• AMI PRO
• OPEN OFFICE-WRITER
MICROSOFT
MICROSOFT
WORD PERFECT CORP.
LOTUS DEVELOPMENT
SUN MICROSYSTEMS
LINUX / UNIX BASED
• Vi EDITOR PART OF THE OPERATING
SYSTEM
APPLE MACINTOSH BASED
• MAC WRITE
• WORD
• WRITE NOW
• WORD PERFECT
• OPEN OFFICE- WRITER
CLARIS SOFTWARE
MICROSOFT
T/MAKER
WORD PERFECT CORP
SUN MICROSYSTEMS

47. SCREEN SHOT- WORD 2007SCREEN SHOT- WORD 2007

48. SCREEN SHOT- OPENOFFICESCREEN SHOT- OPENOFFICE
WRITERWRITER

49. APPLICATION SOFTWAREAPPLICATION SOFTWARE
SPREADSHEET PACKAGE
◦ Also known as ESS (Electronic Spreadsheet
Software) program
◦ Matrix sheet made up of rows and columns
◦ Intersection of a row and column is a cell
◦ Each cell is identified by its cell address
◦ Visi Calc was the first spreadsheet package
followed by Lotus 1-2-3, MS Excel

50. SPREADSHEET MANUFACTURER COMPATIBLE
PLATFORM
1-2-3 LOTUS DEVELOPMENT • Apple Macintosh
• IBM microcomputers
EXCEL MICROSOFT • Apple Macintosh
• IBM microcomputers
IMPROV LOTUS DEVELOPMENT • IBM-compatible
QUATTRO PRO BORLAND • IBM-compatible

51. SCREEN SHOT- EXCEL 2007SCREEN SHOT- EXCEL 2007

52. SCREEN SHOT- OPENOFFICESCREEN SHOT- OPENOFFICE
CALCCALC

53. APPLICATION SOFTWAREAPPLICATION SOFTWARE
BUSINESS SOFTWARE
◦ Used in commercial organizations
◦ Some popular business software are:
 Inventory management system
 Payroll system
 Financial accounting