Management of Computer : Management of Computer Equipments of computer & people working on computer can be classified as under:
Hardware
Software
Firmware
Human ware
Slide 2 : Hardware: Computer's internal/external equipments which can be seen & touched e.g. keyboard, VDU, CPU, Mouse, CDD, FDD, Joystick, Printer & Modem etc are called hardware.
Software: To operate a computer some programs are required which tells computer what to do & how to do. These programs are written in computer languages A set of such programs is called software, which can be seen but cannot be touched. e.g. Visual Basic, D-Base-III-IV-V, Lotus-I-II-III, CAD, Tele text, Pascal, C, C++ and Operating Systems etc.
Program: To perform a particular task a set of instructions written in sequence is called program.
Slide 3 : Firmware: Some software which are permanently burnt in ROM by the manufacturer are called firmware. These software are necessary for the internal/initial functioning of the computer.
Humanware: The personnel which are related to installation, maintenance, operation & testing of computers are called human ware. For example: Programmers, Data Typists, Hardware/Networking Engineers & System Analysts.
Software : Software To operate a computer some programs are required which tells computer what to do & how to do. To perform a particular task a set of instructions written in sequence is called program. A person who writes these programs is called Programmer. These programs are written in computer languages. A set of programs is called software.
Types of Software:
System Software.
Application Software.
Slide 5 : System Software: It includes programs those are necessary to operate and control a computer system.
e.g. Operating System, Boot Program and other computer maintenance software.
Application Software: The programs or Software that are used to perform specific tasks. Computer languages are used to make this types of software. These are also called general purpose software. Some general purpose software are:
Word processing software: Word Star, MS Word, Word Perfect.
Data Analysis (Spread Sheet) : Lotus-1-2-3, SCO Professional, MS Excel.
Data Management Software: D Base-4, Fox Pro, Fox Plus, MS Access, DB-2, Oracle, Lotus Approach, SQL Server.
Desktop Publishing Software: Ventura, Page Maker, Corel Draw, Press works etc.
Graphics Tool: Adobe Photo Shop, Paint Shop Pro.
Presentation: Microsoft Power Point, Presentation Graphics.
Web Browser: Internet Explorer, Mozilla, Netscape Navigator.
Software Piracy: Software are created by Engineers by hard work and lot of time. So software are costly but people make copy of software
illegally. Which is called software piracy which is punishable.
Operating System : Operating System Diagram: End User Application Software Operating System Computer Hardware
Slide 7 : Operating System is a system software that allows easy interaction of the user with the hardware. It hides complexity of hardware from user. It provides many services.
Acts as a user/computer interface.
Acts as resource manager.
Access Input/Output devices.
Detects errors.
Protects the CS.
Types of Operating System : Types of Operating System Single user operating system: By using SUOS only one user can work on the system at one time. It also called stand alone system. MS DOS is a popular operating system for single user machine.
Multi User Operating System: By using this system many user can work on the system at one time. Many computer can be connected with each other & the resources of the computer system can be used by more than one user. System is capable of executing one or more tasks at a time e.g. UNIX & Window NT.
Slide 9 : Operating system may also be classified as:
Character Based Operating System: All commands/instructions has to be typed. For example - DOS.
Graphical User Interface O.S. : All the commands/programs are in the pictorial (icons) form. Commands/Programs can be execute with the help of mouse. One has to point on the icon and click the mouse to open the program. For example – Windows NT, Windows XP, Windows 98, Windows 2000, Windows Vista, Open server UNIX OS, OS/2, Novell Operating System version 4.1.
Booting : Booting When you switch on a computer, it checks and ensures that all its components are working properly & if something is wrong with any component it warns the user. The process is called POST (Power on Self Test).
Next ROM searches for operating system in disks drives (CDD or FDD ) and then on Hard disk. When operating system is found it is loaded into RAM now computer is ready to be used. It is called booting. It is of two types:
Cold Booting:- On/Off the PC.
Warm Booting :- This is done by pressing alt + ctrl + del keys on the keyboard.
Note:- Rebooting should only be done when no other alternative is left.
Slide 11 : Bootable disk :- A Floppy or CD containing the backup of operating system files is called a bootable disk. It is helpful when computer doesn’t find operating system on its own drives and doesn’t boot.
Utilities :- Programs/Software that fill the gap between user needs and function abilities of operating system. E.g. – Anti virus, Network resource management software.
Virus and Anti-Virus : Virus and Anti-Virus Virus:- A program written in any computer language which cause damage to data, information or hardware of computer. It is destructive software, capable of replicating by copying itself. Computer having virus is called infected computer. It can spread with the help of CDs , Floppy, Internet and most commonly by USB Pen drives. It can do:
Erase data from hard disc.
Increase size of command files by several 1000 bytes.
Effects the hardware components.
E.g. Amoeba, Data Crime, April 1st, Yankee, Doodle, I love
you etc.
Anti-Virus: - Programs used for preventing virus are called Anti-Virus Software e.g. Norton, Zone Alarm, MacAfee etc.
Programming Language : Programming Language To perform a specific task on computer one has to write instructions. Sequence of these instructions is called programs. A person who writes these programs is called programmer. Computer language used to write these programs is called programming language.
A set of program is called Software and a person who makes software is called software developer. Three main categories of Programming Language:
Machine Language.
Assembly Language.
High Level Language.
Slide 14 : Machine Language: Instructions & codes written in binary or decimal. It can be directly understood by machine without any translating program. It is machine dependent and difficult to write.
Assembly Language: Programs written in Alphanumeric symbols instead of 0’s & 1’s e.g. ADD for Addition, SUB for Subtraction & CMP for Comparison. These symbols are called mnemonics. It is easy to write & machine dependent/oriented.
An translating program is needed to translate assembly language program in machine code for execution. This software is called Assembler.
High Level Language (HLL): Machine & Assembly Language were machine dependent & low level language whereas HLL are problem oriented so more efficient & no machine dependency. It is machine independent & easy to learn & use.
E.g. BASIC, PASCAL, FORTRAN, COBOL, C, PL/1, PROLOG etc.
Now a days Object Oriented (O.O.) PLs are widely used as they are easy to use, efficient, machine independent & more user friendly. E.g. C ++, C#, VB, VB.Net, JAVA etc
The translating program used for HLL is called Compiler which make HLL understandable to machine which only understands binary or decimal.
Multimedia Computer : Multimedia Computer The word Multimedia refers to different communication media such as Audio, Video, Text, Graphics etc. Some Multimedia equipments are:
Video Player.
CD Player.
Musical Player.
Monitors
DVD Players etc.
A PC equipped with above is called Multimedia computer.
Uses of Multimedia PC : Uses of Multimedia PC Entertainment.
Software Training.
Fashion Designing.
Education.
Advertisement.
Marketing.
Communication.
Publishing.
Windows have following Multimedia Tools : Windows have following Multimedia Tools Sound Recorder.
Volume Control.
CD Player/Writer.
Window Media Player.
Window Movie Maker.
Communication & Computer : Communication & Computer Data communication means linking the computer systems both locally and throughout the networks and transmitting speech, numerical information, text & images through digital transmission.
Necessary Elements for Data Communication : Necessary Elements for Data Communication Circuits & Networks for transmission.
Hardware & Software which support the data communication function.
Procedure for detecting & recovering from errors.
Rules/Protocols for disciplined exchange of information.
Protocol: A set of agreed rules between communicating computers.
Data Transmission : Data Transmission The movement of information through appropriate media is called Data Transmission. It is done as following:
Electrical signal carried along a conductor.
Optical signals through OFC (Optical Fiber Cable)
Electro Magnetic waves or Infra Red (IR) through space.
Types & Methods of Data Transmission : Types & Methods of Data Transmission Data transmission can be divided into two types:
Internal Data Transmission: It refers to transmission of data within a computer. It is done with help of buses which are of three types:
Data Bus: It moves the data from one location to another within a computer.
Address Bus: It moves the destined address of data within a computer.
Control Bus: These carry control signals from the control unit to all components of the computer
B) External Data Transmission : B) External Data Transmission It refers to transmission of Data to peripheral devices (e.g. printer) of computer system or transmission of data to remote computers. It is done with the help of communication links:
Communication Links: Ways/methods of inter connecting computers.
Communication Links : Communication Links Paired wires:
Digital/Analog.
Slow Speed < 2 Mbps.
2/3 KM Range.
Less Cost.
2. Coaxial Cable:
Digital/Analog.
Medium Speed 50 Mbps.
5/6 KM Range.
Moderate Cost.
Optical Fiber:
Digital
Fast 200 Mbps.
26 KM Range.
Moderate Cost Microwave:
Digital/Analog.
Slow speed < 3 Mbps.
80 KM. Range.
Low Cost.
Infra Red:
Digital.
Slow speed < 3 Mbps.
1 M Range.
Low Cost.
Laser:
Digital.
1 to 3 Mbps.
2 M Range.
Low Cost
Conversion Codes : Conversion Codes As we know that input data of any type is to be converted in binary by input unit for further processing by CPU. Why?
Conversion codes are used to convert input data in binary by input unit. These are of following types:
BCD
EBCDIC
ASCII
BCD codes:Binary Coded Decimal codes : BCD codes:Binary Coded Decimal codes Used to represent a decimal number
Each decimal number is represented by four binary digits e.g.
(3)10=(0011)2
(56)10=(0101 0110)2
Difference between BCD codes and Binary equivalents : Difference between BCD codes and Binary equivalents The binary equivalent of decimal number
(43)10=(101011)2
Where as BCD will be
(43)10=(0100 0011)2
Uses of BCD code : Uses of BCD code The BCD codes are used where decimal information is directly transferred into or out of a digital system e.g.
Electronic calculators
Digital voltmeters
Frequency counters
Electronic counters etc.
Modern computers do not use BCD numbers as they have to process text and other type of data also.
BCD is 6-bit code and supports only 64 characters.
EBCDIC: Extended Binary Coded Decimal Interchange Code : EBCDIC: Extended Binary Coded Decimal Interchange Code 8-bit code and supports 256 different characters
Supports printable/non-printable characters (spacing, movement of cursor)
Hexadecimal number system is used for shortcut notation
Saves memory 1:4
ASCII Code: : ASCII Code: ASCII stands for American Standard Code for Information Interchange
Popular in data communication
used to represent data internally in micro-computers (PCs)
ASCII code is of two types:
1. ASCII-7 2. ASCII-8
Types of ASCII Code : Types of ASCII Code ASCII-7 is a 7 bit code and supports 2*2*2*2*2*2*2=128 different characters
ASCII-8is a 8 bit code and supports 2*2*2*2*2*2*2*2=256 different characters and the first bit is always 0
Uses Hexa decimal to save memory in 1:4
Factors to be considered while buying a P.C. : Factors to be considered while buying a P.C. CPU: Higher performance, compatibility, upgradeability are the main factors. Higher the generation, better the CPU. e.g Pentium-IV is always better than P-II or P-III. The latest CPUs are Core2duo and Dual core
Pentium MMX means Pentium processor with multimedia extension.
Clock Rate (MHz/GHz): Higher is always better. 1GHZ clock rate means that the CPU can execute 1000*1000*1000 instructions per second
Slide 32 : RAM: (MB/GBs)
The operating systems like Windows require at least 4 MB RAM only for booting. More the applications required to run simultaneously, more the RAM is required. More the RAM, faster the computer. Today’s PCs have 1GB or 2GB RAM.
Cache: (MB)
This memory is in addition to RAM and is of two types:
L1 Cache--?On-chip memory, more L1 cache means higher speed of computer
L2 Cache--?Off-Chip memory and assists L1 cache, may increase the speed of system upto 45%
Slide 33 : Hard Disc Drive (GB): 80-120 GB Hard Disc may be sufficient although these days 250 GB and 500 GB hard disc are available. Hard Discs speed is also to be considered. 7200 r p m is better than 3600 r p m.
Video Card: also known as VGA card. It should have 1-2 MB VRAM and should be PCI compliant.
PCI: Peripheral Component Interface
Slide 34 : CD ROM/DVD ROM speed:
More speed of CD or DVD drive means faster installation of software and running of applications on CDs or DVDs.
CD/DVD drive speed is indicated as 24X,40X or 48X
MMX Processor: MMX stands for multimedia extension. Pentium processor with MMX property is better for enjoying media rich applications like video games etc.