4572-4770_Ch1IntroductiontoComputer

Chapter 1Introduction to Computer

Computer Fundamentals by Dr. Anita Goel

Contents

What is a Computer Characteristics of Computer History of Computer Generations of Computer Classification of Computers Computer System Input-Process-Output Concept Components of Computer Hardware Application of Computers

Chapter-1: Introduction to Computer 2


What is a Computer

Computer is an electronic device that accepts data as input, processes the input data by performing mathematical and logical operations on it, and gives the desired output.

Two categories

Digital Computer

Analog Computer


Characteristics of Computer

Speed

Accuracy

Diligence

Storage capability

Versatility


History of Computer

Calculating machines – ABACUS Napier’s Bone Slide Rule Pascal’s Adding and Subtraction Machine Leibniz’s Multiplication and Dividing Machine Punch card system Babbage’s Analytical Engine Hollerith’s punched card tabulating machine


Generations of Computer

Evolution of computer to the current state

Five generations

Categorized on the basis of Technology used by them (hardware and software)

Computing characteristics (speed - number of instructions executed per second)

Physical appearance

Their applications


Generations of Computer


First Generation: 1940-56 Vacuum tubes, magnetic drums,

punched cards, paper tapes and printouts

Machine language Computation time in milliseconds Enormous in size For scientific applications Examples

UNIVersal Automatic Computer (UNIVAC)Electronic Numerical Integrator And Calculator (ENIAC)Electronic Discrete Variable Automatic Computer (EDVAC)


Punched Card

UNIVAC


First Generation: 1940-56


Time magazine ran the cover story "The Brain Builders" on Tom Watson, Jr., and IBM on March 28, 1955. IBM had just installed a model 702 Electronic Data Processing Machine in its Monsanto HQ in St. Louis, called "the giant brain." It had 2,500 tubes, did 7,200 logical operations per sec., with punch card and magnetic tape storage. It was the result of IBM slogan "Think" and Tom Watson, Jr., who took over presidency of IBM in 1952, and who led the battle to automate American business. IBM had orders for 14 model 702s at a monthly rental of $20,000, and had delivered 19 of the earlier model 701. The AEC had 3 model 701 machines, the Weather Bureau had one model 701. IBM had just delivered the NORC computer to the Navy, and had 109 orders for the new 704 and 705 models that will cost IBM $1 million each to build.

Source: http://history.sandiego.edu/GEN/recording/watson.html


Second Generation: 1956-1963 Transistors, magnetic core

technology , magnetic tapes and magnetic disks, concept of a stored program

Assembly language Computation time in

microseconds. Reduced size compared to first

generation computers Cost of commercial production

was very high Examples

PDP-8IBM 1401CDC 1604



Third Generation: 1964-1971 Integrated Circuit (IC) chips,

keyboard, Monitor Operating system, High-level

languages Computation time in

nanoseconds Quite small compared to second

generation computers Accessible to mass audience Produced commercially Examples

IBM 370 PDP 11


DEC PDP 11


Fourth Generation: 1971-Present LSI, VLSI, Microprocessor, PC,

Semiconductor Memory, Linking of computers, Mouse and Handheld Devices

GUI, OS like MS-DOS and MS-Windows

High-Level Programming Languages Computation time in picoseconds Smaller than computers of previous

generation Widely available for commercial

purposes PC for home user Examples

Intel 4004 chip was the first MicroprocessorIBM, Apple’s Macintosh



Fifth Generation: Present & Next Using Artificial Intelligence (AI)

Expert Systems (ES), Natural Language Processing, Speech recognition, Voice recognition, Robotics etc.

Capable of learning and self organization

SLSI, large memory

Parallel processing



Classification of Computers

Categories based on Size

Type

CategoriesMicrocomputers

Minicomputers

Mainframe computers

Supercomputer



Microcomputer Small, low-cost, single-user digital computer. Include

Desktop computer or PC: Stand-alone machine, not very expensive, for single user.

• Manufacturers: Apple, Microsoft, HP, Dell, Lenovo, …Notebook or laptop: Portable , small size, costlier than desktopNetbook: Smaller notebooks, low weight, low cost, for web-based applications.Tablet computer: Input via stylus or pen, Portable Handheld computer or PDA: Held on top of palm, small in size, uses pen or stylus, limited memory, less powerful. Smart phones: Cellular phones (function both as phone and small PC), to access e-mail, download music, play games etc.

• Manufacturers: Blackberry, Apple, HTC, Nokia, LG, Motorola



Minicomputers

Multi-user systems. High processing speed High storage capacity than the microcomputers. Support 4 to 200 users simultaneously. Examples

PDP 11

IBM (8000 series)



Mainframe computers Multi-user, multi-programming , high-performance

computers. Very high speed, large storage capacity Used in centralized databases. Access via dumb terminal, an intelligent terminal, or

PC. Dumb terminal: No own data storage & processing. Has I/O device only. Intelligent terminal: Has the I/O device, can do processing, but, cannot store data of its own. Use processing power and storage facility of mainframes

Examples CDC 6600IBM ES000 series.



Supercomputers

Fastest and the most expensive machines. High processing speed Speed in FLOPS (FLoating point Operations Per

Second). Used for highly calculation-intensive tasks -

weather forecasting, climate research, molecular research, biological research, nuclear research

ExamplesIBM Roadrunner, IBM Blue gene

Intel ASCI red.

PARAM in India



Computer System

Four partsHardware: Mechanical parts of computer, e.g. Keyboard, monitor, hard disk drive etc.

Software: Set of instructions (Program) and documentation. Instructs the computer about the task to be performed.

Data - Isolated values or raw facts.• Provided as input to computer for processing

Users -People who write computer programs or interact with computer.



Input-Process-Output Concept


The concept of generating output information from the input data

Storage: Stores input data, instructions and output; permanently on disk


Components of Computer Hardware


CPU

Registers

Control Unit

Arithmetic and Logic

Unit

Input Unit Output Unit

Memory UnitMemory Unit


Components -Computer Hardware Three main components I/O Unit - user interacts with computer via I/O unit

Input unit accepts data from the user (Devices - keyboard, trackball, mouse)Output unit provides processed data to user (Devices - monitor and printer)

CPU - Controls, coordinates , supervises operations of computer.

Arithmetic Logic Unit (ALU) - performs arithmetic and logic operations on input data. Control Unit (CU) - controls overall operations of computerRegisters - temporary storage of data, instructions, addresses, intermediate results

Memory Unit – Stores data, instructions etc.Main memory or Primary memory - Stores data, instructions, intermediate results ,output, temporarily Secondary memory – Stores data, programs, output permanently

• Magnetic disks, optical disks and magnetic tapes



Application of Computers



A Pictorial view of History of Computers


Computer Fundamentals by Dr. Anita Goel Chapter-1: Introduction to Computer 25

1965

1950 It shows the Harvard Mark III depicted as a naval officer with one eye, a cap and two arms with hands, one holding a piece of paper tape and the other pressing a key on a teletype. The Mark II is shown with dials, buttons and keys.


1983 1984


1984 1994


1996 1999


2002 2006


2010

What are the other milestone’s you can recall?


Thank You


4572-4770_Ch1IntroductiontoComputer

Documents

magnetic tapes

intermediate

artificial

intelligent

dumb terminal

tom watson

anita goel

computer fundamentals