Computers HW and SW

8/7/2019 Computers HW and SW

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Information System:Hardware and Software

Archana Mehta



Contents

History of Computers

Evolution of IT Infrastructure

Computer System: Hardware Computer System: Software

Programming ± Languages

Types of Computer

Network



History of Computers

Then Now



Computer Evolution

1642 Blaise Pascal ± mechanical adding machine. Babbage¶smachine was the 1st general purpose mechanical digital computer.Later his analytical engine had a memory.



Computer Evolution

Early 1800¶s Jacquard ± uses punch cards to control the patternof the weaving loom.

1832 Charles Babbage - invents the Difference Engine

1890 Herman Hollerith ± invents a machine using punch card to

tabulate info for the Census. He starts the company that wouldlater be IBM.



Computer Evolution

1946 ± Mauchly and Eckert created the ENIAC (ElectronicNumerical Integrator And Computer ) computer, first electroniccomputer is unveiled at University of Pennsylvania:

Miles of wiring

18,000

vacuum tubes Thousands of resistors and switches

No monitor

3,000 blinking lights

Cost $486,000

100,000 additions per second

Weighed 30 tons

Filled a 30x50 foot room

Lights of Philadelphia would dim when it booted up



Computer Evolution

1950s -

Vacuum Tubes were the components for the electroniccircuitry

Punch Cards main source of input Speeds in milliseconds (thousands/sec)

100,000 additions/sec.

Used for scientific calculations



Computer Evolution

1960s -

Transistors were electronic circuitry (smaller, faster,more reliable than vacuum tubes)

Speeds in microseconds (millionth/sec) 200,000 additions/sec.

Computers In Businesses: Emphasis on marketing of computers to businesses

Data files stored on magnetic tape

Computer Scientists controlled operations



Computer Evolution

Late 60¶s Early 70¶s

Integrated circuit boards

New input methods such as plotters, scanners

Software became more important Sophisticated operating systems

Improved programming languages

Storage capabilities expanded (disks)



Computer Evolution

1970¶s Integrated circuits and silicone chips lead tosmaller microprocessors



Computer Evolution

Late 80¶s to Current

Improved circuitry ± several thousand transistorsplaced on a tiny silicon chip.

Pentium chip named by Intel

Modems ± communication along telephone wires Portable computers: laptops

Increased storage capabilities: gigabytes

Emphasis on information needed by the decisionmaker.



Evolution of IT Infrastructure Electronic Computing Machine Era ± 1930-1950:

Efficient for accounting tasks. Large and cumbersome machines. No programmers, and a human machine operator was the

operating system, controlling all system resource.

General Purpose Mainframe and Mini computer era: 1959 topresent: Introduced by UNIVAC computers and the IBM 700 Series. IBM dominated mainframe computing from 1965 onwardand still dominates this$27 billion global market in 2004.

Personal computing Era (1981 to present)

At first using the DOS operating system, a text-based commandlanguage, and later the Microsoft Windows operating system, theWindows operating system software on a computer with an Intelmicro- processor (Wintel PC computer) became the standarddesktop personal computer.



Evolution of IT Infrastructure Client/Server era (1983 to present)

Desktop or laptop computers called clients are networked toserver computers that provide the client computers with a varietyof services and capabilities. Computer processing work is splitbetween these two types of machines. The client is the user pointof entry, whereas the server provides communication among the

clients, processes and stores shared data, or manages networkactivities. The term server refers to both the software applicationand the physical computer on which the network software runs.The server could be a mainframe, or a more powerful versions of personal computers.

Enterprise Internet computing era (1992 to present)

Networking standards and software tools integrate disparatenetworks and applications throughout the firm into an enterprise-wide infrastructure.



Evolution of IT Infrastructure Cloud computing (2000 to present)

Cloud computing is Web-based processing, whereby shared resources,software, and information are provided to computers and other devices(such as smartphones) on demand over the Internt. Details are abstractedfrom the users, who no longer have need for expertise in, or control over,the technology infrastructure "in the cloud" that supports them .

This frequently takes the form of web-based tools or applications thatusers can access and use through a web browser as if it were a programinstalled locally on their own computer. Typical cloud computing providersdeliver common business applications online that are accessed fromanother Web service or software like a web browser, while the softwareand data are stored on servers.

The major cloud service providers include Salesforce, Amazon andgoogle. Some of the larger IT firms that are actively involved in cloudcomputing are Fujitsu, Microsoft, Hewlett Packard, IBM, VMware and Dell.




Cloud Computing Conceptual Diagram



IT Infrastructure Ecosystem



Computer System: Hardware



Computer Systems - Hardware

Hardware: The internal structure of computers, how they operate and how

they are used in solving computerproblems.



Hardware Components

Memory

CPU

Input

Devices

Output

Devices



Components of Hardware1. CPU - central processing unit is the brain of the computer.

Interprets and executes instructions, controls input and output. It is anintegrated circuit or ³chip´

CPU speed is measured by the number of completed instructionscycles per second. Currently, CPU speed ranges from 600 MHz to 4 gigahertz (GHz or billion cycles per second).

The three major components of the CPU are:Arithmetic Unit (Computations performed)

Accumulator (Results of computations kept here)Control Unit (Has two locations where numbers are kept)

Instruction Register (Instruction placed here for analysis)Program Counter (Which instruction will be performed next?)

Instruction Decoding Unit (Decodes the instruction)

Motherboard: The place where most of the electronics including theCPU are mounted.

CPU types: Intel Pentium II, III, IV Intel Celeron AMD Athlon



Components of Hardware2. Memory (Primary): Stores information. Capacity measured in

Megabytes/Gigabytes and speed in Nanoseconds. Classificationof Memory:ROM (Read only Memory): Small, instructions are installed

permanently and check the computer resources.R AM (Random Access Memory): Main memory, temporary,

programs and data are stored while being processed.

3. Input devices: Units that gather information and transformthat information into a series of electronic signals for thecomputer. Keyboard, Mouse, Touch Tone Telephone, Touchscreens, Bar Code Scanner, Voice Recognition, Light Pen, ImageScanner etc.

4. Output devices: Devices that display, print or transmit theresults of processing from the computers memory.. Monitor,Printer, Voice and Music Speakers, Synthesizers



Auxiliary Storage Devices Used to keep data when the power to the computer is turned off.

Magnetic storage devices store data by magnetizing particleson a disk or tape. They have a limited life-span of 1 to 5 years,depending on the device

Optical storage devices store data as light and dark spots on

the disk surface. They have an unlimited life-span. Hard disk Drive: Capacity is measured in Gigabytes (GB) is

magnetic storage device, is permanently installed. Used to storeapplication software, utilities and data.

Floppy disk drive capacity is 1.4 MB to 2 MB, magnetic.

CD-ROM Drives: capacity is 600 to 700 MBs.

Most mass-produced commercial softwareis packaged on a CD. Optical storage device.

Other types are: Zip Drive, Tape Drive,

DVD Drive



Computer System: Software



Computer System: Software

Software: Instructions and associateddata, stored in electronic format, that

direct the computer to accomplish atask.



Layer Structure



Types of Software

General-Purpose

Programs

Application-Specific

Programs

SystemManagement

Programs

SystemDevelopment

Programs

ApplicationSoftware

Computer Software

SystemSoftware



System SoftwareSystem software: Systems software is the control software that

operates the hardware and allows the applications to run.Itincludes a combination of the following:

Device Drivers ± is a computer program allowing higher levelcomputer program to interact with hardware device

Operating System - Software that translates a computers

commands and allows application programs to interact with thecomputer¶s hardware

Servers - a computer program running as a service, to serve theneeds or requests of other programs (referred to in this contextas clients) which may or may not be running on the samecomputer

Utilities - designed to help analyze, configure, optimize and

maintain the computer Window System - basic support for graphics hardware, pointing

devices such as mice, and keyboards. The mouse cursor is alsogenerally drawn by the windowing system. Examples areMicrosoft Windows, Linux,



Programming SoftwareProgramming software is a set of tools that include:

Compliers - set of programs that transforms source code writtenin a programming language into another computer language(the target language, often having a binary form known as object

code) Debuggers

Linkers or link editor: a computer progran that takes one orobjects generated by a complier and combines them into asingle executable program

Text Editors ± type of program used for editing plain text file,

used for changing configuration files and programming languagesource coed



Functions of an Operating System

ResourceManagement

TaskManagement

User Interface

FileManagement

Utilities

and Other Functions

Managing memory, i.e. allocating memory to more than one programrunning simultaneously.

Interrupts, for Enter, Printer out of paper, or a hardware or softwaremalfunction.

Diagnostic checks on the system on Boot up, sending error messageswhere necessary.

Selecting and controlling peripheral devices through small Driver programs



Application SoftwareApplication software is Easy-to-use programs designed to perform

specific tasks.

Typical applications include: Business Software V

ideo Games Databases Mathematical software Spreadsheet Word Processing Decision Making Software Simulation software Telecommunications Medical software



Application SoftwareApplication software can be grouped into three categories: Generic:

general purpose for business; most common applications are Word Processing, Spreadsheet

& Database.

Most generic software for business comes in an integratedpackage such as: Microsoft Office Bespoke:

tailor made, specifically written for a specific application. An expensive but a perfect solution to a requirement when

there is no suitable package available. Often a one off piece of software written for a large

organisation as a perfect match to their needs Specific Task:

particular tasks for business; most common are payroll, CAD, and stock control. Cheaper to buy than separate packages



Trends in Computer Software

FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

User-WrittenPrograms

MachineLanguages

PackagedPrograms

SymbolicLanguages

OperatingSystems

High-LevelLanguages

DBMSFourth-GenerationLanguages

Microcomputer Packages

Natural &Object-Oriented

LanguagesMultipurpose

Graphic- InterfaceNetwork-EnabledExpert-Assisted

Packages

Trend: Toward Easy-to-Use Multipurpose Network-Enabled ApplicationPackages for Productivity and Collaboration

Trend: Toward Visual or Conversational Programming Languages andTools



Programming



Programming Language Programming languages allow a programmer to write instructions

that a computer can understand.

A program needs to be written in a language

There are many programming languages

Low-level, understandable by a computer

High-level, needs a translator! C++ is a high level programming language

A sequence of instructions

A program

(in computer language)

An algorthm

(in human language)



Levels of programming language

Machine binary language: for machine to understand

Low-level assembly language

Mnemonic names for machine operations

Explicit manipulation of memory addresses

Machine-dependent

High-level language

Readable

Machine-independent



Levels of programming language

² an example

Machine binary language Low-level assembly High-level



Software Development Major activities

Editing (writing the program)

Compiling (creates .obj file)

Linking with compiled files(creates .exe file)

Object files Library modules

Loading and executing

Testing the program

Compile

Link

Library routines

Other object files

Think

Edit

Load

Execute

Source Program



Categories of Programming Language

Machine Languages

Use binary coded

instructions

1001 10011100 1101

High Level Languages

Use brief statements

Compute X = Y + Z

Markup Languages

Use embedded

control codes

Assembler Languages

Use symbolic coded

instructionsLOD Y

ADD Z

Fourth Generation

Languages

Use natural statements

Object-Oriented

Languages

Define objects thatcontain data and actions

Document.write

(³Hi There´)

<H1>First heading</H><!ELEMENT Product

(#Item | manuf)>

SUM THE FOLLOWING

NUMBERS



Types of Computers



Types of Computer

Super Computers

Mainframe Computers

Minicomputers

Microcomputer/PC

Palmtop Computer

Calculator

Fast Expensive Complex Large

Slow Cheap Simple Small

Grouped according to speed, cost, size, and complexity.



Super Computers

Largest category of computer

Cost millions

Mostly used for scientific and industrial

research: NASA, Stock Exchanges



Mainframe

Large powerful computer often serving many connectedterminals.

Large expensive computer capable of simultaneouslyprocessing data for hundreds or thousands of users.

Used to store, manage, and process large amounts of datathat need to be reliable, secure, and centralized.

Usually housed in a closet sized cabinet.

Mini Computerare similar to mainframes...they are used by business and

government to process large amounts of information.



Personal Computer

are smaller and less powerful than theothers. They are used in homes, schools,and small businesses. 3 Main types of PC

are: Desktop

Portable (Notebook/Laptop)

Hand-Held (PDA - Personal Digi tal Assistant).



Server

A computer that processes request for HTML andother documents that are components of Web pages.

Purpose is to ´serve.µ

A computer that has the purpose of supplying i tsusers wi th data; usually through the use of a LAN(Local Area Network).



Network



Network

Two or more computersand other devices

that are connected, for the purpose of

shar ing data, programs

and other system resources.



Network



Types of Network

Local Area Network (LAN) ± a network locatedin a limited area.

LANs are found in most businesses.

Many campuses use LANs.

Wide Area Network (WAN) ± a network thatcovers a large geographical area.

Internet - largest of all networks.

All types of networks require special networkinghardware and networking software to allowdifferent computers to communicate with eachother.



Thank You

Computers HW and SW

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