Computer System

COMPUTER

SYSTEM

Objectives:• Familiarize themselves with the

computer.

• Identify the elements of the computer system.

• List the classifications of computers.

• State the capabilities and limitations of computers.

• Discuss the history of computers.

Introduction to Computers:• Computer System is an electronic

device which consists of several components that together provide the capability of executing a stored program.

- a device that accepts data, processes and stores these , and procedures a result. It performs the basic function such as:

input process storage output

Basic Computer Functions

STORAGE

INPUT PROCESS OUTPUT

Typically, a Computer System Consists: Input Devices – allows users to input data for

processing.

Storage Devices – whether the processed information are stored

Central processing unit – known as , (CPU) which interprets and executes data or instruction.

Output Devices – where the outcomes are displayed.

Three main elements of a Computer System: Hardware – refers to the physical components

of a computer that can actually touch, such as keyboard, monitor, central processing unit (CPU), mouse and printer.

Software – is untouchable, are set of instructions used to direct the hardware on how to turn data into useful information for people to use.

Peopleware – the most important factor in a computer system. Because, they manipulate and program the computer system to make it useful.

The Elements of a Computer SystemA. HARDWARE

- Hardware may be classified into input devices, output devices, the central processing unit (CPU) and secondary storage.

1.Input Devices - input hardware consists of external devices, components of outside of the computer’s CPU, that provides information and instructions to the computer.

Input devices

INPUT DEVICES DESCRIPTION

A Computer keyboard has alphabetic, numeric and function keys for the entry of information.

Mouse is a handheld pointing device, is used to move a pointer on the screen. This device is commonly used in PC

Input devices

INPUT DEVICES DESCRIPTION

A Joystick is a pointing device, that is used for playing games.

A scanning device translates images of text, photo and other graphics into digital form. The digitized image can then be manipulated or reproduced using the computer

Input devices

INPUT DEVICES DESCRIPTION

A Digital Camera capture images in electronic form for immediate viewing on computer screen or TV. These images can be stored and manipulated using computers.

A Fax machine or facsimile transmission machines, scans hardcopy and transmit data to another fax machine using telephone lines.

The Elements of a Computer System2. Output Devices

- Output Hardware ,consists of devices which communicate the result of processing back to the user by converting electrical signals from the Arithmetic/Logic Unit into a form recognizable by a human operator. It includes the following:

Video displaysHigh speed printers Console type writers

Output devices

Output Devices DESCRIPTION

Monitors display images using grids of dots called pixels. It is the most common output device that shows information on the screen when you type.

A printer is a common equipment used to output information from the computer. The information on the monitor’s screen is transferred or printed in a paper. Three types of printers : dot matrix, laser and inkjet printers.

Output devices

Output Devices DESCRIPTIONA plotter is an output device used to produce high quality drawings. It can draw curved lines just like a pen on a paper. It requires lots of memory to store on a highly accurate images.

Speakers produce sound output from the computer. One form of speaker is a headphone, which maybe used individually. Speakers allow the user to listen to high quality music through the computer.

The Elements of a Computer System3. Central Processing Unit

- the processing and conversion of data from input to output is done in the Central Processing unit. Its main function is to perform arithmetic and logical operations on data taken from the primary storage. The five basic components of the CPU:

Main Storage Registers, Control UnitBuses, Arithmetic logical Unit

Basic CPU components

Basic CPU components

DESCRIPTION

Main Storage The main storage (also called as memory or primary storage) is where instructions and data are stored while processing is done. The data stored are usually given unique addresses or memory locations to facilitate storage and retrieval .Two types of memory:• RAM (Random Access Memory) • ROM (Read Only Memory)

RAM (Random Access Memory)

RAM (Random Access Memory) is the part of the memory that the computer uses to store given instructions which can later be changed or erased.

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Basic CPU components

DESCRIPTION

The RAM requires electric Current to retain information on it. All information stored in it are lost or erased when the computer power is turned off or interrupted. This kind of memory is volatile.

ROM (READ ONLY MEMORY) ROM (Read Only Memory) contains stored instructions that a computer requires to be able to do its basic routine operations. This kind of memory is non- volatile. And the instructions are still hold even the power is interrupted or turned off.

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Basic CPU components

DESCRIPTION

Registers The Registers are the part of the CPU that function as fast accessed temporary memory locations. The bits of information taken from the main memory and those that will be placed in the main memory are temporarily held in the registers while computations are being performed.

Buses Buses are bundles of tiny wires that serve as the communication path between components of the CPU. The three most important buses are the address, data and control buses.

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Basic CPU components

DESCRIPTION

ALU (Arithmetic Logical Unit)

The Arithmetic Logical Unit (ALU ) performs all the arithmetic and logical calculations of the CPU. The arithmetic operations consist of addition, division, subtraction and multiplication. Logical calculations involves comparison of two or more numbers.

CU (Control Unit) The control Unit is responsible for directing the flow of instructions and data within the CPU. It fetches the instructions from the main memory for execution in the CPU.

The Elements of a Computer System4. Secondary Storage

- Secondary Storage is where the data are stored permanently. The two classes of Secondary Media are:

Direct Access Media - supports sequential or random

access where data can be accessed directly.

Sequential Access Storage - it is where data are accessed in a specific order.

Example of A Direct Access Media.

FLOPPY DISK

Example of A Sequential Access Media.

MAGNETIC TAPE

Secondary Storage Media

Secondary Storage Media

DESCRIPTION

MAGNETIC TAPE A sequential access Storage media where blocks of data are stored serially along the length of the tape and can only be accessed in a serial manner.it is still popular for a long – term/ high. Volume storage even though the it is the slowest in terms of retrieval of data.

MAGNETIC DISK the magnetic disk is a direct access storage media which , like a phonograph record, is divided into tracks and sectors. Common types : hard disks and Floppy disks.

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Secondary Storage Media

DESCRIPTION

HARD DISKS Hard disks are stacks of rigid magnetic disks., that are permanently mounted in a unit that may be internal or external to the computer and are often used as virtual memory or extension of RAM. They have relatively high capacity and fast retrieval speed but very fragile.

FLOPPY DISKS Floppy disks are much slower than the hard disks and have less capacity ranging from 1.44 mb to 200 mb. A newcomer to the scene is the super floppy disks which has a capacity of 120 mb.

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Secondary Storage Media

DESCRIPTION

OPTICAL DISKS An optical disk has the same technology as the music CD. They usually contain about 650 mb of data. Some common forms of optical disks are CD – ROM, CD – R , CD- RW, DVD, Magneto Optical Disk.

Compact Disk – Read Only Memory (CD - ROM)

CD – ROM is a non erasable disks that store computer data, usually in standard system uses 12 – cm diameter with CD recordable.

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Secondary Storage Media

DESCRIPTION

Digital Versatile Disk (DVD)

Contains digitized and compressed video information, as well as large volumes of other digital data in both 8 – and 12 cm. diameter disks. It also has its own Read – Only (DVD), Recordable (DVD - R) and Rewritable (DVD -RW) versions.

Magneto – optical disk the Magneto – optical disk (MO), a hybrid between magnetic disk and optical disk, uses optical technology for read and magnetic recording technique assisted by optical focusing. It is cheaper and longevity cost per megabyte.

The Elements of a Computer SystemB. SOFTWARE

- The set of instructions or programs that tells the computer how to do specific task is called a software. A software is categorized as System software or Application software.

1.System Software- Performs task necessary to the efficient management of the hardware. It refers to computer programs or library files whose purpose is to help run the computer systems.

System Software includes:

Operating system

Utility programs

Compilers

Interpreters

System Software

Output Devices

Description Example

Operating System

The operating system is a set of programs which controls and coordinates the whole operation of the computer system. It is the first program loaded in the memory to ensure the convenience of the user and the efficiency of the whole computer systems.

OS/2 UNIX LINUX DOS/MVS MacOS JavaOS Windows NT Windows XP Windows CE Windows 2000 Windows 98 Windows 95 Windows 3.1 Novel Netware

System Software

Output Devices

Description Example

Utility Programs

Utility Programs are system software service programs that help the operating system efficiently manage files and do housekeeping functions. These include programs for data backup, data recovery, virus protection, data compression, data security and file fragmentation.

Norton utilities Central point

anti virus Megz lock Pretty Good

privacy McAffee Virus

Scan Dr. Solomon’s

Anti virus Guard DogSurfinShield

System Software

Output Devices

Description Example

Compilers and Interpreters

Compilers and Interpreters are programs that translates high-level language programs into object code. Compilers translate the whole program as an object code at once while interpreters translate it one statement at a time.

Cobol compiler Fortran

compiler C compiler Basic

interpreter Prolog

interpreter Java interpreter

The Elements of a Computer System2. Application Software

- Are programs that help solve and meet user problems and needs directly. Application software can serve as productivity tools; assist in graphics and multimedia projects; support home, personal, and educational use , and facilitate communication.

Application Software

Productivity Software

Description Example

Word Processing Software

Allows users to create and manipulate documents that text and graphics.

Microsoft word Word perfect Word star

Spreadsheet software

Allows user to enter data into rows and columns and perform computations or make graphs based on the data given.

Microsoft Excel Corel Quattro pro Lotus 123

Application Software

Productivity Software

Description Example

Database Software

Allows user to manage data by organizing these in database tables.

Microsoft Access Visual fox pro File Maker Pro Dbase Oracle MS SQL

Presentation Graphics software

Allows users to create presentations that communicate ideas, messages and other information through slide show.

Power point Photoshop Adobe Illustrator Free Hand Corel Draw

Application Software

Productivity Software

Description Example

Personal Information

Manager Software

Allows user to maintain an address book and appointment calendar and make use of notepad to record ideas and reminders.

Outlook

Project Management

Software

Allows users to plan, schedule, track, and analyze progress of a project.

Harvard Project Manager

Microsoft project

Application Software

Graphics & Multimedia

Description Example

CAD(Computer Aided Design)

software

Allows user to create engineering, architectural and scientific designs.

Autovis AutoCad

Desktop Publishing software

Allows user to design and produce page layout and sophisticated documents.

Adobe pagemaker

quarkXpress Microsoft

publisher

Application Software

Graphics & Multimedia

Description Example

Web page design software

Allows user to design and produce webpages

Dream weaver Frontpage Hyperstudio

Image editing software

Allows user the capability to modify existing images.

Photo draw Director

photoshop

Application Software

Graphics & Multimedia

Description Example

Video / audio editing software

Allows user to modify video / audio segments

Author ware

Multimedia authoring software

Allows user to create electronic interactive presentations that can include text, images , video, audio and animation.

Illustrator Hyperstudio Flash toolBook

The Elements of a Computer SystemC. PEOPLEWARE

-The skilled workers in the information technology field are called peopleware.

- the major compositions of these IT professionals are the management group, systems and procedures group, programming group and the computer operations group.

Classifications of Computers

- Computers maybe classified into the following:

According to capacity

According to purpose

According to the type of processing

Classifications of Computers

- Computers maybe classified into the following:

According to capacity- their ability to perform a task.

According to purpose - their goals and aims for variety of

task.

According to the type of processing- their special uses in different fields of work.

Capabilities and Limitations of Computer

Enumerated below are some of the computers can do:

1.They can do repetitive and routine work.

2.They have the speed to process voluminous data in a flash, resulting in greater productivity and less manpower needs.

3.Computers are reliable and accurate.

4.They can store and recall tremendous amount of information

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5. Computers have a self checking capability.

6. Computer can be self – operating. All data are fed into the computer memory, processing and output are given without human intervention.

7. The can do remote processing. Computers can process any data coming from anywhere , even from any remote place.

History of Computing

- 2000 B.C ABACUS - 1617 Logs and Bones - 1642 Arithmetic Engine - 1670 Stepped Reckoner - 1800 Jacquard’s Loom - 1822 Difference Engine & Analytical Engine

First Female Computer Programmer

- 1827 Boolean Algebra - 1884 Punched Card tabulating machine - 1886 1st commercial Mechanical

Machine - 1928 CRT - 1931 Z1 Computer

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- 1939 ABC Computer - 1943 Colossus - 1944 Mark 1 - 1945 1st Computer Bag - 1946 ENIAC EDVAC - 1951 UNIVAC Microprogramming - 1952 Integrated Circuit IBM 701 - 1954 Fortran - 1956 Hard Drive for mainframe

Computer- 1958 First IC Built

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- 1960 PDP – 1 - 1962 Mouse - 1964 BASIC

Word ProcessingASCIICDC 6600

- 1965 Moore’s Law-1966 Magnetic Bubble-1967 First Floppy Disk-1968 Computer on a chip

Pascal programming - 1972 C , diskette, 1st electronic pocket computer - 1973 Ethernet

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- 1974 Personal computer - 1975 BASIC - 1976 Apple 1 Computer - 1978 VisiCalc - 1979 WordStar - 1980 MS DOS C++ - 1981 IBM PC - 1983 Lotus 1 -2 -3 - 1984 Apple Macintosh - 1985 Windows

Page Maker - 1989 www

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- 1974 Personal computer - 1975 BASIC - 1976 Apple 1 Computer - 1978 VisiCalc - 1979 WordStar - 1980 MS DOS C++ - 1981 IBM PC - 1983 Lotus 1 -2 -3 - 1984 Apple Macintosh - 1985 Windows

Page Maker - 1989 www

“COMPUTER SYSTEM”END OF