LAB WORK 2 ( COMPUTER COMPONENTS )

Computer Components

Computers come in all types and sizes. There are primarily two main sizes of computers. They are:

• Portable
• Desktop

The portable computer comes in various sizes and are referred to as laptops, notebooks, and hand-held computers. These generally denote different sizes, the laptop being the largest, and the hand-held is the smallest size. This document will mainly talk about the desktop computer although portable computer issues are also discussed in various areas.

Computers are made of the following basic components:

1. Case with hardware inside:
1. Power Supply - The power supply comes with the case, but this component is mentioned separately since there are various types of power supplies. The one you should get depends on the requirements of your system. This will be discussed in more detail later
2. Motherboard - This is where the core components of your computer reside which are listed below. Also the support cards for video, sound, networking and more are mounted into this board. 
1. Microprocessor - This is the brain of your computer. It performs commands and instructions and controls the operation of the computer.
2. Memory - The RAM in your system is mounted on the motherboard. This is memory that must be powered on to retain its contents.
3. Drive controllers - The drive controllers control the interface of your system to your hard drives. The controllers let your hard drives work by controlling their operation. On most systems, they are included on the motherboard, however you may add additional controllers for faster or other types of drives.
1. Hard disk drive(s) - This is where your files are permanently stored on your computer. Also, normally, your operating system is installed here.
2. CD-ROM drive(s) - This is normally a read only drive where files are permanently stored. There are now read/write CD-ROM drives that use special software to allow users to read from and write to these drives.
3. Floppy drive(s) - A floppy is a small disk storage device that today typically has about 1.4 Megabytes of memory capacity.
4. Other possible file storage devices include DVD devices, Tape backup devices, and some others.
3. Monitor - This device which operates like a TV set lets the user see how the computer is responding to their commands.
4. Keyboard - This is where the user enters text commands into the computer.
5. Mouse - A point and click interface for entering commands which works well in graphical environments.

Computer of Classification

         1)   According to Size

         2)   According to Technology  

         3)   According to Purpose

         4)   According to size

•      Supercomputers
•      Mainframe Computers
•      Minicomputer
•      Workstations
•      Microcomputer or Personal Computer

Supercomputers : are widely used in scientific applications such as aerodynamic design simulation, processing of geological data.

•  Supercomputers are the most powerful computers. They are used for problems requiring complex calculations.

•  Because of their size and expense, supercomputers are relatively rare.

•  Supercomputers are used by universities, government agencies, and large businesses.

Mainframe Computers: are usually slower, less powerful and less expensive than supercomputers. A technique that allows many people at terminals, to access the same computer at one time is called time sharing. Mainframes are used by banks and many business to update inventory etc.

• Mainframe computers can support hundreds or thousands of users, handling massive amounts of input, output and storage.

• Mainframe computers are used in large organizations where many users need access to shared data and programs.

• Mainframes are also used as e-commerce servers, handling transactions over the Internet.

Minicomputers: are smaller than mainframe, general purpose computers, and give computing power without adding the prohibitive expenses associated with larger systems. It is generally easier to use.

• Minicomputers usually have multiple terminals.

• Minicomputers may be used as network servers and Internet servers.

Workstations

• Workstations are powerful single-user computers.

• Workstations are used for tasks that require a great deal of number-crunching power, such as product design and computer animation.

• Workstations are often used as network and Internet servers.

Microcomputers, or Personal Computers : is the smallest, least expensive of all the computers. Micro computers have smallest memory and less power, are physically smaller and permit fewer peripherals to be attached.

• Microcomputers are more commonly known as personal   computers. The term “PC” is applied to IBM-PCs or compatible computers.

• Desktop computers are the most common type of  PC.

• Notebook (laptop) computers are used by people who need the power of a desktop system, but also portability.

• Handheld PCs (such as PDAs) lack the power of a desktop or notebook PC, but offer features for users who need limited functions and small size.

Personal Computers(PC)

Desk Top

Lap Top

Palm Top

PDA

According to Technology

• Analog Computers

•  Digital Computers

•  Hydride Computers

Analog Computers:- These computers recognize data as a continuous measurement of a physical property ( voltage, pressure, speed and temperature).

 Example: Automobile speedometer

Digital Computers:- These are high speed programmable electronic devices that perform mathematical calculations, compare values and store results. They recognize data by counting discrete signal representing either a high or low voltage state of electricity.

Hybrid Computers:-A computer that processes both analog and digital data.

According to Purpose

1. General purpose Computers
2.  Special Computers

General purpose Computers

A ‘General Purpose Computer’ is a machine that is capable of carrying out some general data processing under program control.

Refers to computers that follow instructions, thus virtually all computers from micro to mainframe are general purpose. Even computers in toys, games and single-function devices follow instructions in their built-in program.

Special purpose Computers

A computer that is designed to operate on a restricted class of problems.

Use special purpose computer equipment to obtain patient diagnostic information.

computer history

 Lab Work 2(Computer history & generations)

Computer History

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem. An important class of computer operations on some computing platforms is the accepting of input from human operators and the output of results formatted for human consumption. The interface between the computer and the human operator is known as the user interface.The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations.

Generations 

First generations - 1940-1956(vacuum tubes)

• very expensive
• need big space
• only could solve one problem at a time
• relied on machine language

Second generations - 1956-1963(transistors)

• made computer more faster,cheaper.
• high level programming language
• save more energy

Third generations - 1964-1971(integrated circuits)

• increased speed and efficiency.
• can run many program at one time
• small and cheaper

Fourth generations - 1971-Present(microprosessors)

• can fit in palm hand
• more powerful
• can link to make network

Fifth generations - Present and Beyond(artificial intelligence)

develop devices that respond to natural language input

• capable of learning
• self organizations