361 Hardware, Software, and Computer Performance Lec 2

Lecture Topics 1)What is a computer ? 2)Types of Computer. 3)Hardware. 4)Software. 5)Networks. 6)Computer Performance. 2

What is a computer ? A computer is a machine that takes in data and instructions (input), works with the data (processing), gives the processed information back to the user (output). The computer uses a series of 0s and 1s to describe data and to represent information. 3

Parts of the computer Desktop computer System 4

Types of Computer 5 1)Mainframes: These are the largest and most powerful of computers. The biggest of these are sometimes called Supercomputers. Cost: Mainframes are also the most expensive machines in terms of both initial cost and maintenance. A mainframe can cost millions. Mainframe computer

Types of Computer 6 2) Network computer Network computers are also sometimes known as thin clients or dumb terminals. Network computers provide remote access to a mainframe. Cost: Network computers are relatively simple devices, hence they are fairly cheap.

Types of Computer 7 3) Personal computers Personal computers or PCs for short are the type of computer that most users are familiar with. Because they are usually found on users desks, they are also sometimes called desktop computers. Cost The cost of a personal computer is greater than that of a network computer or PDA but less than that of a laptop and a very small fraction of the price of a mainframe.

Types of Computer 8 4) Laptop Laptops or Notebooks are similar to personal computers except that they comprise an integrated unit. Cost : More expensive than personal computers.

Types of Computer 9 5) PDA / Personal Digital Assistant: The PDA is the smallest of all computers. Their main task is to maintain a diary and keep contact lists. Most PDAs are able to connect to a personal computer so that data can be exchanged. Cost: Usually a PDA is less expensive than a personal computer.

Computer system 10 A computer system is made up of : 1. Hardware - The physical components. 2.Software – The programs or lists of instructions.

Hardware A hardware is physical parts of the computer you can actually touch. The hardware for a computer system consists of: 1. Input devices. 2. System unit. 3. Output devices. 4. Secondary storage devices. 11

1. Input Devices Input devises are hardware components that convert data from an external source into electronic signals understood by the computer. Types of output devices: Key Board Scanner Microphone Digital Camera Barcode Reader Mouse 12

2. System Unit 13 The system unit

Main system unit components: Motherboard: – It contains slots for the processor chip, memory slots, and slots for adapter cards for video, sound, and connection to peripheral devices. 2. Processor chip (CPU): – The Central Processing Unit (CPU) is the portion of a computer system that carries out the instructions of a computer programs. It acts as the BRAIN OF COMPUTER.

Main system unit components: 3. Memory: – Memory is a form of semiconductor storage that resides insides the computer on a motherboard. It stores operating system commands, programs and data. Main types of Memory : 1. ROM (Read Only Memory) permanent memory that has been burned on the chip at the factory. 2. RAM ( Random Access Memory) stores data that the computer needs to use temporarily. 15

Main system unit components: Hard drive or Hard disk – The hard drive is the data center of the computer where the software is installed, and where your documents and other files are stored. – The hard drive is used to stores data permanently. 5. CD/DVD ROM – Often called CD-ROM or DVD-ROM drive, these let your computer (read /write ) CDs or DVDs.

Main system unit components: Power supply – A power supply box convert the power available at the wall socket to the power necessary to run the computer.

3.Output Devices Devices that allow a computer to give information to the user. Types of Output devices: Printer Headsets Data Projector Speakers Monitor 18

4. Secondary storage devices 19 The computer has both primary and secondary storage spaces. 1) Primary storage devices – Memory. 2) Secondary storage devices :

Secondary storage devices Secondary storage devices 20 2) Secondary storage devices as: CD/DVD Floppy disk SD Card Internal hard drive. External hard drive. Hard disk

Software Software programs consist of step-by-step instructions that direct the computer hardware to perform specific tasks such as multiplying, dividing or delivering data. The three major categories of software are: 1.Operating System (OS). 2.Languages. 3.Applications. 21

Networks 22 A set of computers connected together so that they can communicate is called a computer network. This involves installing network cards in each computer. Each computer is then connected through cabling to a central device called a hub. The most commonly used protocol for establishing and maintaining communication across a network is called TCP/IP or Transmission Control Protocol / Internet Protocol.

Types of networks 1. LAN A LAN or Local Area Network is a group of computers within the same building, or within a group of buildings that are in close proximity, that are connected together. 2. WAN A WAN or Wide Area Network is a group of widely dispersed computers that are connected together. These could be across the same town, or across a country or even across the world. 3. Internet Many WAN connected together around the globe to give us the Internet that we use today. 23

Computer Performance 24 The performance of a computer is determined by a number of factors, all of which work together. 1. CPU: The model of the CPU and its speed are the first factors that determine computer performance.

Computer Performance RAM: If a computer does not have sufficient RAM, it has to make use of the hard disk to store intermediate data that it would normally store in RAM, this will slow down the computer.

Computer Performance Number of applications The more open applications and documents will place a burden on the processing power of the computer. For best performance, only open the applications and documents you need.

Computer Performance Graphics cards: The graphics card is the unit that converts the signals from the CPU into a form that can be displayed on the monitor.

Questions ??? 28

Thank you  29