Lec.2: Computer HardwareLec.2: Computer Hardware Foundation year 1 Lecturer: Fatma El-Zahraa Mohamed Year: 2015/2016

A computer is a machine that takes in data and instructions as (input), works with the data as (processing), gives the processed information back to the user as (output). A computer is a machine that takes in data and instructions as (input), works with the data as (processing), gives the processed information back to the user as (output). The computer uses a series of 0s and 1s to describe data and to represent information. The computer uses a series of 0s and 1s to describe data and to represent information. What is a computer ? 2

Desktop computer System 3 Parts of the computer

Mainframe computer Types of Computer 4

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 5

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 6

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 7

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. Types of Computer 8

Computer system 9

HardwareHardware 10

Key Board Scanner Microphone Digital Camera Barcode Reader Mouse 11

2. System Unit The system unit 12

1. 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: 13

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 Memory types: 1. ROM (Read Only Memory) is 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. Main system unit components: 14

4. 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: 15

6. Power supply – A power supply box convert the power available at the wall socket to the power necessary to run the computer. Main system unit components: 16

Printer Headsets Data Projector Speakers Monitor 17 3.Output Devices

The computer has both primary and secondary storage spaces. 1) Primary storage devices – Memory. 2) Secondary storage devices : 4. Secondary storage devices 18

2) Secondary storage devices as: CD/DVD USB Floppy disk SD Card Secondary storage devices Secondary storage devices Internal hard drive. External hard drive. Hard disk 19

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 20

2. 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 21

3. 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 22

4. 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. Computer Performance 23

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