Chapter 1 1

 The computer system consists of: 1. Hardware: Physical Components, like the system unit,monitor,keyboard, mouse, camera, printer … etc. 2.Software: set of instructions that tell the computer what to do and how to do it. 2

 Computers vary in performance and cost, in size and capabilities  Therefore, there are many types of computers that are used for different purposes. 3

 The most popular, and not very expensive.  The software that is compatible with the PC depends on the manufacturer of this PC. 4

- There are two kinds of PC’s : 1) IBM Compatible computers (Windows) 2)Apple computers (Macs OS) 5

 Portable and Briefcase sized  As powerful as a PC but more expensive 6

 Portable Hand-held computers.  Does very simple functions, and relatively cheap.  Also called “ Notepad ”. 7

 PDA(Personal Digital Assistant): Small pen controlled, handheld computers Used to send and receive faxes and s, play games, Calender  Mobile Phone: electronic telecommunication Device (SMS, MMS) 8

 Smart phone: Mobile phone with a PC-like functionality. ( , Internet, Camera, Play music, read document)  Multimedia Player: Allows you to store digital music/video. Ex. iPod 9

1) CPU(processor) 2) Memory 3) Storage Units 4) Input Devices 5) Output Devices 10

- It performs all calculations and determines how fast your computer will run. - CPU speed is measured by MHZ/GHZ. 11

- CPU elements: -Control Unit (CU): responsible for controlling the sequencing and timing of the other elements making up the CPU. -Arithmetic Logical Unit (ALU): performs arithmetic and logical operations. -Registers: -Buses: collection of wires 12

 The part of the computer where data and programs are stored temporarily. 1) Random Access Memory (RAM) 2) Read Only Memory (ROM -Booting Up) 3) BIOS 4) Cache memory 5) Video memory 13

RAM Electronic memory that temporarily stores information inside a computer This memory is volatile, If you do not save the data to the ROM, it will disappear when you turn off the computer 14

 This memory does not lose information, even when the power is turned off  Once data is programmed into the ROM chip, its contents cannot be altered. 15

 Store data recently used by the CPU.  Very fast chips, so that to reduce the speed gap between CPU and RAM. 16

 A port : is a socket on the outside of the system unit that is connected to an expansion board in the inside of the system unit. 1) USB Port 2) Serial Port 3) Parallel Port 4) Network Port 5) Fire Wire 17

 Computer’s performance: the factors that affect the speed of the CPU processing. 1) RAM 2) Hard Disk speed 3) Hard Disk space 4) Defragmenting Files 5) CPU speed 6) Number of running applications 18

 Computers store information in the form of BITS and BYTES.  A BIT is either a 0 or a 1.  Grouping 8 BITS, produces a 1 Byte, which represents the memory unit.  Memory capacity is measures by the number of bytes it can hold. 19

 Data in the computer is represented using the Binary System which has only two digits 0 or 1.  Decimal System has 10 digits (0-9)  Example :  Decimal Binary 

Memory unitNumber of Bytes Binary Representation Byte1 Byte(8 BITS)2 0 Byte Kilo Byte1024 Bytes2 10 Bytes Mega Byte Bytes2 20 Bytes Giga Byte Bytes2 30 Bytes 21

Bit Byte KB GB MB TB TB = 1024 GB GB =1024 MB MB = 1024 KB KB = 1024 Byte Byte = 8 Bits Largest Unit Smallest Unit Example : 1 TB = 1024 x 1024 = 2 20 MB GB= 1024 x 1024 x 1024= 2 30 BYTE KB = 1024 x 8= 2 13 Bits 2 10 =1024

 Devices that save the result of the processed data permanently for later retrieval. Examples 1. Internal Hard disk 2. External Hard disk 3. Floppy Disk 23

4. CD-ROM (CD-R, CD-RW) 5. DVD 6. USB Flash Drive 24

7. Network Drive 8. Online File Storage 9. Memory Card 25

Devices that allow the user to enter data into the computer 1. Keyboard 2. Mouse 3. Trackball 4. Touchpad 26

5. Scanners 6. Joystick 7. Microphone 8. Digital Camera 9. Web Camera 27

Devices that translate information after being processed into a form the user can understand. 1. Monitors a. Traditional computer monitors. b. Flat –Panel Display. 2. Projectors 28

3. Speakers. 4. Speech Synthesizer. 29

5. Printers a. Laser Printers. b. Inkjet. c. Dot Matrix. 30

Touch Screen 31