1. INTRODUCTION TO
COMPUTERS
Dr. Mostafa Mohamed Elgamala

2. Computer Types
• Six basic categories of computers
– Embedded computers (cars ,Rebots,…)
– Mobile devices (smart phones…)
– Personal computers (desktop or portable (labtop
or tablet)
– Midrange servers (small networks)
– Mainframe computers (large organizations)
– Supercomputers (one program at a time)

4. Computer Structure
1- Hardware
• Input devices
– Used to input data into the computer
• Processing devices
– Perform calculations and control computer’s
operation
– Central processing unit (CPU) and memory
• Output devices
– Present results to the user

5. • Storage devices
– Used to store data on or access data from
storage media
– Hard drives, DVD disks and drives, USB flash
drives, etc.
• Communications devices
– Allow users to communicate with others and to
electronically access information
– Modems, network adapters, etc.

6. Input
• Keyboard
• Virtual keyboard
• Touch pads
• Scroll wheels

7. – Electronic pen
– Touch screen
– Mouse
– Joysticks
– Scanner
– Barcode readers
– Radio frequency identification (RFID) Reader
– Biometric Readers
– Digital cameras
– Audio input

8. Output
• Monitor
• Plotter
• Data projector
• Audio output
• Printers

9. Motherboard

10. CPU
• Today’s CPUs contain hundreds of millions of
transistors; the number doubles about every
18 months (Moore’s Law)
• Dual-core CPU: Contain the processing
components (cores) of two separate
processors on a single CPU
• Quad-core CPU: Contains 4 cores

11. • CPU clock speed: One measurement of
processing speed
– Measured in megahertz (MHz) or gigahertz (GHz)
– Higher CPU clock speed = more instructions
processed per second
• Word size: The amount of data that a CPU
can manipulate at one time
– Typically 32 or 64 bits
• Bus: An electronic path over which data
can travel

12. Memory
• RAM ( SDRAM–DDR1-DDR2-DDR3)
• ROM

13. • Fans
• Heat sinks
• Expansion slots

14. Buses
• Bus: An electronic path within a computer
over which data travels
– System bus: Moves data back and forth between
the CPU and memory
– Expansion buses: Connect the CPU to peripheral
(typically input and output) devices
• PCI and PCI Express (PCIe) bus
• AGP bus
• Universal Serial Bus (USB)
• FireWire/IEEE 1394 (digital camera )

16. Ports and Connectors
– Serial
– Parallel
– Network
– Keyboard/Mouse
– Monitor (VGA, DVI,
HDMI)
– Modem/Phone
– USB
– FireWire
– SCSI
– MIDI ( Musical Instrument Digital Interface)
– IrDA (Infrared Data Association)
– Game

20. Storage
• Magnetic disks (HDD) (up to 4 tera)
– Parallel ATA (PATA-advanced tech. attachments)
(100 MBs)
– Serial ATA (SATA) and serial ATA II (SATA II)
(150MBs)
– SCSI and the newer serial attached SCSI (SAS)
(160MBs)
– Fibre Channel
– External hard drives
• SDD (solid state drive)(up to 500 G) (fast – low
power – long life )

23. • Optical disks
• Flash (60MBs) - Firewire(100MBs) – SD -
MMC
• SANs
• RAID
• Taps

24. Future trends
• Nanotechnology
• Quantum computing
• Optical computer

25. 2- Software
• Operating system (Windows – Unix – Linux)
• Application Software

26. QUESTIONS?