Chapter Three Computer Hardware Chapter 3- Computer Hardware

Topics Covered System Unit and Motherboard Central Processing Unit (CPU) Primary Memory Secondary Memory Input / Output Devices Expansion Cards Chapter 3 - Computer Hardware

What is Computer Hardware? Abbreviated as H/W Physical components of the computer Touchable parts maybe Electronics or Mechanical parts Chapter 3- Computer Hardware

The System Unit (Case or Chassis) The main PC box that houses the various elements: motherboard, which contains all the main components, such as the CPU and primary memory. Hard disks, the floppy disk, CD-ROM, DVD drives etc. Also contains Power Supply. System units come in two basic forms: The Tower The Desktop Chapter 3- Computer Hardware

The System Unit (Case or Chassis) Tower Desktop Chapter 3- Computer Hardware

Power Supply Chapter 3- Computer Hardware

The Motherboard Chapter 3- Computer Hardware

The System Board (Motherboard) Is the main circuit board Provides electrical connections/ communication channels to components It contains the following: CPU Primary Memory (RAM and ROM) Buses Expansion Slots (Sockets) Ports Chapter 3- Computer Hardware

Motherboard RAM Slots AGP Slot CPU Slot/ Microprocessor Pg 15 Essential Skills for Digital Literacy Motherboard Computing Fundamentals RAM Slots AGP Slot CPU Slot/ Microprocessor Expansion/PCI Slots Pg 15 Descriptions of the components labeled here are on the next slide. Input/Output Slots Chapter 3- Computer Hardware © CCI Learning Solutions Inc. Recognizing Computers – Slide 9

Central Processing Unit (CPU) The CPU is the brain of your computer It is microchip that consists of hundreds of millions of transistors It performs the following: Arithmetic/Mathematical calculations Logical Operations Chapter 3- Computer Hardware

Components of CPU Chapter 3- Computer Hardware

CPU Speed Number of basic operations executed in one second Measured in Hz (Hertz) It determines how fast your computer will run. IBM PC of 1981 runs at 4.77 MHz Present day PC runs at 2.8 GHz or faster Chapter 3- Computer Hardware

Arithmetic and Logic Unit (ALU) Also known as ALU contains the electronic circuitry that executes all arithmetic and logical operations Arithmetic Operations include Multiplication, Division, Addition, Subtraction Logic Operations include comparison like a=b, a<b, a>b, a>=b Chapter 3- Computer Hardware

Control Unit It carries out the following tasks: Reading and interpreting program instructions Directing and controlling data flow within the CPU and between the CPU and Primary Memory Note: The control unit does not execute program instructions; rather, it directs the ALU to do so. Chapter 3- Computer Hardware

Registers Registers are very high speed, immediate access storage locations where program instructions are decoded where data are temporarily stored before and after execution by the ALU Note: Registers are not part of the Main memory; rather they are special additional storage locations within the CPU. Chapter 3- Computer Hardware

Examples of CPUs Intel AMD IBM Cyrix Pentium, Celeron, Xeon Athlon, Opteron IBM Power3 Cyrix 6x86MX   Chapter 3- Computer Hardware

Measuring Memory 1 bit=1 binary (0’s and 1’s) 1 byte=8 bits 1 kilobyte=1024 bytes = (210 B) 1 megabyte=1024 kilobytes= (220 B) 1 gigabyte=1024 megabytes= (230 B) 1 terabyte=1024 gigabytes = (240 B) Chapter 3- Computer Hardware

Calculating Memory Capacity How many Bytes in 8 GB? 8 * 1024 * 1024 * 1024 or 23 * 210 * 210 * 210 = 233 How many KB in 4 GB? 4 * 1024 * 1024 or 22 * 210 * 210 = 222 How many bits in 2 TB? 2 * 1024 * 1024 * 1024 * 1024 * 8 or 21 * 210 * 210 * 210 * 210 * 23 = 244 Chapter 3- Computer Hardware

Primary Memory (Main Memory) RAM (Random Access Memory ) RAM is a volatile memory As a rule, computers with a larger RAM capacity is often faster than a computer with a smaller RAM capacity. Functions of RAM Store data and programs Store results of processing before being transmitted to the output unit Chapter 3- Computer Hardware

ROM Read Only Memory (ROM) a special type of memory chip that holds software can be read but not written to It is a non-volatile memory ROM-BIOS (Basic Input and Output System) It is the first program that is executed by CPU when the computer turned on Functions of ROM Booting Searches the OS from storage devices and loads it into RAM Chapter 3- Computer Hardware

Other Types of ROM Other types of ROM: PROM (Programmable ROM) It can be programmed using PROM programmer EPROM (Erasable PROM) Data can be erased using ultraviolet light EEPROM (Electrically EPROM) Data can be erased using electricity only Chapter 3- Computer Hardware

Cache Memory Is a high speed memory that allows the CPU to access data in a very short access time Used to store frequently used instructions or data Levels of Cash Memory: L1 on-chip (embedded in the CPU) L2 and L3 are off-chip (resides on motherboard) Chapter 3- Computer Hardware

Secondary Memory Hard Disc Drives Flash Memory Memory Cards – SD (Secure Digital) Cards CD (Compact Disc) CD-R CD-RW Can hold up to 700MB Chapter 3- Computer Hardware

Secondary Memory (con’t.) DVD (Digital Versatile Disk) Can hold 4.7GB – 17.08 GB BD (Blu-ray Disk) Can hold 25 - 50 GB Blu-ray Disk refers to the “blue-laser” used to read the disk Chapter 3- Computer Hardware

Input Device

Input Devices Keyboard (Wired, Wireless) Mouse Touch pads and Touch Screens Scanners Webcams Joysticks Barcode Readers Finger Print Readers Microphones Digital Cameras Chapter 3- Computer Hardware

Output Devices Monitor CRT (Cathode Ray Tube) LCD (Liquid Crystal Display) Plasma (Color Plasma Display) Printer Laser (Color, Black and White) Inkjet (Color, Black and White) Speakers Projectors Plotters Chapter 3- Computer Hardware

Expansion Cards an electronic board inserted into the expansion slot Examples: Modem (MODulator/DEModulator) Modulation is the Process of Converting Digital to Analogue Signal) Demodulation is the Process of Converting Analogue to Digital NIC (Network Interface Card) Video Cards Sound Card Chapter 2 - Computer Hardware

Summary What is Hardware? What is System Unit? Motherboard? What is Central Processing Unit (CPU)? What is Primary Memory? What is Secondary Memory? What are Input / Output Devices? What are Expansion Cards? Chapter 3 - Computer Hardware