1F I L L I N T H E B L A N K S O N YO U R N O T E .

COMPUTER HARDWARE

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HARDWARE

Hardware refers to the physical components of the computer system.These physical components are hard, tangible objects.

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PARTS OF THE COMPUTER

1. Monitor2. Modem3. System Unit4. Mouse5. Speaker6. Printer7. Keyboard

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THE CENTRAL PROCESSING UNIT

CPUControl

UnitArithmetic Logic Unit

Input Output

Random Access Memory (RAM)

Read Only Memory (ROM)

Main Memory

Secondary Memory (peripheral)

1. Memory stick2. CD

3. External Hard drive

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INPUT DEVICES

MouseKeyboardJoystickTouch screenOther computersScannerCameraLight pen

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OUTPUT DEVICES

• Screen • Printer• Sound

• Modem: neither input nor output. It is a communication device.

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HARDWARE NOTES

Input: A device that feeds information into the CPU

Output: It displays information from the CPU

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CENTRAL PROCESSING UNIT

This is the computer and it consists of three parts.

1. Control Unit: coordinates all processing activity (how and when to process data)

2. Arithmetic Logic Unit: performs the mathematical calculations and performs simple logic (compares 2 pieces of information and determines equality

3. Main Memory: where all the data and instructions are stored while the computer is turned on

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2 TYPES OF MAIN MEMORY

1. Read Only Memory (ROM) • Data stored here can be looked at but not changed in any

way. It is write protected. ROM often contains software programs built in by the manufacturer

2. Random Access Memory (RAM)• It is temporary storage only. When you turn your computer

of, all data in RAM is deleted. Ram is where programs that you want to use are downloaded to (including internet files). Therefore RAM plays an important part in how fast your programs will run. EG. A copy of Microsoft Word is downloaded from a secondary storage device, such as your hard drive, to RAM when you want to create a word pro document.

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SECONDARY / AUXILIARY STORAGE:

• Stores information permanently;• Acts as an input and output device• Examples:

1. Hard drive … may be external2. Memory sticks or flash drives3. Compact Disks (CD) … floppy disk???4. Cloud / Google drive / Dropbox

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TYPES OF PRINTERS

1. Dot matrix: used only in industry for printing multiple copy forms; very poor quality, slow, noisy and very inexpensive

2. Ink jet: most popular for everyday use; good quality; considerably slower than a laser printer; relatively inexpensive

Disadvantage: when one colour runs out (even is others are still full, ink cartridge must be replaced and the ink can dry up if not used regularly

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TYPES OF PRINTERS (CONT’D)

3. Plotters: a specialty printer that uses a series of ink pens to create large maps, charts, and graphs

4. Laser printers: very fast; images are precise; costs continue to drop; toner cartridges are expensive to replace

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WHAT IS A …?

1. Modem: • allows computers to exchange information using

telephone lines or cable (translator)

• It is needed for internet access, email and faxing

• What is a Router?

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WHAT IS A …? CONTINUED

2. Scanner• A device that can read images into a computer• It can scan images and text into a document that

can be edited by a program

3. Sound Card:Allows a computer to play and record high quality

soundSpeakers are required to hear the sound

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WHAT IS A …? CONTINUED

4. Port• A connection on the computer where you plug in

external devices such as the mouse or memory sticks• USB Port = Universal Serial Bus

5. Digital camera:• Takes photos and then use them on your

computer• Can place photos in documents, web-pages,

emails, etc.

16The End!