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Output Devices:Sends Processed Data out of the computer.

– Monitors– Printers

• Output devices make:– Soft copies (video, sounds, control signals)– Hard copies (print)

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2- Output Devices

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Monitor TypesCRT (Cathode-Ray Tube):

– Less expensive– Uses much more space– Uses more energy– Offers better viewing

angles– Legacy technology

LCD (Liquid Crystal Display)– More expensive– Uses far less space– More energy efficient– Less viewable from an angle

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Printers

Impact printers

• Have tiny hammer-like keys that strike the paper through an inked ribbon

• Legacy technology.

• Dot-matrix.

Nonimpact printers

• Spray ink or use laser beams to transfer marks onto the paper.

• Inkjet• Laser

Specialty printers

• Multifunction(all in one)

• Plotters• Thermal printers

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Nonimpact Printers1- Inkjet

– Less expensive device– Print high-quality color

images cost effectively– Popular

2- Laser– More expensive device– Faster printing speed– Less expensive per page in

B&W– Color lasers are becoming

less expensive

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Wireless Printers

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Wireless printers types :

Wi-fi:Sends data more

quickly than BluetoothBluetooth

Choosing a Printer

1. Speed (ppm):pages it can print per minute (ppm).

2. Resolution (dpi):measured in dots per inch (dpi).

3. Color output4. Memory5. Use and cost6. Cost of consumables

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Specialty printer3. All-in-one peripherals

– Scanner, copier, printer and fax

– Inkjet or Laser printer

4. Photo printers: - print digital images.

5. Plotters– Large printers.– Print oversize images,

maps and architectural plans.

6. Thermal printer :- Color generated by

melting wax or by burning dots onto specially coated paper

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Other Video Output

• Touch-screen monitors– Double as both input and output devices

• Projectors – Project a computer image to a large screen for

sharing with large groups

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Outputting Sound

• Speakers and headphones

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Inside the System Unit• A system unit is a box that contains the central electronic • Essential electronic components used to process data

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The Motherboard

The Motherboard: is the main circuit board that contains the

essential processing parts. Components of the motherboard:1. CPU2. Memory3. Expansion cards and slots

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The Motherboard

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1. Central Processing Unit (CPU)• Referred to as the “brain” of the computer• Controls all functions of the computer• Processes all commands and instructions• Can perform billions of tasks per second• Processor Speed is measured in units of Hertz (Hz) “machine cycles per

second”

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Memory

Random Access Memory (RAM)

– Stores instructions and data

– Temporary (volatile) storage.

– Consists of several memory cards or modules

Read-Only Memory (ROM)

– Stores start-up instructions

– Permanent storage

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

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Expansion Cards

• Add functions• Provide new connections for peripheral devices• Common types:

– Sound Card– Video Card (VGA)– Modem Card => Internet Connection– Network Interface Card (NIC) => to connect with

other computers.

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2- Power Controls

1- Power-on button: Turns on system, should not be used to turn it off

2- Sleep Mode:All the documents, applications, and data you were using

are stored in RAM, to quickly access it when restarting your computer.3- Hibernation:

Stores your data in memory and saves it to your computer's hard disk.

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3- Storage DevicesDrive Bays

• Drive Bay: special location reserved for storage devices.

1- Internal drive bays:– Cannot be access from outside the system– Are reserved for internal hard drives

2- External drive bays:– Can be accessed from outside the system– CD or DVD drives– Floppy and zip drives

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Storage Devices

Magnetic Storage

Devices

Hard Disk Floppy Disk

Optical Storage Devices

CD DVD BD

Solid State Devices

Flash Memory SD-Card Memory Card

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Storage Media Capabilities

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Connecting Peripherals to the Computer

• Ports:- places on the system unit where peripheral devices attach to the computer.

- data can be exchanged between devices and the operating system.• Types of ports:

– Serial:• Sends 1 bit of Data at a time -> Modems

– Parallel:• Sends groups of data bits between devices -> Printers

– Universal Serial Bus (USB):• High Speed of Data transfer.

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– FireWire:• Speedy Data Transfer -> Hard Disk, Digital Camera...etc.

– Connectivity:• Gives Access to Network & Internet.

– Ethernet:» Provide Speed Up to 1000 MBPS

– Modem:» Uses Traditional Phone Line

- Multimedia:• Video Graphics Array (AVG)• Digital Video Interface (DVI)• Super Video (S-Video)• High Definition Multimedia Interface (HDMI)

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S-Video

Computer Ports

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Setting It All Up: Ergonomics

• Ergonomics: - minimizing injury or discomfort while using the

computer• Steps to follow:

– Position monitor correctly– Use adjustable chair– Assume proper position while typing– Take breaks– Ensure adequate lighting

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Using proper equipment that is adjusted correctly helps prevent repetitive strain injuries while working at a computer.

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Chapter Summary1. What exactly is a computer, and what are its four main

functions? 2. What is the difference between data and information? 3. What are bits and bytes, and how are they measured? 4. What devices do I use to get data into the computer? 5. What devices do I use to get information out of the computer? 6. What’s on the motherboard? 7. Where are information and programs stored? 8. How are devices connected to the computer? 9. How do I set up my computer to avoid strain and injury?

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