Chapter 2: Looking at Computers
Understanding the Parts of Your Computer
• Computers are data processing devices that can gather data, process data, output data, and
Data Vs. Information
• Data is a fact, figure, or idea. Example: a word, a picture, a sound, a number.
• Information is data that has been organized into a meaningful way. Example: a name and a phone
number in a directory.
• Computers will process collected data into information.
Bits and Bytes: The Language of Computers
• Computers work with numbers, a language they understand called binary, a language made up of 0’s
and 1’s. Each digit is a bit. Eight bits is known as a byte.
• Each letter in the alphabet has a unique binary code.
• Bytes can be measured in kilobytes (1000), megabytes (1 million) and gigabytes (1 billion).
• Data and information is represented as bits and bytes.
Parts of the Computer
• Your computer needs hardware the parts of the computer you can physically touch.
• Your computer also needs software (computer programs). Without software, your computer is an
• An example of application software would be Microsoft Word.
• The system software or the OS (Operating System) is the set of programs that enables your
computer to function with the hardware devices and application software. The OS is like the manager of
the hardware and software.
Different Types of Computers
Notebook: portable, battery powered computers all contained in one hardshell case.
Desktop computer: a single location system composed of a monitor, tower, keyboard and mouse.
IMac computer: an allinone, single location computer.
Mainframe computer: a large and expensive machine that supports hundreds of users. Example: used in
an Insurance Company or a University to house thousands of files and execute multiple jobs at once.
Super Computer: performs complex calculations rapidly. Example: used for weather forecasting, best at
executing fewer programs more quickly. Embedded computer: a specially designed chip inside another device. Example: inside a car or an iPod.
These computers do not interact with other systems and are meant for a single purpose.
These products allow us to enter demands and data into a computer.
• a stylus pen
• printers, fax machines and scanners
• QWERTY keyboards are the most common type. However, these are sometimes considered ineffective
• The DVORAK keyboard was designed for speed, and it places the most used keys on the home center
• Notebooks have smaller, condensed keyboards which often have no numeric board and combine some
• There are also virtual laser keyboards that react on sensor, flexible keyboards and ergodex keyboards.
Efficient Keyboard Use
• Use the numeric pad for entering numbers.
• The “F” function keys each have their own task.
• The Ctrl key is used in combination with other keys to perform shortcuts.
• The Alt key offers its own shortcuts.
• Windows key brings up the Start Menu.
• Some keyboards have multimedia buttons and USB ports.
• There are arrow control keys.
• Some keyboards are equipped with wireless capabilities, which connect to your computer through radio
Mice / Pointing Devices
• Optical mouse: an internal sensor/laser sends signals to the computer and does not require a mousepad.
• Rollerball: a ball is contained in the bottom of the mouse and sends signals to the computer. A mousepad
may be required.
• Trackball: a rolling ball sits on top of the mouse and your finger is used to move it. The mouse is
stationary and does not require any wrist movement.
• Most mice now have scroll wheels to move down pages more quickly, and other buttons for fast access.
Most Notebook computers have a touchpad mouse which is touch controlled.
• • Trackpoint Device: a small nublike joystick that is controlled with a finger.
• Wireless mice: can either be battery operated, radio frequency, or bluetooth. The receiver is plugged into
• MoGo: designed for portability, and fits into a peripheral slot on the side of your Notebook. It can store
files, and has Bluetooth capabilities.
What Can the Mouse Do?
• Magnifier: enhances viewing.
• Customizable buttons.
• Web search highlight a phrase of a word, and search.
• File storage: USB memory.
• Steering wheels
• Video console controllers (XBox)
• These devices translate your actions into the computer for enhanced gameplay.
• A touch screen is a display screen that responds to the touch of your fingers, or a stylus. A tablet PC is
similar to a notebook but it has a touch screen. You can now even write with a stylus, which makes
signing for packages easier.
• Cameras, cell phones, and camcorders connect with a data cable or wirelessly with a Bluetooth
• A webcam is a camera that can be built into your monitor, or mounted on top. They are used for video
calling and still images.
• You can equip your computer with a microphone to capture sound waves and transfer them into digital
files. They come in unidirectional (1 direction), omnidirectional (more than 1 voice in different directions),
clipon and closetalk microphones.
For Those With Disabilities
There are keyboards with extra large keys and touch screens for the visually impaired.
• • You can use a headmounted pointing device if you have limited mobility.
• Trackball mice and joysticks can be mounted directly onto a wheelchair.
These devices enable you to send processed data out of your computer in the form of text, pictures,
sounds and videos.
• monitor (displays images)
Monitor screens are made up of pixels which form together to create images. There are 3 subpixels: red,
blue, and green. Electric currents pass through the liquid crystal solution, generating light waves, which
then creates images on the screen.
• CRT’s (Cathode Ray Tube) technology that is becoming obsolete.
• LCD’s (Liquid Crystal Display) a flat panel monitor that is smaller, brighter, refreshes faster, uses less
energy, emits less radiation, and is environmentally friendly.
How Can You Ensure Quality Viewing?
• Viewing angle
• Setting the contrast ratio
• Adjusting the brightness
• Response time of the monitor
Bigger is not always better: HD screens require at least a 1920 x 1080 resolution, which can allow you to
see more on the screen.
• Some monitors have built in speakers, webcams, microphones, builtin card readers, and extra USB
Projectors also throw images onto a wall or screen. They are made quite lightweight and portable now.
• Impact printers: hammering keys that strikes the paper and leave marks.
• Nonimpact printers: spray ink, or use laser beams to transfer marks to the paper. This type has nearly
replaced impact printers because they are less expensive, quieter, faster, and produce better quality
images. • Inkjet printers: they work similarly to nonimpact printers. They’re affordable, quality, and quiet. However,
you need to purchase highquality ink and paper to produce good results.
Laser printer: fast, highquality printers created for offices and classrooms. Beams and static electricity
are used to deliver toner. Heat is then used to fuse the toner to the page. These printers have a high
• Many printers made now are wireless, allowing several people to print from different machines at once.
They are WiFi or Bluetooth equipped. Printing can be achieved from up to 30