Cyberwalker :: Print an Article

Cyberwalker.com

Tech help that's really helpful!

What's connected to a computer? All about peripherals

Created: 14 Dec 2001 ::: Last updated: 02 Jun 2007
Applies to: _ Win95 _ Win98 _ WinMe _ Win 2000/NT _ WinXP _ WinVista _ MacOS

By Andy Walker

Let's go over what you'll see outside your computer. These are known as "peripherals" and are normally connect by cables.

Display

This is the television-like screen where the results of a computer's tasks are displayed. Displays (or monitors) come in all sizes, but most commonly they are either 15 or 17 inches (measured diagonally from one corner of the screen to the opposite corner). The monitors with bulbous back ends are sometimes called CRTs, which is short for Cathode Ray Tube. This refers to the technology inside the monitor. Some newer monitors are flat. These are called flat-panel or TFT (thin film transfer) displays.

Mouse

A mouse is a device that is used to control the computer. It is normally a teardrop shaped gadget with buttons at one end. A cable connects the mouse to a computer. When the mouse is moved on a pad, called a mousepad, the cursor on the screen moves. A cursor is a small symbol displayed on the computer screen (normally a diagonal arrow that is used as a pointer) that shows you what the mouse is referencing on the screen. When a computer performs specialty tasks, the cursor changes into a different symbol to represent that a computer program is in a special mode. For example, when you are editing text, the cursor is a vertical line that shows where you are in the text.

Keyboard

A computer keyboard contains all the letters of the alphabet and numbers one through nine. It operates like a typewriter keypad, but instead of moving an arm, which strikes the paper, it sends an electronic impulse to the computer, which displays a character on the monitor.

Floppy Drive

A floppy drive is a part of the computer that can read and record onto a special disk, referred to as a "floppy disk". The actually drive is a little bigger than half a piece of bread, but you will only see it as a slit in the front of the computer. This slit is where the floppy disk is inserted. The actual "floppy disk" is inside a 3.5-inch square plastic covering. Floppy disks, which are magnetic, can contain about 1.44 megabytes of data, which is enough space for perhaps all the works of Shakespeare, but in the computer world this is not very large. It is used to store information outside the computer or to move data files between computers.

CD-ROM Drive

A CD-ROM is a computer drive that reads Compact Disks similar to the ones you can play on a stereo. CD-ROM means "Compact Disk - Read Only Memory". A CD-ROM drive can read either audio Compact Disks (CDs) or data Compact Disks. Data Compact Disks can contain computer programs and data. This information is recorded as tiny pits on the surface of the CD. A laser is used to read these pits and converts these into ones and zeros (binary information), which is used by the computer. Normally when you buy a program from a computer store, it comes on a CD.

Printer

A printer is designed to output information from a computer onto a piece of paper. There are three kinds of printers: dot matrix, laser, and inkjet.

Dot-matrix printers put ink on paper by hammering tiny pins against an ink ribbon. These are rarely used any more, though sometimes you'll still see them in banks, printing information on long rolls of paper. They are also good for printing on forms.
A laser printer uses a laser beam to change the electrical charge on a cylinder called a "drum". The drum is then rolled through a powder (called "toner"). It picks up toner on the charged portions of the drum (kind of like the way static electricity can make dog hair cling to clothes). The drum then transfers the toner to paper using heat and pressure. Laser printers can print black or colour pages, though the colour ones are expensive.
An inkjet is the most inexpensive type of printer you can buy. It can create colour or black output. It works by super heating liquid ink and forcing it through tiny holes. This results in tiny ink droplets being sprayed onto the paper to create an image.

Scanner

A scanner is a device used to copy an image off paper and convert it into a digital image, which can be saved as a computer file and stored on a hard drive. Scanners can use a special kind of technology called Optical Character Recognition (OCR) available in some computer programs to read text from paper and save it as an editable document file.