Computer basics: Devices that can connect to a computer

Question: Most of the stuff you write about seems to be geared to intermediate or advanced computer users. How about some basic stuff for beginners? There are a lot of us out here who can use this kind of information. – Anon.

Answer: In the past, I’ve talked about what’s inside a computer. If you missed that column, please see: Computer Basics for Newcomers to Computers. This time, let’s go over what you’ll see outside your computer. These are typically known as peripherals.

MONITOR or DISPLAY – This is the television-like screen where you can see what the computer’s doing. Monitors come in all sizes, but most commonly they are either 15 to 19 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. Many newer monitors are flat. These are called flat-panel or TFT (for Thin Film Transfer) displays.

MOUSE – A computer mouse is a device used to control the computer. It is normally a teardrop-shaped gadget with buttons at one end. Most of the time, a cable connects the mouse to the computer, although you can treat yourself to a wireless mouse if you’re so inclined. 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 and zero. It operates like a typewriter keypad, but instead of moving an arm, which strikes the paper, it sends electronic impulses to the computer, which displays a character on the monitor.

FLOPPY DRIVE and FLOPPY DISK – 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 actual 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 DRIVE – Sometimes called CD-ROM, a CD drive 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 CDs or data CDs. Data CDs can contain computer programs and data. This information is recorded as tiny pits on the surface of the CD. A laser inside your computer is used to read these pits and convert them into ones and zeroes (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 anymore, but 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 economical type of printer you can buy. It can create colour or black output. It works by superheating 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 from 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 instead of a fixed image.

For more computer basics, see our article on Computer Basics for Newcomers to Computers.