Here, we want to concentrate on the external hardware parts of the computer system, their types, functions and how they can be used. A proper understanding of this subject matter as far as computer is concerned will help beginners immensely on how best they can use these devices.
The hardware are the parts of a computer itself including the Central Processing Unit (CPU) and related microchips and micro-circuitry, keyboards, monitors, case and drives (floppy, hard, CD, DVD, optical, tape, etc…). Other extra parts called peripheral components or devices include mouse, printers, modems, scanners, digital cameras and cards (sound, colour, video) etc… Together they are often referred to as a personal computers or PCs.
The monitor is one of the output devices that shows information on the screen when you type. Without the monitor, you cannot see what is going on in the computer. This is called outputting information. When the computer needs more information it will display a message on the screen, usually through a dialog box. Monitors come in many types and sizes from the simple monochrome (black and white) screen to full colour screens.
Most desktop computers use a monitor with a cathode tube and most notebooks or portable systems use a liquid crystal display (LCD) monitor. To get the full benefit of today’s software with full colour graphics and animation, computers need a color monitor with a display or graphics card.
The keyboard is one of the input devices used in sending information into the computer or input information. There are many different keyboard layouts and sizes with the most common for Latin based languages being the QWERTY layout (named for the first 6 keys). The Standard keyboard has 101 keys while the Enhanced keyboard has 104 keys and above.
Some of the keys have a special use. There are referred to as command or computer keys. The 5 most common are the Escape or ESC, Control or CTRL, Alternate or Alt and the Shift keys though there can be more (the Windows key for example or the Command key). Each key on a standard keyboard has one or two characters. Press the key to get the lower character and hold Shift to get the upper.
Sections in an Enhanced Keyboard:
(1) Programme functioning area (F1 – F12)
(2) Typing area or Alphanumeric area (combination of alphabets and numbers)
(3) Movement area or dedicated cursor keys (8 in number)
(4) Numeric key pad (this section of the keyboard is control by the Num Lock. That is, when the Num Lock light is on, the numbers functions but when turned off, the commands written below the numbers take charge)
(5) The Status Indicator (Indicates the Num Lock, Caps Lock and Scroll Lock Light)
(6) Computer Keys (such as Power, Sleep, Wake, Pause Break etc.)
Keyboard Layout And Data Entry:
Enter or Return – Moves the cursor down one line and to the left margin. Enter also process commands such as choosing an option in a dialog (message) boxes and submitting a form.
Del or Delete – Deletes the character at cursor and/or characters to the right of the cursor and all highlighted (or selected) text.
BKSP or Backspace – Deletes the character to the left of cursor and all hightlighted text.
Space Bar – Moves the cursor one space at a time to the right
Shift Key – Use the shift keys to type capital letters and to type the upper character on keys with two characters on them.
Caps Lock – Locks the keyboard so it types capital letters (a light goes on when caps lock is on)
Tab – Moves the cursor five spaces to the right (number of spaces are usually adjustable). Tab moves to the next field in a form or table (Shift-Tab for previous field).
ESC or Escape – Cancels a menu or dialog box
Arrow Keys – Moves the cursor around document without changing text
Function Keys or F Keys – Access commands by themselves or in combination with the three command keys; CTRL, SHIFT, and ALT
Command Or Special Keys:
Command keys normally do nothing on their own but work in combination with other keys. Each piece of software uses the command keys differently though there is a move to standardize some functions. The Control key or Ctrl is often used to access commands. The Alternative key or Alt is often used to access menus. The Shift key is used to type CAPITAL LETTERS. As well the command keys are all used to move through documents and edit text faster and easier. As well many computers have Special keys design specifically for the particular computer. Many keyboards now have a Windows key specifically for Windows 9x and newer systems.
Basic Typing Rules:
Place one space between each word, after a punctuation mark and at the end of a sentence. Always start a sentence with a capital letter. Use capitals for names, addresses, provinces and countries, places, organizations, businesses, associations, schools, colleges, universities, days of the week, months, holidays, nationalities, ethnic groups and languages.
Learning the keyboard is the first step to learning computers. Learning involves practice. It really is as simple as that. There are two kinds of typing.
The first is called Touch Typing. The Touch Typist uses the Home Keys (asdf for the left hand and jkl; for the right) and all the fingers on both hands as well as the thumbs for the Space Bar while typing. There are many commercial and public domain programs that are designed to teach this method.
This is another input device that is run using a mouse-controlled pointer. Generally if the mouse has two buttons the left one is use to select objects and text and the right one is used to access menus. If the mouse has one button (Mac for instance) it controls all the activity and a mouse with a third buttons can be used by specific software programs.
One type of mouse has a round ball under the bottom of the mouse that rolls and turns two wheels, which control the direction of the pointer on the screen. Another type of mouse uses an optical system to track the movement of the mouse.
Note: It is important to clean the mouse periodically, particularly if it becomes sluggish. A ball type mouse has a small circular panel that can be opened, allowing you to remove the ball. Lint can be removed carefully with a tooth pick or tweezers and the ball can be washed with mild detergent. A build up will accumulate on the small wheels in the mouse. Use a small instrument or finger nail to scrape it off taking care not to scratch the wheels. Track balls can be cleaned much like a mouse and touch-pad can be wiped with a clean, damp cloth. An optical mouse can accumulate material from the surface that it is in contact with which can be removed with a finger nail or small instrument.
The Mouse Operates Under Three Forms
(1) Pointing: This is an act of positioning the mouse pointer on a particular icon or location. In this case, nothing happens.
(2) Clicking: This is an act of pressing the left mouse button once or twice for double clicking in order to execute a command.
(3) Dragging: It is an act of pressing the left mouse button and moving the mouse. This action enable users to draw objects and carry them from one place to another.
Central Processing Unit (CPU):
This is the brain or the engine of the computer that controls every system manipulations. Though the term relates to a specific chip or the processor a CPU’s performance is determined by the rest of the computers circuitry and chips.
Currently the Pentium chip or processor, made by Intel, is the most common CPU though there are many other companies that produce processors for personal computers. Examples are the CPU made by Motorola and AMD. With faster processors the clock speed becomes more important.
Compared to some of the first computers which operated at below 30 megahertz (MHz) the Pentium chips began at 75 MHz in the late 1990’s. Speeds now exceed 3000+ MHz or 3 gigahertz (GHz) and different chip manufacturers use different measuring standards (check your local computer store for the latest speed). It depends on the circuit board that the chip is housed in, or the motherboard, as to whether you are able to upgrade to a faster chip. The motherboard contains the circuitry and connections that allow the various components to communicate with each other.
Though there were many computers using many different processors previous to this I call the 80286 processor the advent of home computers as these were the processors that made computers available for the average person. Using a processor before the 286 involved learning a proprietary system and software. Most new software are being developed for the newest and fastest processors so it can be difficult to use an older computer system. Those are the four major parts of the computer system which the computer cannot do without.