Types of Computers

1. Types of Computers By Mrs. Gonzales

2. Categories of computers • These include: 1) Personal computers2) Laptops3) Minicomputers4) Mainframes 5) Supercomputers6) Tablet PC7) Electronic organizers and palmtop computers 8) Embedded computers

3. Personal Computers Personal computers (PCs), also sometimes called micro computer, are the most common type of computer. PCs are designed to be used by one person at a time and fit on an office desk, hence the other name, ‘desktop computers’. A PC consists of a system unit, a keyboard, a mouse and a display screen. It has all the functional elements found in any larger systems. It is designed to perform the input, control, arithmetic/logic, output and storage functions just like any other computer system would do. It can execute software program instructions to perform a very wide variety of tasks.

4. Laptops A laptop computer is portable version of a PC, equipped with a flat liquid crystal display (LCD) screen and weighing about 1 - 4 Kg. The two principle types of laptop computers are notebooks and sub-notebooks. Notebooks weigh 2 – 4 Kg and is roughly 35 x 25 x 4 in size. They have fairly large LCD colour screen and a fairly large keyboard, usually with a small touch-sensitive pad which serves as a mouse. They are usually just as powerful as a desktop PC but cost more than their equivalent desktop PC.

5. Laptops A sub-notebook computer weighs about ½ Kg and can fit in a large jacket pocket. It has a small screen, sometimes in colour, and a small keyboard without the mouse function. It can perform many of the functions of notebooks, but not to the same degree of complexity.

6. Minicomputers Mini systems were usually designed to handle simultaneously the processing needs of multiple users. They allowed many users to share access to central hardware through stations called terminals . Minis can support dozens of terminals. A typical terminal has a keyboard, a display screen and a wire that connects the terminal to the computer system. Minicomputers were mainly used in small manufacturing plants, research labs and businesses.

7. Mainframes Mainframes are very powerful computers and are therefore very expensive. Mainframes are systems that offer faster processing speeds and greater storage capacity than a typical mini. A mainframe can handle more than a thousand users at a time. They are found in large organizations such as banks, government agencies, insurance companies and corporations where they perform tasks that require a lot of computational power; typically, bulk data processing such as censuses, industry/consumer statistics and bank transaction processing. The IBM zSeries 990 Model D32 is currently one of the most powerful mainframe computers available.

8. Supercomputers Supercomputers such as NEC’s Earth Simulator and California Digital Corporation’s Intel Itanium2 Tiger4 were two of the largest, fastest and most powerful computers in the year 2004. They are typically used for ‘number crunching’ in scientific simulations, scientific research and developments in areas such as energy, space exploration , medicine and industry. Supercomputers are designed to process complex scientific applications. These systems are the most expensive computers in the world, often costing millions of dollars.

9. Tablet PC A tablet PC is a computer that looks like a notebook computer except that data can be entered through the use of a keyboard, touch screen or a digitizing tablet. Data can be entered through the digitizing tablet with the use of a special pen called a stylus.

10. Electronic organizers and palmtop computers These are so called because they can fit in the palm of your hand and are therefore less powerful than notebooks and sub-notebooks. They can fit into a shirt pocket and weigh perhaps 300 grams on average. They might have a very small keyboard, or a palm-sized screen (sometimes in colour) which can be written on with a special pen. Electronic organizers are mainly used to store appointments, addresses, phone numbers and ‘to do’ lists. Palmtop computers are more powerful than electronic organizers and can even run some of the same software as notebooks and sub-notebooks. Some cellular phones are now powerful enough to act as very small personal organizers.

11. Embedded computers An embedded computer is a special-purpose computer used inside a device and is usually dedicated to specific functions. It is housed on a single microprocessor board with the programs stored in ROM. It is connected to sensors – devices which detect changes in the environment such as light, temperature or pressure – and actuators, hardware output devices that convert electrical control signal into physical action. They are commonly used in items such as washing machines, cameras, cars, motors, sewing machines, clocks and microwaves.