Introduction;
Computer systems were easily classified into-Personal computers, minis, microcomputers, mainframe computers and supercomputers by considering their size, performance and cost. Today, classifying
computers on these bases is difficult due to the ever increasing pace of change of technology. However of computers still come in a variety of sizes and with a variety of processing capabilities.
- Personal Computers (PCs)
PCs are generally single-user machines with multi-tasking capabilities. PCs were first known as microcomputers because they were a complete computer but built on a smaller scale compared to the huge computer systems in use at the time. Modern PCs are more powerful and can carry out millions of instructions per second.
- They are useful for lots of different types of tasks including; Running application software such as word processors, spreadsheets and database management systems.
- Designing of super structures in Computer Aided Design (CAD)
- Desktop PCs.
They are usually small enough to fit-on a desk top. The desktop PC has a central processing unit housed in a metal or plastic case. A keyboard and mouse are usually used to input data and a monitor to output the data.
They are either used as stand-alone machines or connected in a network
- Work Station
A work station is a desktop computer that has a more powerful processor, additional memory and enhanced capabilities for performing a special task such as 3D graphics, games development, etc.
- Tablet PCs
'A tablet pC is a pen-based computer that provides the screen capabilities of a PDA with the flectional capabilities of a notebook or desktop computer.
Tablet PCs allow one to use a stylus (pen-like tip) to write notes on
the screen. You can touch the screen to perform functions. ipad is an
example of a tablet PC designed and developed by Apple company.
Slate tablet PCs are very thin and have their storage devices, CPU, and RAM integrated beneath their screen.
- Laptop and Notebook
These are small portable and fully functional battery powered PCs designed to be carried around. Portable PCs such as notebooks, laptops, tablets, smart phones etc, are in high demands these days because:
- Changes in working/living patterns: Many people need to be able to move about during their working day and still stay glued to their computer.
- Growth of wireless networking: With wireless network technology people can move around and still use their laptops to stay connected to the home or once network in order to access files and data.
- Improvements in battery life: The batteries in early laptops didn't last for much longer periods of time.
- Reduced size and weight: Modern laptops are now fairly compact reasonably light to carry compared to early laptops.
- supercomputer
Supercomputers are the fastest and most expensive computers in the world. They perform highly sophisticated or complex scientific calculations needing massive processing power
They are most often used in scientific and military weapons research, space exploration, weather modelling and analysis, drug research, oil exploration, aircraft design, etc.
Supercomputers generate much heat while working. Many are kept in rooms with air conditioning systems. Special filters are used to keep the air clean.
- Mainframe computer
In the early days of computing, huge computers that could fill an
entire room were referred to as mainframe. Mainframe computers are large, powerful computers that are capable of carrying out many different tasks for many different people at the same time.
