Mainframe Computer

The mainframe computer is a very large computer which capable of supporting hundreds and even thousands of users at a time, as it has different terminals that can be shared simultaneously by multiple users. It is used to

. 11 An Introduction to the use of 111 LIBRARY, STUDY SKILLS & ICT

UNIVERSITY OF IBADAN LIBRARY

process large amounts of data at a very high speed; for example, it is used in banks, hospitals, airports, railway stations and by insurance companies, in fact wherever there is need to rapidly process information about millions of people. Mainframes are considered to be more powerful than super computers in some ways, because they support more simultaneous programs. It is considered to be next to the super computer in capacity 3. M in ic o m p u te r

A minicomputer is a medium, desk-sized machine used in medium scale applications. It is also known as midrange computer, and like the mainframe, it is also designed to support several users simultaneously. It also supports faster peripheral devices like printers and scanners. It possesses large storage capacities and operates at a fast speed. It is used when the volume of data to be processed is moderately large for example, processing data in a medium-sized organization. It is also used as servers in LANs (Local Area Networks), and can communicate with mainframe computers.

4. M ic r o c o m p u te r

A microcomputer is the least powerful of the computer c a te g o rie s , e s p e c ia lly w hen com p ared w ith supercomputers, mainframes and minicomputers. It uses a microprocessor as its central processing unit. A microprocessor is a silicon chip that contains a CPU embedded in it. Microprocessors control the logic of most o f the digital devices that we use today.

Microcomputers can be used by only one person at a time.

An Introduction to the use of I ■.

LIBRARY, STUDY SKILLS & IC T 1 11

UNIVERSITY OF IBADAN LIBRARY

. 11 An Introduction to the use of 111 LIBRARY, STUDY SKILLS & ICT

Common examples include chips used in TVs, washing machines, cars, clock radios, fuel injection systems for automobiles and personal computers. It is interesting to note that most of the computers that we use today are microcomputers.

The Different Models of the Microcomputer a. Personal Computers

A personal computer is designed for use by a single person. It usually supports word processing, spreadsheet calculations, database management and so on. Although it is used by individuals, it can also be used by computer networks. A personal computer comes in different forms, i.e. it can be a desktop computer, a laptop or a netbook etc.

b. Desktop Computers

A desktop computer is the most commonly used type of personal computer. It is not designed for portability, and is usually set up in a semi­

permanent location. It has a systems unit that houses most of the components used by it to perform its functions; that is, the motherboard, disk drives, the Universal Serial Bus (USB) ports, switch mode, power supply, and add-on cards.

Most modern desktops have either a tower or a flat-bed CPU which can stand either on the desk or on the floor, a flat screen monitor, of between 19-21 inches, and wired or wireless mouse and keyboards. If one of its components spoils, it can

UNIVERSITY OF IBADAN LIBRARY

be replaced without buying a new computer.

Some desktop computers employ touchscreen technology for user input.

c. W o r k sta tio n s

A workstation is a desktop computer that has a more powerful processor than the usual desktop.

It also has additional memory and enhanced capabilities for performing special tasks, e.g. 3D graphics, game development, etc.

d. S e r v e r s

A server is a desktop computer which is connected to other computers and provides services to them over a network. It usually has a powerful processor, large hard drives and lots of memory.

e. L a p to p s

A laptop, also known as a notebook, is a portable computer that combines the processor, hard drive, memory, display, keyboard and pointing device or trackball into a single, battery operated unit, slightly bigger than a hardcover notebook. It is called a laptop because it can be placed on the laps, opened and used wherever you are e.g. on a train, in the office, in class etc. A laptop is more powerful than desktops, and usually more expensive. It can work for 4-6 hours when the battery is fully charged.

f. N e tb o o k s

A netbook looks like a laptop, but is slightly smaller, with 9-10 inch screens, and very lightweight, weighing between 2-3 pounds. Its

An Introduction to the use of I ■ . LIBRARY, STUDY SKILLS & I C T 111 '

UNIVERSITY OF IBADAN LIBRARY

small size also makes it extra-portable, and this gives it an advantage over the laptop, although it has less processing power than the laptop. It is also cheaper than the laptop. It can be used in all the ways that a laptop can be used, except that it does not have a CD or DVD drive built into it like the laptop, although it has facilities whereby a separate CD or DVD drive can be connected to it externally.

g. P e r so n a l D ig ita l A s s is ta n t (P D A )

A PDA is slightly smaller than a paperback novel, very lig h tw e ig h t, and com bines voice recognition, personal organizational tools and communication capacities in a small package. It uses flash memory for storage and usually relies on either soft keys, pen or touchscreen technology for user input, and memory cards for data storage.Nearly all PDAs have the ability to connect to the Internet and connect to other computers wirelessly.

h. P a lm to p s

A palmtop is a PDA that is small enough to fit into the palm of one's hand. It is also called a hand-held computer. It is kept for personal use. e.g. for taking notes, developing a list of friends keeping track of dates, agendas, etc.

i. T a b le ts

Although a tablet may sometimes come with a detachable keyboard and a rotating screen, most of the time, it is a small flat, slate-like computer.

. 11 Ail Introduction to the use of 111 LIBRARY, STUDY SKILLS & 1CT

UNIVERSITY OF IBADAN LIBRARY

with no moving parts and with a 7-10 inch color screen, using a touch screen or pen technology for input. It can be used for all desktop and laptop functions, and is usually referred to as a Tab.

j. Mobile phones

A mobile phone is a portable electronic device used for instant communication. In recent times, mobile phones have developed into multi­

functional devices that can carry out a majority of the functions that the computer executes.

Additional mobile phone functions include short text messaging (SMS), Internet access, electronic mail or email, calculators, clocks and calendars, audio and video recording and playback, photographic display, etc.

k. Smartphones

A smartphone is basically a mobile phone that can be used for most of the functions that a computer performs. It combinesmost of the functions of phones, PDAs, cam eras, cam corders and computers in a single electronic device. To function properly, a smart phone uses operating systems, which are the basisof application development. It also has computer applications like word and spreadsheet, media player, a camera, GPS navigation, address book, diary, calendar etc. It can connect wirelessly to the Internet, and usually comes with a touchscreen or small keyboard for input.

An Introduction to the use of I ■ . LI BINARY, STUDY SKILLS & IC T 1 11 '

UNIVERSITY OF IBADAN LIBRARY

'll