Types Of ComputerPrepared By: Engr. Ahmad Sameer Nawab

Kardan University

Classification Of Computers

Computers are classified and categorized into three sort of categories according to their specific number of functionalities.

By Type

By Size

By Function

Types Of Computer Computer by size has been divided into three sub-categories which they have

various number of functionalities corresponded to them.

Hybrid Computers

Analogue Computers

Digital Computers

Analogue Computer Type Analogue types of Computer uses what is known as analogue signals that are

represented by a continuous set of varying voltages and are used in scientific research centers For example hospitals and flight centers

With analogue types of computer no values are represented by physical measurable quantities For example voltages.

Analogue computer types program arithmetic and logical operations by measuring physical changes for example temperatures or pressure.

A 1960 New mark analogue computer, made up of five units. This computer was used to solve

differential equations and is currently housed at the Cambridge Museum of Technology.

The name "Dornier" is normally linked with advanced aircraft design.

www.analoguemuseum.org

Digital Computer type With these types of computers operation are on electrical input that can attain

two inputs, states of ON=1 and state of OFF = 0. With digital type of computers data is represented by digital of 0 and 1 or off state and on state. Digital computer type recognizes data by counting discrete signal of (0 0r 1), they are high speed programmable.

they compute values and stores results.

 

Hybrid type of Computer Hybrid computer types are very unique, in the sense that they combined both

analogue and digital features and operations.

With Hybrid computers operate by using digital to analogue convertor and analogue to digital convertor.

By linking the two types of computer above you come up with this new computer type called Hybrid.

Hybrid Computer, System

hybrid computers should be distinguished from hybrid systems. The latter may be no more than a digital computer equipped with an analog-to-digital converter at the input and/or a digital-to-analog converter at the output, to convert analog signals for ordinary digital signal processing, and conversely, e.g., for driving physical control systems, such as servomechanisms.

A servomechanism, sometimes shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the performance of a mechanism.

The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position, speed or other parameters. For example, an automotive power window control is not a servomechanism, as there is no automatic feedback that controls position—the operator does this by observation. By contrast the car's cruise control uses closed loop feedback, which classifies it as a servomechanism.

Computers By Size Computer has been categorized into Four other types according to it’s size.

Microcomputers (Personal computers)

Minicomputers (Midrange computers)

Mainframe computers

Supercomputer

These four types are sub-parts of Digital Computers

Microcomputers Microcomputers are the most common type of computers used by people today, whether in a

workplace, at school or on the desk at home. The term “microcomputer” was introduced with the advent of single chip microprocessors.

The term "microcomputer" itself is now practically an anachronism.

Desktop Computers

In-car computers (“carputers”) – Built into a car, for entertainment, navigation, etc.

Game consoles – Fixed computers specialized for entertainment purposes (video games).

A separate class is that of mobile devices:

Laptops, notebook computers and Palmtop computers – Portable and all in one case.

Varying sizes, but other than smart books expected to be “full” computers without limitations.

Tablet computer – Like laptops, but with a touch-screen, sometimes entirely replacing the physical keyboard.

Smartphones, smart books and PDAs (personal digital assistants) – Small handheld computers with limited hardware.

Programmable calculator– Like small handhelds, but specialized on mathematical work.

Handheld game consoles – The same as game consoles, but small and portable.

Micro-Computers

Computermusem.li

Minicomputers A minicomputer (colloquially, mini) is a class of multi-user computers that lies

in the middle range of the computing spectrum, in between the smallest multi-user systems (mainframe computers) and the largest single-user systems (microcomputers or personal computers).

The contemporary term for this class of system is midrange computer, such as the higher-end SPARC, POWER and Itanium -based systems from Oracle Corporation, IBM and Hewlett-Packard.

E.g.- Laboratory computers

Mainframe computers The term mainframe computer was created to distinguish the

traditional, large, institutional computer intended to service multiple users from the smaller, single user machines. These computers are capable of handling and processing very large amounts of data quickly. Mainframe computers are used in large institutions such as government, banks and large corporations. They are measured in MIPS (million instructions per second) and respond to up to 100s of millions of users at a time.

Supercomputer A supercomputer is focused on performing tasks involving intense

numerical calculations such as weather forecasting, fluid dynamics, nuclear simulations, theoretical astrophysics, and complex scientific computations. A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation. The term supercomputer itself is rather fluid, and the speed of today's supercomputers tends to become typical of tomorrow's ordinary computer. Supercomputer processing speeds are measured in floating point operations per second or FLOPS.

An example of a floating point operation is the calculation of mathematical equations in real numbers. In terms of computational capability, memory size and speed, I/O technology, and topological issues such as bandwidth and latency, supercomputers are the most powerful, are very expensive, and not cost-effective just to perform batch or transaction processing. Transaction processing is handled by less powerful computers such as server computers or mainframes.

The Blue Gene/P supercomputer at Argonne National Lab runs over 250,000 processors using normal data center

air conditioning, grouped in 72 racks/cabinets connected by a high-speed optical network

Computer By Function

Computer are four types according to their functionalities.

Servers

Workstations

Information Appliances

Embedded Computers

Servers Server usually refers to a computer that is dedicated to provide a service. For

example, a computer dedicated to a database may be called a "database server“.

"File servers" manage a large collection of computer files. "Web servers" process web pages and web applications.

Many smaller servers are actually personal computers that have been dedicated to provide services for other computers.

Workstations Workstations are computers that are intended to serve one user and may

contain special hardware enhancements not found on a personal computer.

Information appliances Information appliances are computers specially designed to perform a specific

user-friendly function —such as playing music, photography, or editing text.

The term is most commonly applied to mobile devices, though there are also portable and desktop devices of this class.

Embedded computers Embedded computers are computers that are a part of a machine or device.

Embedded computers generally execute a program that is stored in non-volatile memory and is only intended to operate a specific machine or device.

Embedded computers are very common.

Embedded computers are typically required to operate continuously without being reset or rebooted, and once employed in their task the software usually cannot be modified. An automobile may contain a number of embedded computers; however, a washing machine and a DVD player would contain only one.

The central processing units (CPUs) used in embedded computers are often sufficient only for the computational requirements of the specific application and may be slower and cheaper than CPUs found in a personal computer.