Types of Computer SystemsT. VinothrajLecturer in Computer ScienceEastern University Sri Lanka

2 1. Classification based on operational principle Analog Computer  Digital Computer Hybrid Computers

3 Classification based on operational principle Analog Computer 

Analog computers are the first computers being developed An analog computer is a form of computer that

uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved

Analog computers are used to process analog data. Analog data is of continuous nature and which is not discrete or separate.

Analog computers are widely used for certain specialized engineering and scientific applications, for calculation and measurement of analog quantities.

The analog computer has become obsolete type of computer these days.

4 Classification based on operational principle Digital Computer

A computer that performs calculations and logical operations with quantities represented as digits, usually in the binary number system

Hybrid Computers A combination of computers those are capable of

inputting and outputting in both digital and analog signals. A hybrid computer system setup offers a cost effective method of performing complex simulations.

5 2. Classification based on Computer sizes and power Computers can be generally classified by size and

power as follows (though there is considerable overlap) Personal computer Workstation Minicomputer Mainframe Supercomputer

6 Supercomputer

An extremely fast computer that can perform hundreds of millions of instructions per second.

Very expensive Employed for specialized applications that require

immense amounts of mathematical calculations For example

weather forecasting scientific simulations, nuclear energy research fluid dynamic calculations, analysis of geological data

7 Supercomputer

Example: TitanThe fastest supercomputer in the world is used to study alternative energy resources and climate change simulations in a global level.

8 Mainframe

A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.

A very large and expensive computer In some ways, mainframes are more powerful than

supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe.

9 Mainframe

10 Minicomputer

Mini computers like the mainframe computers are used by business organization. 

A multi-user computer capable of supporting up to hundreds of users simultaneously.

a midsize computer

11  Workstation

A workstation is like a personal computer, but it has a more powerful microprocessor and, in general, a higher-quality monitor.

A powerful, single-user computer Used for engineering applications (CAD/CAM),

desktop publishing, software development The most common operating systems for

workstations are UNIX and Windows NT. workstations are typically linked together to form a

local-area network, although they can also be used as stand-alone systems.

12 Server

A computer that has been optimized to provide services to other computers over a network. Servers usually have powerful processors, lots of memory and large hard drives. The next type of computer can fill an entire room.

13Embedded system

An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints.

It is embedded as part of a complete device often including hardware and mechanical parts. Embedded systems control many devices in common use today.

14 Microcomputer/Personal Computers A small, single-user computer based on a

microprocessor A small, relatively inexpensive computer designed

for an individual user Used for word processing, accounting, desktop

publishing, and for running spreadsheet and database management applications.

15 Personal Computer Types

PCs: Two basic flavors of chassis designs Desktop models and Tower models

16 Personal Computer Types

Laptops Also called notebooks Laptops are portable computers that integrate

the display, keyboard, a pointing device or trackball, processor, memory and hard drive all in a battery-operated package

17 Personal Computer Types

Netbook – This is similar to a laptop, the only difference being that it is smaller in size, which makes it even more portable. It is also less expensive and performs the basic functions, but its internal parts are not as powerful as a desktop or laptop.

18 Personal Computer Types

Tablet computers A tablet computer is a mobile, quite thin device, having

a flat surface. The device can be easily held in your hand.

It contains a touch screen which is operated using your fingers in various ways such as tapping, double tapping, swiping and pinching.

19 Personal Computer Types

Smartphones These are true multifunctional devices. Quite recently

the mobile phone has developed into what is now called a 'smartphone'.

20 Personal Computer Types

Wearable Computer The latest trend in computing is wearable computers.

Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, visors and even clothing.

21 3. Classification based on the Purpose According to purpose, computers are either general

purpose or specific purpose. General purpose computers are designed to

perform a range of tasks. They have the ability to store numerous programs, but lack in speed and efficiency.

Special purpose computers are designed to handle a specific problem or to perform a specific task. A set of instructions is built into the machine. often attached to sensors to measure and/or control

the physical environment E.g.: The processor used to control an Aeroplane,

missile

22 Types of Computers- Summary

Analog computers

Purpose wise

Digital computers

SpecialPurpose

GeneralPurpose

Computers

Micro Computers

ServerComputers

WorkstationComputer

MiniComputer

MainFrame

Hybrid computers

Size & performance wise

SuperComputer

Thanks!23