The document discusses different types of computer classification based on purpose, function, and size. General purpose computers can perform many different tasks while special purpose computers are designed to perform a single specific task. Based on function, computers are digital, analog, or hybrid. Classification by size includes microcomputers, minicomputers, mainframes, and supercomputers, with the latter being the most powerful and used for complex calculations.

1. Week-2 Types of Computer Classification w.r.to Purposes General vs Special Purpose Computers Classification w.r.to Function or Logic used Digital, Analog & Hybrid Computers Classification w.r.to Size Super, Mainframe, Mini & Micro-Computers

2. Classification of Computers with respect to purposes With respect to purposes, computers are divided into two types General Purpose Computers All those computers which are used for general purposes. E.g. A personal computer used for playing games, word processing, Accounting Information System, Management Information System etc These computers can store a huge amount of data. PCs are the example of General Purpose Computers. Special Purpose Computers It is also known as dedicated computers, because these are designed to perform a particular jobs. Perform a single & specific task . E.g. Computer for Games, Computer for controlling traffic lights , ATM etc These systems have predefined set of instructions permanently stored into them, that are designed to perform only one task They are fast in processing.

3. Types of computer Type of computer Digital computer Analog computer Hybrid Computer Micro Computer Main frame Computer Super Computer Mini Computer

4. Classification of Computers According to Logic Used Computers are classified into three types with respect to Function or Internal hardware structure or Logic used Digital Computer Analog Computer Hybrid Computer

5. Digital Computers Digital Computers works on discrete data. Discrete data refers to discrete values such as 0, 1. Digital computers works on 0,1(Binary Numbers) These computers based on the presence or absence of an electrical charge or binary 0 & 1. The native language of this class is therefore called binary language (Machine Language) These Systems are more accurate and precise than others Examples: - calculators, digital watches etc…

6. Analog Computer Analog Computers works on continues data. Continues data refers to those values that can not be discrete. Temperature, air pressure, speed, current, weight etc Analog computer calculates the result by measuring the continuous change in these quantities Analog computers do not require any storage capability because they measure and compare quantities in a single operation These Systems are more speedy than digital Examples: Speed meter, air pressure measurement devices, rain gauge etc. Speedometer of a car measure speed in terms of km/h or m/h, the change in temperature is measured by a thermometer in degree’s.

7. Hybrid Computer Combine the best feature of both digital and analog systems Works on both analog and digital data Speedy like analog Accuracy like digital They are used mainly in specialized applications where both analog and digital information needs processing Weather forecasting, Air Defense, Radar Controlling systems, digital petrol pumps etc. In petrol pumps, fuel flow converts into quantity and then quantity is converted into values.

8. Classification Of Computers With Respect To Size With respect to size, speed, and cost, we can classify computers in the following types: MICRO COMPTUERS MINI COMPUTERS MAINFRAME COMPUTERS SUPER COMPUTERS

9. MICRO COMPUTERS These computers are small in size. A micro computer use to have Primary memory range from a few Kilobytes to Gigabytes. They are usually designed for personal use therefore they are also called as Personal Computers (i.e. PC). These computers can easily be accommodated on the top of a desk due to their small size and hence are also called as DESKTOP computers. There is another kind of Micro Computer which can easily be placed on the lap and such computer is called as Laptops. These Laptops can be easily carried in a small briefcase. Micro Computers are highly flexible. These are also called CHIP Computers because its entire circuitry is fabricated on a single chip.

10. MICRO COMPUTERS (Cont’d) Examples:-IBM, APPLE, COMPAC, RADIO SHACK, COMMODORE, ATARI, IBM compatibles:- 286,386,486,Pentium-I,Pentium-II,Pantium-III,Pentium-IV etc… Handheld PCs (such as PDAs) lack the power of a desktop or notebook PC, but offer features for users who need limited functions and small size.

11. MICRO COMPUTERS (Cont’d) A Multi-Core Processor is a processing system composed of two or more independent cores. The cores are typically integrated onto a single integrated circuit die(known as a chip multiprocessor or CMP). Core Basic processing area of a computer processor Die A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated. A medium-scale integrated circuit die

12. MICRO COMPUTERS (Cont’d) A Dual-Core and Core 2 Duo Processor contains two cores, and a Quad-Core Processor contains four cores. A Multi-core processor implements multiprocessing in a single physical package. Cores in a multi-core device coupled together tightly. Cores may or may not share caches. Dual Core and Core 2 Duo’s are both dual core processor. Core2 duo only takes advantage because The Core 2 Duo has the same L2 cache but it has more cache size than a Dual core. However, There are architectural changes to the silicon that give the Core 2 Duo more sophisticated processing. The single- and dual-core models are single-die, whereas the quad-core models comprise two dies, each containing two cores, packaged in a multi-chip module.

13. MINI COMPUTERS These computers are smaller in size but larger as compared to Micro Computers. Less expensive Primary memory is usually in GIGA Bytes Designed for the computerization of scientific research data. Mini computer usually fills a small shelf because it includes many types of peripheral equipment attached to it. Disks are used for secondary storage Support up to hundred’s of users at a time. Examples: - PRIME-9755,VAX-8650,IBM SYSTEM-36 etc… Application :- Departmental systems (Network Servers)

14. MAINFRAME COMPUTERS These computers are very powerful. Large in size, large in memory and powerful. Mainframe computers are also capable of connecting terminals with it. These computers are used in networked environment and mainly as network servers. Mainframe computers are very expansive. They are usually designed for the computerization of huge business organizations, universities, banks, scientific laboratories, national and international markets. Multiple Input/Output devices are normally attached with a Mainframe computer. The secondary storage use to be in the form disks in a Mainframe computer. Mainframes are measured in integer operations per second or MIPS.

15. MAINFRAME COMPUTERS (Cont’d ) These computers also allow different users to work on it at the same time like Mini computers but the number of users can be much more than that of the Mini computers (upto thousand’s users can work at a time on a single Mainframe computer). Examples:- IBM-4381, IBM-360, ICL-2900,NEC-610 etc…

16. SUPER COMPUTERS Supercomputer is a computer that is at the frontline of current processing, capacity, particularly speed of calculation. Supercomputers are the most powerful computers. They are used for problems requiring complex calculations. It is not possible to consider one computer system as the most powerful, because the power of a computer is not linear. Super Computers are very difficult to design, it requires lot of research and development and at the same time they are very much expansive to manufacture. Presently approximately 30-50 Super Computers are sold per annum.

17. SUPER COMPUTERS (Cont’d ) The speed of a super computer is enormous as it was calculated at a rate of 64 billions instruction per second, like Cray T90. But now, The speed of a supercomputer is measured in " FLOPS " Such as "TFLOPS" (10 power 12 FLOPS)(1,000,000,000,000 ), or "PFLOPS" (10 power15 FLOPS,) (1,000,000,000,000,000 operation per second). Example of floating point operation is the calculation of mathematical equations in real numbers. In terms of computational ability, Supercomputers are more powerful. In February 2009, IBM designed supercomputer with 20 PFLOPS. This will be equivalent to 2 million (1,000,000) laptops (whereas Roadrunner is comparable to a mere 100,000 laptops). Cray T90 Supercomputer

18. SUPER COMPUTERS (Cont’d) Application in web services and search engines, online banking (Transaction processing), weather forecasting, Climate Prediction (50 years in 30 days by 4.8 TFLOPS) , Cryptography, Nuclear weapons (test by simulations), Earthquake and structural modeling and petroleum exploration.

19. SUPER COMPUTERS (Cont’d ) 2000, IBM ASCI White 7.226 TFLOPS DoE-Lawrence Livermore National Laboratory, California, USA 2002, NEC Earth Simulator 35.86 TFLOPS Earth Simulator Center, Yokohama, Japan 2004, IBM Blue Gene/L 70.72 TFLOPS DoE/IBM Rochester, Minnesota, USA 2005, IBM Blue Gene/L 136.8 TFLOPS DoE/U.S. National Nuclear Security Administration, Lawrence Livermore National Laboratory, California, USA 2007, IBM Blue Gene/L 478.2 TFLOPS DoE/U.S. National Nuclear Security Administration, Lawrence Livermore National Laboratory, California, USA 2008, IBM Roadrunner 1.026 PFLOPS DoE-Los Alamos National Laboratory, New Mexico, USA 2009, Cray Jaguar 1.759 PFLOPS DoE-Oak Ridge National Laboratory, Tennessee, USA