**types of computers**range from the Hybrid to the Analog types. The computers you come across in the daily course of your day range from laptops, palmtops and towers, to desktop computers, to name a few. But the very word "computers" reminds one of the desktop computers used in offices or homes. Different categories of computes have been devised in keeping with our varied needs.

**The Types Of Computers:**Analog and Hybrid (classification based on operational principle)

**Analog Computers :**The analog computer is almost an extinct type of computer these days. It is different from a digital computer in respect that it can perform numerous mathematical operations simultaneously. It is also unique in terms of operation as it utilizes continuous variables for the purpose of mathematical computation. It utilizes mechanical, hydraulic, or electrical energy or operation.**Hybrid computers :**These types of computers are, as the name suggests, a combination of both Analog and Digital computers.

Apart from this, computers are also categorized on the basis of physical structures and the purpose of their use. Based on Capacity, speed and reliability they can be divided into three categories of computers :

**The Mainframe Computer :**These are computers used by large organizations like meteorological surveys and statistical institutes for performing bulk mathematical computations. They are core computers which are used for desktop functions of over one hundred people simultaneously.**The Microcomputer :**These are the most frequently used computers better known by the name of "Personal computers". This is the type of computer meant for public use. Other than Desktop Computer the choice ranges as follows :- Personal Digital Computer
- Tablet PC
- Towers
- Work Stations
- Laptops
- Hand Held Computer

**The Mini computer :**Mini computers like the mainframe computers are used by business organization. The difference being that it can support the simultaneous working of up to 100 users and is usually maintained in business organizations for the maintenance of accounts and finances.

Today life without computers is inconceivable. Usage of different types of computers has made life both smooth and fast paced.

**Analog Computers :**

Analog Computers and Digital computers are the two kinds of computers, the combination of which is responsible for the invention of the modern Hybrid computers.

The analog systems carry out arithmetic and logical operations by manipulating and processing data which you input such as the weight, temperature, voltage, power density, etc. But unlike the digital computer that changes all inputs to binary digits of "1" and "0", the analog computer does not change inputted data to any such sign language.

The analog computer has become obsolete type of computer these days. It is different from a digital computer as it can perform numerous mathematical operations simultaneously. The digital computers, however could not operate the more complex operations. The Analog System is also unique in terms of operation as it utilizes continuous variables for the purpose of mathematical computation. It utilizes mechanical, hydraulic, or electrical energy or operation.

**Mathematical Principles Applied For The Data Processing In Analog Computers :**

- Logarithm
- Summation
- Exponentiation
- Calculus
- Multiplication and Division
- Inversion

The analog computer which is a complex machine is an integration of various mechanical parts which has pipes, valves, levers, gears and several key parts which can be named as follows :

- Fixed function generators
- Operational amplifiers
- Potentiometers
- Integrators

**Advantages and Disadvantages of Analog Computers :**

The advantage of an analog computer is that it can simultaneously find solutions to several mathematical problems and that too while being precise unlike the digital computer. But it is not free of drawbacks. Unlike the digital computer it lacks speed of calculation. There are other functional problems which mar the efficiency of analog systems. Of these, the problems of non-linearities, temperature co-efficient, parasitic effects and noise floor are the main problems so to say.

**Digital Computers :**

Digital Computers are that kind of computing machines which work on the principle of binary mathematics. Digital computing machines when clubbed with Analog computers produce Hybrid computers. The digital systems work on the principle of binary mathematics. In binary mathematics all calculations are represented through "0" and "1".

You have often heard about the word "Byte", "Mega Byte", "Kilo Byte". But what is a Byte? A single Byte is a group of 8 numbers or bits represented through a code series comprising of "0" and "1" .The combination of the digital signal can solve a number of mathematical operations. It is interesting to note that the fundamentals of mathematics applied are addition, subtraction, multiplication and division. But the chief problem is that though it can solve mathematical problems at a tremendous speed, it cannot perform bulk operations simultaneously. For this purpose, digital systems by themselves cannot give very precise results. Hence, for greater efficiency, the Digital systems do not find much application.

**Data Processing In Digital Computers :**

Digital computers function with the help of logic circuits. A reliable oscillator helps in the proper synchronization of various logic circuits that are responsible for processing data in the digital computers. In better quality computers, the oscillation rate might even be a billion cycles per second. Operating at such high speed, it can process more than billions of logic and arithmetic problems.

**Mainframe Computer :**

Mainframes are computers that are the most bulky types and with the advancement of technology, they have almost become extinct. Computers are of three types - Mainframe computers, Minicomputers and Microcomputers. Mainframe computer systems can be called the predecessor of servers because they could actually support multi users though as efficiently as the servers. Usually, a main frame would occupy an entire room and could cost over million dollars.

Used for the purpose of research, engineering works, meteorological calculations, graphics and the likes, mainframes today constitutes Unix, Linux, and IBM's z/OS, OS/390, MVS, VM, and VSE. Mainframe systems were manufactured extensively throughout the 1950s and were marketed by IBM, Control Data, General Electric, NCR, UNIVAC, Honeywell, RC, and Burroughs.

The three important Features ofmainframe Computers :

- Mainframes provide for maximum I/O connectivity as they accommodate huge disc farms.
- Mainframes excel in providing maximum I/O band width. Interestingly in spite of all the connected drives connected to the mainframe system, no data blocking ever happens to mar its efficiency.
- Mainframe systems also provide for very good single thread operations.

The Mini computers are a less bulky version of the mainframe computers. Minicomputers are used by business organization. The difference being that it can support the simultaneous working of up to 100 users and is usually maintained in business organizations for the maintenance ofaccounts and finances. Besides,there are personal computers or microcomputers. The micro computers include Desktop PC s, Laptops, Handheld computers, Tablet PC s, workstations, palmtops, etc. These are the most frequently used computers.

**Minicomputers :**

Minicomputers, what exactly are they? If supercomputers and mainframes are considered to be the best in terms of mathematical operations then minicomputer systems succeed them. Previously,minicomputers were considered to be superior to personal systems. But these days, advancement intechnology has made minicomputers almost obsolete because the PCs today are highly advanced.

The Minicomputers were first built in in 1960s and they immediately became a huge success as 40,000 of the minicomputer systems were immediately sold of making the computers hugely available to the general public. With such a successful market possibility many companies stepped in to venture in the minicomputer market. The most successful among these two hundred companies was DEC that launched the minicomputer models PDP-11 and VAX 11/780.

Some significant aspects and historical facts about the mini computer system has been summarized as follows :

- They are much smaller in size than the mainframe computer systems. As such they do not occupy an entire room but usually occupy space similar in size to that of a standard refrigerator.
- They are much less expensive than the mainframes.
- Their invention was possible because of the invention of core memory technologies and transistors.
- Minicomputers can can give parallel access to up to 100 users. Hence they were used in places such as business organizations for maintaining billings and finances.
- Some of the very first companies to manufacture the minicomputer systems were Hewlett Packard, DEC and Data General.

A few models of minicomputers which have been a marked success over the years are :

- DEC VAX series and PDP series
- Hewlett Packard HP3000 series
- SDS,SDS-92
- Prime Computers, Prime 50 Series
- Norsk Data, Nord-1, Nord-10, Nord-100
- IBM Midrange Computers
- Control Data Corporation's CDC 160A, CDC-1700
- Data General Nova
- Honeywell-Bull Level 6/DPS Level6/DPS 6000 series

Minicomputershave eventually evolved in to microcomputers. With the launch of microcomputers, thepublic have had a greater access to the advantage of incorporating computers in the daily stride of their lives.

**Supercomputers :**

Supercomputers are one of the many types of modern computing machines which are capable of giving very speedy calculations. It is because of their high speed processing ability that Supercomputer systems are used in such works as animation graphics, weather forecasting, nuclear research work, petroleum research works, crypt analysis, molecular modeling and the likes. You must be wondering then what is the difference between a supercomputer and a mainframe computer system? While Mainframe machines are primarily used for a number of purposes, supercomputers are so designed to serve a singular purpose.

**A brief time line ofthe development of supercomputers has been given as follows :**

**1960s :**Seymour Cray of Control Data Corporation (CDC) launches the Supercomputer systems.**1970s :**Cray Research isfounded by Seymour Cray after he leaves Control Data Corporation (CDC). Most supercomputers were meant for running vector processor.**1985-1990 :**Cray's model of supercomputer takes over the market.**Today,**supercomputers are designed by such companies as HP, IBM and of course, Cray Inc. Supercomputer systems are now becoming almost the same as laptop computers and desktop systems.

- Liquid Cooling
- Striped Disks (RAID)
- Parallel File systems
- Non-uniform memory access (NUMA)
- Vector Processing

When the hardwares of the supercomputers are prepared to serve a special mathematical operation, they are called Special Supercomputers. Currently there are many such types of supercomputers as the GRAPE for molecular dynamics and astrophysics, Deep Crack for cracking DES cipher, Deep Blue for playing chess, etc.

**Last Updated : December 24, 2013**