Classification of Computers | Types of Computer
DEFINITION OF COMPUTER
A computer is a general purpose device that can be
programmed to carry out a finite set of arithmetic or logical
operations. Since a sequence of operations can be readily
changed, the computer can solve more than one kind of problem.
1. CLASSIFICATION OF COMPUTERS ACCORDING TO SIZE, FEATURES AND LATEST VERSIONS OF OPERATING SYSTEMS OF COMPUTERS.
Generations Of Computers
FIRST GENERATION COMPUTERS USED VACUUM TUBES AS SWITCHING DEVICE AND MAGNETIC DRUM FOR MEMORY. THESE COMPUTERS WERE OFTEN HUGE, OCCUPYING AN ENTIRE HALL.
Vacuum Tubes or Valves
The image on the left shows different vacuum tubes.
Because first generation of computers used vacuum tubes, they consumed a lot of electricity and produced excessive heat. You require cooling facilities to operate computers. This was the major problem of this generation of computers. Moreover, these tubes burned out because of too much heating and need to be replaced more frequent.
The operation cost of these computers were too expensive.
In first generation computers, the operating instructions or programs were specifically built for the task for which computer was manufactured. The Machine language was the only way to tell these machines to perform the operations. There was great difficulty to program these computers ,and more when there were some malfunctions.
SECOND GENERATION COMPUTERS (1956-1963) :TRANSISTORS
Transistors replaced vacuum tubes and ushered in the second generation of computers.
By 1948, the invention of the transistor greatly changed the computer’s development. Coupled with early advances in magnetic-core memory, transistors led to second generation computers that were smaller, faster, more reliable and more energy-efficient than their predecessors.
Features of 2nd Generation Computers
1. Transistors were used
2. Core Memory was developed
3. Faster than First Generation computers
4. First Operating System was developed
5. Programming was in Machine Language & Aseembly Language
6. Magnetic tapes & discs were used
7. Computers became smaller in size than the First Generation computers
8. Computers consumed less heat & consumed less electricity
Vacuum Tubes or Valves
SECOND GENERATION COMPUTERS (1956-1963) :TRANSISTORS
Transistors replaced vacuum tubes and ushered in the second generation of computers.
By 1948, the invention of the transistor greatly changed the computer’s development. Coupled with early advances in magnetic-core memory, transistors led to second generation computers that were smaller, faster, more reliable and more energy-efficient than their predecessors.
Features of 2nd Generation Computers
1. Transistors were used
2. Core Memory was developed
3. Faster than First Generation computers
4. First Operating System was developed
5. Programming was in Machine Language & Aseembly Language
6. Magnetic tapes & discs were used
7. Computers became smaller in size than the First Generation computers
8. Computers consumed less heat & consumed less electricity
THIRD GENERATION COMPUTERS (1964-1971)
The computers using small scale integration circuits and medium scale integration circuits are under this class. The invention of IC Chips made it possible to greatly reduce the size of computers with improvement in operation speed (nanoseconds) and reliability.
One of the most noticeable achievement of third generation computers is the development of operating systems. The operating systems allowed the machines to run many different applications. These applications were monitored and coordinated by the computer’s memory.
In 1969 AT&T Bell Laboratories programmers Kenneth Thompson and Dennis Ritchie developed the UNIXoperating system on a spare DEC minicomputer. UNIX was the first modern operating system that provided a sound intermediary between software and hardware. UNIX provided the user with the means to allocate resources on the fly, rather than requiring the resources be allocated in the design stages. The UNIX operating system quickly secured a wide following, particularly among engineers and scientists at universities and other computer science organizations. (Source)
User interface devices such as Keyboards & Monitors started from this generation. This is another important development of third generation.
GUI was started from third generation.
CHARACTERISTICS OF THIRD GENERATION COMPUTERS
- Third Generation Computers were based on integrated circuit (IC) technology.
- Third Generation Computers were able to reduce computational time from microseconds tonanoseconds
- Third Generation Computers utilized operating systems to centrally control and made it possible for multiple programs to run on a computer
- Users interacted with computers through keyboards and mouse rather than traditional punched cards and printers.
- Third Generation Computers devices consumed less power and generated less heat. In some cases, air conditioning was still required.
- The size of Third Generation Computers was smaller as compared to previous computers
- Since hardware of the Third Generation Computers rarely failed, the maintenance cost for it was quite low.
- Extensive use of high-level language became possible in Third Generation Computers.
- Manual assembling of individual components was not required for Third Generation Computers, so it reduced the large requirement of labor & cost. However, for the manufacture of IC chips, highly sophisticated technologies were required
- Commercial production became easier and cheaper.
EXAMPLES
IBM 360
PDP-8
HP2115
FOURTH GENERATION COMPUTERS (1971-PRESENT) :MICROPROCESSORS
The Microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built on a single silicon chip.
Microprocessor
FEATURES
- A microprocessor incorporates the functions of a computer's central processing unit (CPU) on a single integrated circuit (IC),[1] or at most a few integrated circuits.[2]
- It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output. It is an example of sequential digital logic, as it has internal memory.
- Microprocessors operate on numbers and symbols represented in the binary numeral system.
COMPUTERS
FEATURES
- Fourth Generation computers are the modern day computers.
- The Size started to go down with the improvement in the integrated circuits.
- Very Large Scale (VLSI) and Ultra Large scale (ULSI) ensured that millions of components could be fit into a small chip.
- It reduced the size and price of the computers at the same time increasing power, efficiency and reliability. "The Intel 4004 chip, developed in 1971, took the integrated circuit one step further by locating all the components of a computer (central processing unit, memory, and input and output controls) on a minuscule chip."
A Video that gives an inside scoop on 4th Generation Computers
FIFTH GENERATION COMPUTERS
Well, up to fourth generation we saw the how computers evolved as the switching devices improved. Fifth generation computers are future computers.
In 1982 Japan started a project named Fifth Generation Computer Systems Project (FGCS) initiated to create a “fifth generation computer” which was supposed to perform much calculation using massive parallel processing. The project was to create the computer over a ten year period, after which it was considered ended and investment in a new, Sixth Generation project, began. Opinions about its outcome are divided: Either it was a failure, or it was ahead of its time. Anyway, its out of our context for the moment. I just wished to make you aware you of this fact.
Fifth generation computers are anticipated new type of computer based on emerging microelectronic technologies with high computing speeds and parallel processing. Other major expectations out of this generation is the ability to use natural language and acquire artificial intelligence (AI). Computers will be able to learn by its experience. These computers are being made using ULSI (Ultra Large Scale IC) and Bio-Chips.
We can see some development in achieving these features already. Parallel processing, voice recognition systems and some level of intelligence is been already realized.
CLASSIFICATION OF COMPUTERS BASED ON APPLICATION
We can identify three different classes if we look upon how a computer works or what they are applied for – Analog, Digital and Hybrid computers.
Types of Computers
1. Analog Computers
Analog computers are used to process continuous data. Analog computers represent variables by physical quantities. Thus any computer which solve problem by translating physical conditions such as flow, temperature, pressure, angular position or voltage into related mechanical or electrical related circuits as an analog for the physical phenomenon being investigated in general it is a computer which uses an analog quantity and produces analog values as output. Thus an analog computer measures continuously. Analog computers are very much speedy. They produce their results very fast. But their results are approximately correct. All the analog computers are special purpose computers.
2. Digital Computers
Digital computer represents physical quantities with the help of digits or numbers. These numbers are used to perform Arithmetic calculations and also make logical decision to reach a conclusion, depending on, the data they receive from the user.
3. Hybrid Computers
Various specifically designed computers are with both digital and analog characteristics combining the advantages of analog and digital computers when working as a system. Hybrid computers are being used extensively in process control system where it is necessary to have a close representation with the physical world.
The hybrid system provides the good precision that can be attained with analog computers and the greater control that is possible with digital computers, plus the ability to accept the input data in either form.
Classification of Computers According to Size
1. Super Computers
Large scientific and research laboratories as well as the government organizations have extra ordinary demand for processing data which required tremendous processing speed, memory and other services which may not be provided with any other category to meet their needs. Therefore very large computers used are called Super Computers. These computers are extremely expensive and the speed is measured in billions of instructions per seconds.
2. Main Frame Computers
The most expensive, largest and the most quickest or speedy computer are called mainframe computers. These computers are used in large companies, factories, organizations etc. the mainframe computers are the most expensive computers, they cost more than 20 million rupees. In this computers 150 users are able to work on one C.P.U. The mainframes are able to process 1 to 8 bits at a time. They have several hundreds of megabytes of primary storage and operate at a speed measured in nano second.
3. Mini Computers
Mini computers are smaller than mainframes, both in size and other facilities such as speed, storage capacity and other services. They are versatile that they can be fitted where ever they are needed. Their speeds are rated between one and fifty million instructions per second (MIPS). They have primary storage in hundred to three hundred megabytes range with direct access storage device.
4. Micro Computers
These are the smallest range of computers. They were introduced in the early 70’s having less storing space and processing speed. Micro computers of todays are equivalent to the mini computers of yesterday in terms of performing and processing. They are also called “computer of a chip” because its entire circuitry is contained in one tiny chip. Themicro computers have a wide range of applications including uses as portable computer that can be plugged into any wall.
5. Laptop Computers
The smallest computer in size has been developed. This type of small computers look like an office brief case and called "LAPTOP" computer. The laptops are also termed as "PORTABLE COMPUTERS." Due to the small size and light weight, they become popular among the computer users. The businessmen found laptop very useful, during traveling and when they are far away frm their desktop computers. A typical laptop computer has all the facilities available in microcomputer. The smallestlaptops are called "PALMTOP".
MY LAPTOP
Technical Specification of Sony VAIO E Series SVE14A15FN Laptop
| Sales Package | Laptop, Battery, AC Adapter, User Guide and Manuals |
| AUDIO | |
|---|---|
| Sound | Dolby Home Theater Technology, xLOUD and Clear Phase Technology. |
| Speakers | Stereo Speakers |
| Audio Chips | Intel High Definition Audio |
| Internal Mic | Monaural Microphone |
| COMMUNICATION | |
| Ethernet | 10/100/1000 Gigabit LAN |
| Bluetooth | v4.0 HS |
| Wireless LAN | IEEE 802.11b/g/n |
| DISPLAY | |
| Resolution | 1600 x 900 Pixel |
| Screen Size | 14 Inch |
| Screen Type | TFT Colour Display (VAIO Display, LED Backlight) |
| GRAPHICS | |
| Graphic Processor | AMD Radeon HD 7670M |
| Dedicated Graphics Memory Type | DDR3 |
| Dedicated Graphics Memory Capacity | 1 GB |
| INPUT | |
| Keyboard | Backlit Keyboard |
| Web Camera | 1.3 Megapixels |
| Pointer Device | Touchpad (Gesture supported) |
| MACHINE DIMENSIONS | |
| Weight | 2.30 kg |
| Color | Black |
| Dimension | 341 x 33.3 x 245 mm |
| MEMORY | |
| Memory Slots | 2 (unused slots - 1) |
| System Memory | 4 GB DDR3 |
| Expandable Memory | upto 16 GB |
| OPTICAL DISK DRIVE | |
| Optical Drive | DVD SuperMulti Drive |
| Read/Write Speed | Reading Speed - DVD: DVD+R (SL)-8x / DVD+R (DL)-8x / DVD-R (SL)-8x / DVD-R (DL)-8x / DVD+RW-8x / DVD-RW-8x / DVD-ROM-8x / DVD-RAM-5x / CD: CD-ROM-24x / CD-R-24x / CD-RW-24x, Writing Speed - DVD: DVD+R (SL)-8x / DVD+R (DL)-6x / DVD-R (SL)-8x / DVD-R(DL)-6x / DVD+RW-8x / DVD-RW-6x / DVD-RAM-5x / CD: CD-R-24x / CD-RW-10x |
| PLATFORM | |
| Operating System | Windows 7 Home Premium (64-bit) |
| PORTS/SLOTS | |
| Mic In | Yes |
| RJ45 LAN | Yes |
| USB Port | 2 x USB 2.0, 2 x USB 3.0 |
| VGA Port | Yes |
| HDMI Port | Yes |
| Multi Card Slot | Yes |
| POWER | |
| Power Supply | 65 W AC Adapter |
| Battery Cell | VGP-BPS26A Lithium-ion Battery |
| Battery Backup | Up to 5.5 hours |
| PROCESSOR | |
| Brand | Intel |
| Cache | 3 MB (L3 Cache) |
| Chipset | Intel HM76 Express |
| Variant | 2450M |
| Processor | Core i5 (2nd Generation) |
| Clock Speed | 2.5 GHz |
| STORAGE | |
| RPM | 5400 |
| HDD Capacity | 640 GB |
| Hardware Interface | SATA |
