Types of Computer
Since the invention of computers from first generation and fourth generation computers, they have been classified according to their types and how they operate that is input, process and output information.
Computer types can be divided into 3 categories according to electronic nature. Types of computers are classified according to how a particular Computer functions.
The types of computer are
• Analog Computers
• Digital Computers
• Hybrid Computers
Analog Computers
• It uses discontinuous analog signal
• Used in Scientifics research
• It is programmed to perform arithmetic and logical operations
Analog types of Computer uses what is known as analog signals that are represented by a continuous set of varying voltages and are used in scientific research centers, and hospitals.
With analog types of computer values are represented by physical measurable quantities e.g. voltages. Analog computer types program arithmetic and logical operations by measuring physical changes i.e. temperatures or pressure.
Digital Computer
• Have two state 0 and 1(On and Off)
• It works on high speed discrete signal of (0 or 1)
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 digit of 0 and 1 or off state and on state. Digital computer type recognizes data by counting discrete signal of (0 or 1) they are high speed programmable; they compute values and stores results.
The Digital Computer is divided into Four Categories
1. Microcomputers
2. Minicomputers
3. Mainframes
4. Supercomputers
Microcomputers
• Microcomputer is known as Personal Computer or PC in short
• First introduced by IBM
• It was called micro as CPU was created on a single chip called ‘microprocessors.’
The microcomputer is also known as the "Personal Computer". IBM introduced and marketed
the first widely available, commercialized microcomputer named the “IBM PC” where PC stood for Personal Computer. IBM PC became the standard against which all microcomputers were compared and developed, the “PC” helped provide a name for the industry to grow.
The category is termed “micro” because the fundamental component that allowed the categories development was the CPU created on a single chip .The lower costs helped in the development and production of the CPU and various components of the microcomputer allowed microcomputers to become a broad market general purpose computer.
The general appeal or focus of microcomputers on the individual’s enjoyment and productivity has been a key factor in the microcomputer developments and enhancements over the years.
Microcomputers can be grouped into five smaller groups
1. Workstation
2. Desktop
3. Server
4. Laptop and
5. Notebook.
Each referring to the physical usage of the machines and not necessarily the power.
Workstation generally refers to machines used for intensive calculations on designs such as architecture and buildings.
Desktop generally refer to machines used by business people for word processing, spread sheeting etc, and are physically placed onto a desk.
Server: A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running.
The Laptop and the notebook are portable machines. Laptops generally are bigger and clumsier due to the power supply being encased in the box holding the CPU.
The Notebook is generally smaller. Notebooks and laptops can work on batteries allowing the user to work with it in aeroplanes, in the car and places computers are not generally available.
Minicomputers
• Access to more Storage space
• Used to access large amount of data simultaneously
• Mainly used in medium size organization
Faster than the microcomputer with access to more storage space and more input and output devices, the minicomputer is used when large groups need access to data simultaneously. The minicomputer can do this because the hardware is designed for plugging in more devices, and the C.P.U. and support chips are designed more for this kind of work than the microcomputers.
Minicomputers are used by medium sized business and small sites of large organizations. They are also used in factories to control automated assembly lines.
Mainframes
• Have more powerful processor
• Used in large organization
• Capable of processing large amount of data simultaneously
Mainframes have more access to storage space and to input/output devices. To work with these extra devices mainframes also have more powerful 'processors'. This power is useful and required by large corporations who have large amounts of data to Process.
Supercomputers
• Supercomputers have multiple CPU and Processor.
• Mainly used for research and Weather Forecast, natural speech recognition
Supercomputers have been developed from the processing requirements of advanced research projects by engineers, scientists and more recently by other research fields. The Supercomputer is a title generally given to computers with processing power well exceeding those of the fastest mainframes and its focus is processing data and manipulation of the data. A significant difference between mainframes and supercomputers is the primary focus of super computers on processing capabilities independent of the many varied input/output devices expected on mainframes.
The major cause for the development of super-class computers has been the continuing Need in the scientific community for faster and faster calculations. Scientists working on atomic physics, computer intensive calculations such as natural speech recognition continue to require more and more computational speed to test their theorems.
Hybrid Computer
• Combination of both analog and digital computer
• It is used to convert the signal from analog to digital and digital to analog
Hybrid computer types are very unique, in the sense that they combined both analog and digital features and operations. Hybrid computers operate by using digital to analog converter and analog to digital converter. By linking the two types of computer above you come up with this new computer type called Hybrid computer.
2. Computer Hardware-CPU, I/O Devices, Storage Devices, Memory
The hardware of computer is divided into three broad categories:
1. Processor/Processing Unit
2. Memory
3. I/O (input/output).
Processor
The processor is the part of the computer that actually does the computations. This is sometimes called an MPU (Main Processor Unit) or CPU (Central Processing Unit or Central Processor Unit).
A processor typically contains an Arithmetic & Logic unit (ALU), Control Unit (CU).
Arithmetic & Logic Unit (ALU)
An arithmetic & logic unit (ALU) performs integer arithmetic and logic operations. It also performs shift and rotate operations and other specialized operations. Usually floating point arithmetic is performed by a dedicated Floating Point Unit (FPU), which may be implemented as a co-processor.
Control Unit (CU)
Control units are in charge of the computer. Control units fetch and decode machine instructions. Control units may also control some external devices.
Main Storage
Main storage is also called memory or internal memory (to distinguish from external memory, such as hard drives).
RAM is Random Access Memory, and is the basic kind of internal memory. RAM is called “random access” because the processor or computer can access any location in memory (as contrasted with sequential access devices, which must be accessed in order). RAM has been made from transistors, integrated circuits, magnetic core, or anything that can hold and store binary values (one/zero, plus/minus, open/close, positive/negative, high/low, etc.).
Static RAM is called static because it will continue to hold and store information even when power is removed. Magnetic cores are examples of static memory.
Dynamic RAM is called dynamic because it loses all data when power is removed. Transistors and integrated circuits are examples of dynamic memory.
ROM is Read Only Memory (it is also random access, but only for read). ROM is typically used to store things that will never change for the life of the computer, such as low level portions of an operating system.
Data storage device
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers A data storage device is a device for recording (storing) information (data).
Primary Storage
• It is directly accessable by CPU
• It is volatile in nature
• All instruction are stored in primary memory before it can be uesd for processing
• It is fastes among all type of memory
• It has small storage space
Primary storage (or main memory or internal memory), often referred to simply as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required.
Secondary Storage
• It non-volatile ,that is, data remain stored even when the computer is switched off.
• It is slower than primary memory
• It has large storage space
Secondary storage (or external memory) differs from primary storage in that it is not directly accessible by the CPU. The computer usually uses its input/output channels to access secondary storage and transfers the desired data using intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is non-volatile. In modern computers, hard disk drives are usually used as secondary storage.
Tertiary Storage
• It is slower than secondary memory
• Generally used to store large amount of data
• It needs robotics mechanism to insert and remove
• Used in supercomputer as accessing data is slow from Tertiary Storage Device
Tertiary storage or tertiary memory, provides a third level of storage. Typically it involves a robotic mechanism which will mount (insert) and dismount removable mass storage media into a storage device according to the system's demands; this data is often copied to secondary storage before use. It is primarily used for archival of rarely accessed information since it is much slower than secondary storage. This is primarily useful for extraordinarily large data stores, accessed without human operators.
Off-line storage
• Pen drive is an example of off-line storage device
• It reqiures human operater to insert and remove
• It is portable and can be carried with ease
Off-line storage is a computer data storage on a medium or a device that is not under the control of a processing unit.The medium is recorded, usually in a secondary or tertiary storage device, and then physically removed or disconnected. It must be inserted or connected by a human operator before a computer can access it again. Unlike tertiary storage, it cannot be accessed without human interaction.
Input
Input devices are devices that bring information into a computer. Information and commands are issued to the computer by way of input devices. Input device is used to insert data and instructions for processing in the computer.
Examples of input devices include the keyboard, mouse, modem, joystick, digitizing pen and tablet, microphone, touch screens, scanner, camera.
Output
Output devices are devices that bring information out of a computer and present data in a form that people can understand.
Examples of output devices include monitors, printers, and pen plotters.
Since the invention of computers from first generation and fourth generation computers, they have been classified according to their types and how they operate that is input, process and output information.
Computer types can be divided into 3 categories according to electronic nature. Types of computers are classified according to how a particular Computer functions.
The types of computer are
• Analog Computers
• Digital Computers
• Hybrid Computers
Analog Computers
• It uses discontinuous analog signal
• Used in Scientifics research
• It is programmed to perform arithmetic and logical operations
Analog types of Computer uses what is known as analog signals that are represented by a continuous set of varying voltages and are used in scientific research centers, and hospitals.
With analog types of computer values are represented by physical measurable quantities e.g. voltages. Analog computer types program arithmetic and logical operations by measuring physical changes i.e. temperatures or pressure.
Digital Computer
• Have two state 0 and 1(On and Off)
• It works on high speed discrete signal of (0 or 1)
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 digit of 0 and 1 or off state and on state. Digital computer type recognizes data by counting discrete signal of (0 or 1) they are high speed programmable; they compute values and stores results.
The Digital Computer is divided into Four Categories
1. Microcomputers
2. Minicomputers
3. Mainframes
4. Supercomputers
Microcomputers
• Microcomputer is known as Personal Computer or PC in short
• First introduced by IBM
• It was called micro as CPU was created on a single chip called ‘microprocessors.’
The microcomputer is also known as the "Personal Computer". IBM introduced and marketed
the first widely available, commercialized microcomputer named the “IBM PC” where PC stood for Personal Computer. IBM PC became the standard against which all microcomputers were compared and developed, the “PC” helped provide a name for the industry to grow.
The category is termed “micro” because the fundamental component that allowed the categories development was the CPU created on a single chip .The lower costs helped in the development and production of the CPU and various components of the microcomputer allowed microcomputers to become a broad market general purpose computer.
The general appeal or focus of microcomputers on the individual’s enjoyment and productivity has been a key factor in the microcomputer developments and enhancements over the years.
Microcomputers can be grouped into five smaller groups
1. Workstation
2. Desktop
3. Server
4. Laptop and
5. Notebook.
Each referring to the physical usage of the machines and not necessarily the power.
Workstation generally refers to machines used for intensive calculations on designs such as architecture and buildings.
Desktop generally refer to machines used by business people for word processing, spread sheeting etc, and are physically placed onto a desk.
Server: A computer, or a software package, that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, such as a WWW server, or to the machine on which the software is running.
The Laptop and the notebook are portable machines. Laptops generally are bigger and clumsier due to the power supply being encased in the box holding the CPU.
The Notebook is generally smaller. Notebooks and laptops can work on batteries allowing the user to work with it in aeroplanes, in the car and places computers are not generally available.
Minicomputers
• Access to more Storage space
• Used to access large amount of data simultaneously
• Mainly used in medium size organization
Faster than the microcomputer with access to more storage space and more input and output devices, the minicomputer is used when large groups need access to data simultaneously. The minicomputer can do this because the hardware is designed for plugging in more devices, and the C.P.U. and support chips are designed more for this kind of work than the microcomputers.
Minicomputers are used by medium sized business and small sites of large organizations. They are also used in factories to control automated assembly lines.
Mainframes
• Have more powerful processor
• Used in large organization
• Capable of processing large amount of data simultaneously
Mainframes have more access to storage space and to input/output devices. To work with these extra devices mainframes also have more powerful 'processors'. This power is useful and required by large corporations who have large amounts of data to Process.
Supercomputers
• Supercomputers have multiple CPU and Processor.
• Mainly used for research and Weather Forecast, natural speech recognition
Supercomputers have been developed from the processing requirements of advanced research projects by engineers, scientists and more recently by other research fields. The Supercomputer is a title generally given to computers with processing power well exceeding those of the fastest mainframes and its focus is processing data and manipulation of the data. A significant difference between mainframes and supercomputers is the primary focus of super computers on processing capabilities independent of the many varied input/output devices expected on mainframes.
The major cause for the development of super-class computers has been the continuing Need in the scientific community for faster and faster calculations. Scientists working on atomic physics, computer intensive calculations such as natural speech recognition continue to require more and more computational speed to test their theorems.
Hybrid Computer
• Combination of both analog and digital computer
• It is used to convert the signal from analog to digital and digital to analog
Hybrid computer types are very unique, in the sense that they combined both analog and digital features and operations. Hybrid computers operate by using digital to analog converter and analog to digital converter. By linking the two types of computer above you come up with this new computer type called Hybrid computer.
2. Computer Hardware-CPU, I/O Devices, Storage Devices, Memory
The hardware of computer is divided into three broad categories:
1. Processor/Processing Unit
2. Memory
3. I/O (input/output).
Processor
The processor is the part of the computer that actually does the computations. This is sometimes called an MPU (Main Processor Unit) or CPU (Central Processing Unit or Central Processor Unit).
A processor typically contains an Arithmetic & Logic unit (ALU), Control Unit (CU).
Arithmetic & Logic Unit (ALU)
An arithmetic & logic unit (ALU) performs integer arithmetic and logic operations. It also performs shift and rotate operations and other specialized operations. Usually floating point arithmetic is performed by a dedicated Floating Point Unit (FPU), which may be implemented as a co-processor.
Control Unit (CU)
Control units are in charge of the computer. Control units fetch and decode machine instructions. Control units may also control some external devices.
Main Storage
Main storage is also called memory or internal memory (to distinguish from external memory, such as hard drives).
RAM is Random Access Memory, and is the basic kind of internal memory. RAM is called “random access” because the processor or computer can access any location in memory (as contrasted with sequential access devices, which must be accessed in order). RAM has been made from transistors, integrated circuits, magnetic core, or anything that can hold and store binary values (one/zero, plus/minus, open/close, positive/negative, high/low, etc.).
Static RAM is called static because it will continue to hold and store information even when power is removed. Magnetic cores are examples of static memory.
Dynamic RAM is called dynamic because it loses all data when power is removed. Transistors and integrated circuits are examples of dynamic memory.
ROM is Read Only Memory (it is also random access, but only for read). ROM is typically used to store things that will never change for the life of the computer, such as low level portions of an operating system.
Data storage device
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers A data storage device is a device for recording (storing) information (data).
Primary Storage
• It is directly accessable by CPU
• It is volatile in nature
• All instruction are stored in primary memory before it can be uesd for processing
• It is fastes among all type of memory
• It has small storage space
Primary storage (or main memory or internal memory), often referred to simply as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required.
Secondary Storage
• It non-volatile ,that is, data remain stored even when the computer is switched off.
• It is slower than primary memory
• It has large storage space
Secondary storage (or external memory) differs from primary storage in that it is not directly accessible by the CPU. The computer usually uses its input/output channels to access secondary storage and transfers the desired data using intermediate area in primary storage. Secondary storage does not lose the data when the device is powered down—it is non-volatile. In modern computers, hard disk drives are usually used as secondary storage.
Tertiary Storage
• It is slower than secondary memory
• Generally used to store large amount of data
• It needs robotics mechanism to insert and remove
• Used in supercomputer as accessing data is slow from Tertiary Storage Device
Tertiary storage or tertiary memory, provides a third level of storage. Typically it involves a robotic mechanism which will mount (insert) and dismount removable mass storage media into a storage device according to the system's demands; this data is often copied to secondary storage before use. It is primarily used for archival of rarely accessed information since it is much slower than secondary storage. This is primarily useful for extraordinarily large data stores, accessed without human operators.
Off-line storage
• Pen drive is an example of off-line storage device
• It reqiures human operater to insert and remove
• It is portable and can be carried with ease
Off-line storage is a computer data storage on a medium or a device that is not under the control of a processing unit.The medium is recorded, usually in a secondary or tertiary storage device, and then physically removed or disconnected. It must be inserted or connected by a human operator before a computer can access it again. Unlike tertiary storage, it cannot be accessed without human interaction.
Input
Input devices are devices that bring information into a computer. Information and commands are issued to the computer by way of input devices. Input device is used to insert data and instructions for processing in the computer.
Examples of input devices include the keyboard, mouse, modem, joystick, digitizing pen and tablet, microphone, touch screens, scanner, camera.
Output
Output devices are devices that bring information out of a computer and present data in a form that people can understand.
Examples of output devices include monitors, printers, and pen plotters.
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