Computers may be classified in two ways: according to their data handling capability and their physical size.
The computer may be classified into three classes based on its data handling capabilitie
● Analogue Computer
● Digital Computer
● Hybrid Computer
1) Analogue Computer
Analogue computers are intended for the processing of analogue data. Analogue data is continuous data that changes constantly and does not contain discrete values. It is sometimes referred to as continuous data. We may argue that analogue computers are employed in situations when accurate quantities are not required all of the time, such as when measuring speed, temperature, pressure, and current.
In contrast to digital computers, analogue computers take data directly from measuring devices without first transforming it to numbers and codes. Their output is often shown as a reading on a dial or scale, and they measure the continual changes in physical amount. Analogue computers include devices such as a speedometer and a mercury thermometer.
Advantages of utilising analogue computers include the following:
● Real-time operations and processing may be performed simultaneously, and continuous representation of all data is possible within the capabilities of an analogue machine.
● In some situations, it is possible to do computations without the need of transducers to transform the inputs or outputs from analogue to digital electronic form and vice versa, therefore saving time and money.
● The issue can be scaled to fit the dynamic range of the analogue computer, if the programmer knows how to do so. It gives insight into the situation and aids in the understanding of the errors and the consequences of those faults.
Analogue computers are classified into the following categories:
The following are the slide rules: It is one of the most basic forms of mechanical analogue computers available today. It was created for the purpose of doing simple mathematical computations. It is constructed from two rods. In order to conduct the computation, the hashed rod is pushed into position such that it lines up with the marks on the second rod.
In order to do differential calculations, differential analyzers have been created. For the purpose of solving differential equations, it does integration utilising wheel-and-disc techniques.
Al-Jarazi is credited with inventing the castle clock. It had the capability of storing programming instructions. It stood around 11 feet tall and was equipped with a clock, a zodiac, and a display of the solar and lunar orbits, among other things. In addition, this gadget may allow users to customise the length of the day according to the current season.
This sort of analogue computer simulates physical occurrences by using electrical impulses that travel via capacitors and resistors, which are built into the computer. There is no mechanical interaction between the components in this configuration. The voltage of the electrical signal is what causes the relevant displays to appear on the screen.
2) Digital Computer
It is designed to conduct computations and logical processes at a rapid rate and is known as a digital computer. It receives raw data as input in the form of digits or binary numbers (0 and 1), processes it using programmes stored in its memory, and then outputs the results. In today’s world, digital computers include all current computers, including laptops, desktops, and smartphones, that we use at home or at work.
The following are some advantages of digital computers:
● Because of this, you have the ability to store a big quantity of information and access it quickly whenever you need it.
● It is much easier to add new features to digital systems than it is to analogue ones.
● Digital systems may be utilised for a variety of purposes simply by altering the programme, with no modifications to the underlying hardware required.
● Because to advancements in integrated circuit technology, the cost of hardware has decreased.
● Due to the fact that the data is processed digitally, it is extremely fast.
● Because it makes use of error correcting codes, it is extremely dependable.
● Because the output is not impacted by noise, temperature, humidity, or any other qualities of its components, the reproducibility of findings is greater than with other methods.
3) Hybrid Computer
A hybrid computer combines the best characteristics of both analogue and digital computers. It is as quick as an analogue computer and as accurate as a digital computer, and it has the same amount of memory as both. It has the capability of processing both continuous and discrete data. Analogue signals are accepted, and they are converted into digital form before being processed. This makes it a popular choice for specific applications where both analogue and digital data must be handled. In petrol pumps, for example, a processor is used to transform the measurements of gasoline flow into quantities and prices. They are also utilised in aeroplanes, hospitals, and scientific applications, among other places.
The following are some advantages of utilising hybrid computers:
● Because of the all-parallel configuration of the analogue subsystem, the computation speed of the system is extremely fast.
● It provides more accurate and helpful findings since it is precise and quick to create them.
● It has the capacity to solve and manage large equations in real time, which is a significant advantage.
● It is beneficial in the processing of online data.
● The computer may be classified into five categories based on its size:
Supercomputers are the most powerful and fastest computers available. Their primary function is to process large amounts of data. A supercomputer has the capability of processing billions of instructions per second. It is comprised of thousands of processors that are linked.
Among the scientific and technical applications where supercomputers are most useful include weather forecasting, scientific simulations, and nuclear energy research. Roger Cray invented the supercomputer in 1976, and it was the first of its kind.
Supercomputers have the following characteristics or applications:
● It has the capability of decrypting your password in order to increase protection for security purposes.
● When used in animation, it provides outstanding effects.
● It is utilised for virtual testing of nuclear bombs as well as important medical examinations and procedures.
● It has the ability to examine and comprehend climatic trends, as well as forecast weather conditions. It may be used in the NOAA (National Oceanic and Atmospheric Administration) system, which is capable of processing any form of basic and logical data.
● It contributes to the construction of flight simulators for pilots at the novice level who are undergoing training.
● It aids in the extraction of important information from data storage facilities or cloud computing environments. As an illustration, consider insurance firms.
● It has played an important part in the management of the online currency world, which includes the stock market and bitcoin, among other things.
● It aids in the detection of numerous essential diseases as well as the production of correct findings in cases of brain injuries, strokes, and other similar situations.
● Because it properly analyses data gained from investigating the solar system, satellites, and the movement of the Earth, it is beneficial in scientific research domains.
● Furthermore, it is employed in a smog control system, where it anticipates the amount of fog and other pollutants present in the air.
2) Mainframe computer
Large-scale mainframe computers are capable of supporting hundreds or thousands of users at the same time. They have the capability of supporting many programmes at the same time. It implies that they are capable of running several processes at the same time. These characteristics of mainframe computers make them particularly well suited for large businesses, such as those in the banking and telecommunications sectors, that must handle and analyse large amounts of data.
Large-scale mainframe computers are capable of supporting hundreds or thousands of users at the same time. They have the capability of supporting many programmes at the same time. It implies that they are capable of running several processes at the same time. These characteristics of mainframe computers make them particularly well suited for large enterprises such as banks and telecommunications companies that must handle and analyse a large volume of data that necessitates integer operations such as indexing, comparisons, and so on.
Characteristics of mainframe computers include the following:
● It has the ability to handle massive amounts of data, such as millions of transactions in a second in the banking industry.
● It has an extremely long shelf life. After appropriate installation, it has the potential to operate without interruption for up to 50 years.
● It provides exceptional performance when dealing with big amounts of memory.
● Other processors and input/output terminals are able to share or divide the burden that it is putting on the system.
● Mainframe computers have a lower possibility of introducing errors or flaws throughout the processing process. Any errors that occur may be corrected promptly and without compromising the overall performance.
● It has the capacity to safeguard the stored data and other continuing communication of information and data.
Applications of mainframe computers:
● In health care, it enabled hospitals to retain a database of their millions of patients in order to contact them for treatment or connected to their appointment, drug updates or disease updates.
● In the sphere of defence, it permits the defence departments to communicate a vast amount of sensitive information with other branches of defence.
● In the realm of education, it allows huge institutions to store, manage and retrieve data relating to their courses, admissions, students, professors, workers and associated schools and colleges.
● In the retail industry, the retail organisations who have a vast client base and branches employ mainframe computers to handle and execute information connected to their inventory management, customer management, and huge transactions in a short time.
3) Miniframe or Minicomputer
It is a midsize multiprocessing computer. It comprises of two or more CPUs and may accommodate 4 to 200 users at one time. Miniframe computers are utilised in colleges and departments for functions such as billing, accounting and inventory management. A minicomputer stands between the mainframe and microcomputer since it is smaller than mainframe but larger than a microcomputer.
Characteristics of miniframe or minicomputer:
● It has low weight that makes it simple to carry and fit anyplace.
● It is less costly than mainframe computers.
● It is quite quick relative to its size.
● It remains charged for a long period.
● It does not require a regulated operational environment.
Applications of minicomputers:
A minicomputer is usually used to accomplish three principal purposes, which are as follows:
● Process control: It was used for process control in manufacturing. It basically serves two key duties that are gathering data and feedback. If any irregularity happens in the process, it is detected by the minicomputer and appropriate changes are done accordingly.
● Data management: It is a great gadget for small enterprises to collect, store and distribute data. Local hospitals and motels can use it to retain the records of their patients and clients correspondingly.
● Communications Portal: It may also fulfil the role of a communication device in bigger systems by serving as a portal between a human operator and a central processor or computer.
Workstation is a single user computer that is meant for technical or scientific tasks. It features a faster microprocessor, a big quantity of RAM and high speed graphic adapters. It typically does a certain function with high skill; thus, they are of numerous varieties such as graphics workstation, music workstation and engineering design workstation.
Characteristics of workstation computer:
● It is a high-performance computer system built for a single user for commercial or professional usage.
● It features bigger storage space, better graphics, and more powerful CPU than a personal computer.
● It can handle animation, data analysis, CAD, audio and video creation and editing.
● Any computer that contains the following five properties, may be labelled as a workstation or can be utilised as a workstation.
● Multiple Processing Cores: It has more processor cores than basic laptops or PCs.
● ECC RAM: It is given with Error-correcting code memory that may cure memory problems before they influence the system’s performance.
● RAID (Redundant Array of Independent Disks): It refers to numerous internal hard drives to store or process data. RAID may be of numerous forms, for example, there might be several drives to process data or mirrored drives where if one drive does not work than other continues operating.
● SSD: It is superior than conventional hard-disk drives. It does not contain moving components, hence the risks of physical failure are quite small.
● Optimized, Higher end GPU: It decreases the burden on CPU. E.g., CPU needs to do less work when processing the screen output.
Microcomputer is also known as a personal computer. It is a general-purpose computer that is meant for individual usage. It has a microprocessor as a central processing unit, memory, storage area, input unit and output unit. Laptops and desktop computers are examples of microcomputers. They are appropriate for personal work that may be making an assignment, viewing a movie, or at workplace for office job.
Characteristics of a microcomputer:
● It is the smallest in size among all sorts of computers.
● A restricted number of software can be utilised.
● It is meant for personal work and applications. Only one user can work at a time.
● It is less expansive and easier to utilise.
● It does not require the user to have particular skills or training to utilise it.
● Generally, comes with single semiconductor chip.
● It is capable of multitasking such as printing, scanning, surfing, viewing movies, etc.