Computer Fundamental – A computer is an electronic device designed to process information. Computers rely on programs to function and cannot operate without them. They represent decimal numbers using binary digits. The term “computer” often encompasses the Central Processing Unit (CPU) along with internal memory.
Charles Babbage is Known as the “Father of the Computer.” Charles Babbage conceptualized the first mechanical computer, named the Analytical Engine. This device utilized read-only memory in the form of punch cards.
Definition of a Computer Fundamental
A computer can be defined in multiple ways, depending on its methods of operation and its performance. Below the some definitions of a computer:
- Functioning as an electronic apparatus, a computer acquires input from users, processes data following a set of instructions (known as a program), produces output, and stores data for future utilization. Computers are capable of performing both numerical and non-numerical tasks, encompassing arithmetic and logical calculations.
- The word ‘computer’ comes from the word ‘compute’, which means to calculate. So a computer is normally considered to be a calculating device that can perform arithmetic operations at enormous speed.
These definitions highlight different aspects of what a computer is and how it functions in our modern world
- Electronic Device for Processing Data: A computer is an electronic device designed to process and manipulate data, performing various tasks based on instructions given to it.
- Programmable Machine: A computer is a programmable machine that can execute a set of instructions, known as programs, to perform tasks and solve problems.
- Information Processor: A computer is an information processor that takes in data, processes it through various operations, and produces meaningful results.
- Digital Data Manipulator: A computer is a digital data manipulator that transforms raw data into meaningful information using mathematical and logical operations.
- Data Processing Device: A computer is a data processing device capable of performing arithmetic, logical, and data manipulation operations on input data to generate output.
- Automated Calculator: A computer is an automated calculator capable of performing complex calculations and repetitive tasks accurately and efficiently.
- Binary Code Interpreter: A computer is a binary code interpreter that reads and executes instructions represented in binary format, the language of computers.
- Information Storage and Retrieval System: A computer serves as an information storage and retrieval system, allowing users to store, organize, and access data and files.
- Multifunctional Tool: A computer is a versatile tool that can handle various tasks such as communication, entertainment, research, design, and more.
- Digital Brain: A computer acts as a digital brain, processing information, making decisions based on programmed logic, and emulating human cognitive functions.
More accurately, a computer may be defined as a device that operates upon information or data. Data can be anything like bio-data, employee details, or the details of the students when the computer is used to prepare the results, employees’ details and the railway reservations, or a number of different types in case of application of computers for scientific research problems, etc.
Thus data comes in various shapes and sizes depending upon the type of computer application. A computer can store process and retrieve data as and when desired. The fact that computers process data is so fundamental that many people have called it’s as a ‘data processor’.
Basic Functions of a Computer
- Step 1 − Accepts data as input.
- Step 2 − Saves the data/instructions in its memory and utilizes them as and when required.
- Step 3 − Execute the data and convert it into useful information.
- Step 4 − Provides the output.
- Step 5 − Have control over all the above four steps.
Genaration of computer
| First Generation (1940-1952) | Very small size, less maintinence, very fast speed and completely responsible. Less spend of electricity, more comfortable, Today it’s known as Personal Computer (P.C.) |
| Second Generation (1952-1964) | Small size and less maintenance as well as fast speed & more responsible from the second generation, but less than fourth generation. |
| Third Generation (1964-1971) | Small size, more maintenance, fast speed & more responsibility from first generation, but less than third generation. |
| Fourth Generation (1971- present) | Very small size, less maintinence, very fast speed and completly responsible. Less spend of electricity, more comfortable, Today it’s known as Personal Computer (P.C.) |
| Fifth Generation (Present to Beyond) | Based on artificial intelligence, uses the Ultra Large-Scale Integration (ULSI) technology and parallel processing method (ULSI has millions of transistors on a single microchip and Parallel processing method use two or more microprocessors to run tasks simultaneously). |
Following are some examples of some ancient computers:
Punched Card Machines: Punched card devices had their immediate origins Hollerith’s work in the late 1890s and can be considered to be successors to the jacquard loom. These machines worked by using mechanical process to count paper cards punched in various patterns. By 1930s punched card machines had become sufficiently complex that they could perform scientific tasks. For example, in England, I.J. Corine used punched card machines to compute lunar motion table.
Analog Computers: An analog computer performs computations not by logic, but by analogy; that is, by using a representation of a quality and manipulating it electrically or mechanically. An analog computer might represent numbers by voltage levels and perform arithmetic by means of voltage adders or some other method.
The prime examples of analog computers were the differential analyzer and various analog devices used in gunnery.
Relay Calculators: Relay calculators were the successors to mechanical calculators (which were still used heavily in the 1940s). Relay calculators could not only do arithmetic, but also sequences of calculations automatically by using the switching ability of the relays. These relay machines include Howard Aiken’s Harvard mark I and mark II (famous for Grace Hopper’s discovery of the first ‘bug’, a moth stuck in the relays of the machine) as well as machines built by Stibitz at Bell Labs and Zeus’s machines in Germany.
Parts of Computer
- Input unit
- Output unit
- Central Processing unit (C.P.U.)
1. Input Unit: The units, which are used for giving the data from user to computer, are known as input unit.
Examples of these units are Keyboard, Mouse, Light pen, Scanner, Mike, and Touch Screen etc.
2. Output Unit: The units, which are used from computer to display or giving the data to user, are known as output unit.
Examples of these units are Monitor, Speaker, and Printer etc.
3. Central Processing Unit: The CPU is the brain of any computer system. In a human body the brain takes all major decisions and the other parts of the body functions as directed by the brain. Similarly, in a computer system all major calculations and comparisons and made inside the CPU and the CPU is also responsible for the activating and controlling the operations of the other units of a computer system.
Parts of C.P.U. are given following:
Arithmetic Logic Unit (ALU): The arithmetic logic unit of a computer system is the place where the actual execution of the instructions takes place during the processing. All calculations are performed and all comparisons are made in the ALU. The data and instructions stored in the primary storage prior to processing are transferred as and when needed to the ALU where processing takes place.
No processing is done in the primary storage unit. Intermediate results generated in the ALU are temporarily transferred back to the primary storage unit needed at a later time. Data may thus move from primary storage to ALU and back again to storage many times before the processing is over. After the completion of processing, the final results, which are stored in the storage unit, are released to an output device.
The type and number of arithmetic and logic operations that a computer can perform is determined by the engineering design of the ALU. However, almost all ALU’s are designed to perform the four basic arithmetic operation: add, substract, multiply, device and logic operations are comparisons such as less than, equal to are greater than.
Control Unit (CU): By selecting interpreting and seeing to the execution of the programmed instructions, the control unit is able to maintain order and direct the operation of the entry system. Although, it does not perform any actual processing on the data, the control unit acts as a central nervous system for the other components of the computer. It manages and co-ordinates stored in main memory, interprets system to execute them.
The control unit and the arithmetic logic unit of a computer system are jointly known as the central processing unit (CPU).
Some other main parts used in Computer are following:
Integrated Chip (IC): A circuit can be fabricated in a tiny piece of silicon rather than semiconductor material such as silicon. These components assembling several describe components in to the same circuit. Hundred or thousands of transistors could be fabricated on a signal wafer of silicon. These fabricated transistor can be connected which a process of metallization of form logic circuit on the some chip they have been produced.
Digital circuit are constructed which in integrated circuits. An integrated circuit is small silicon semiconductors crystal called a chip containing the electronic components for the digital gate.
Microprocessor: Initially the integrated circuit contained only about ten to twenty components. This technology was named small scale integration (SSI) later which the advancement of technology for manufacturing ICs its become possible to integrate up to hundred components on a single chip.
This technology came to be known as medium scale integration (MSI) when it was possible to integrate over 30,000 components on to a single chip. Effort is still on for further miniaturization and it expected that more than one single chip know as very large scale integration (VLSI). Thus the single chip processor is known as microprocessor. The Intel 4004 was the first microprocessor. Intel 8080 came in 1974 and this was the first general-purpose microprocessor.
The microprocessor technology is related to ICs technology. In IC’s technology the more and more components were fabricated on chip. In microprocessor technology putting all the components on a single chip.
Classification of Computers:
- Micro Computer
- Mini Computer
- Mainframe Computer
- Super Computer
Micro Computer: The Microprocessors gets its name from the facts that their main component, the microprocessors, is located on one-integrated circuit components. Microcomputers fit nicely on desktop. For that reason they rate some time know as desktop computers.
Many individuals purchase microcomputers for personal use, either for their jobs or for other purpose. Microcomputers then are also known as personal computer. Very large scale integrated (VLSI) technology is used in microcomputers and its become very small size and high capacity computer. Laptop computer is a part of microcomputer.
Mini computer: Mini computer more properly called medium size computers are smaller, slower and less expansive than mainframes. They have known special power or environmental control requirement- so they can be located conveniently throughput an organization’s facility. They can support a network of user terminals but not as many mainframes can.
They can store and retrieve data from the some types of input and output device as mainframes, but they have a smaller storage capacity 1970 almost all mini computers were 16 bits marching-Gradually the architectural requirement of mini computers grew and a 32 bit mini computer, which has called super mini, was introduced. The supermini had more peripheral device, large memory and could support more users working simultaneously on the computer in compression to previous mini computers.
Mainframe Computer: Mainframe make up the bulk of the computer installation in large organizations at least in the seems that they do more data processing work that any other types of computers. Mainframe computers often serve more than one user at the time because they are able to support large networks of individuals terminals companies and government agencies, all use mainframe computer through they often use either types as well. Most professional programmers work in a mainframe environments, preparing new program maintain existing ones.
Super Computer: A commercial computer with vector instruction and pipeline floating-point arithmetic operations referred to as super computer., Super computer are very powerful high performance machine used mostly for scientific computations. To speed up the operations, the components are packed tightly tighter to minimize the distance that the electronic signals have to travel. Super computer also used special techniques for removing the heat from circuit it prudent then from burning up because is their close proximity.
The instructions set of super computer contains the standard data transfer, data manipulation and control instruction of conventional computers. A super computer is a computer system best know for its high computational speed fast and large memory system, and the extensive use of parallel processing.
The first super computer developed in 1976 is the CRAY- 1 super computer. It uses vector processing with 12 distinct functional units in parller.
Another early model supercomputer is the FUJITSU VP-200. It has a scaler processor and a vector processor that can operate concurrently. The newer VP-2600 uses a clock cycle of 3.2 has and claims a peak performance of 5 gigaflops.
The Von-Naumann machine can be addressed in independently and carried out a sequential fashion from on instruction to the next. But in super computer the memory and speed is very high and execute the problems in any sequence not only sequential fashion.
The Super Computers developed in India
| Super Computer | Made by the institution |
| Param 100 | Centre for Development of advanced computing (See-Dace Pune, Establish. 1988) |
| Param Anant | Centre for Development of advanced computing (See-Dace Pune, Establish. 1988) |
| Param 800 | Centre for Development of advanced computing (See-Dace Pune, Establish. 1988) |
| Param 8600 | Centre for Development of advanced computing (See-Dace Pune, Establish. 1988) |
| Param 9000 | Centre for Development of advanced computing (See-Dace Pune, Establish. 1988) |
| Mach | Indian Institute of Technology (I.I.T.), Mumbai |
| Pace | Advanced Numerical Research And Analysis Group (ANURAG), Hayatabad |
| Tera Flop | Bhabha Atomic Research Centre (BARC) |
| Multi Micro | Indian Science Research, Benglore |
Memory of Computers
Ram and ROM:
- RAM (Random Access Memory): RAM is a general-purpose device whose contents can be altered during the computational process. In RAM the memory cells can be accessed for information transfer from any desired random location. That is the process of locating a word in memory is the same and requires an equal amount of time no matter where the cells are located physically in memory thus the name ‘Ramdon Access’.
- ROM (Read Only Memory): As the name implies a read only memory is a memory unit that performs the read operations only, it does not have a write capacity. This implies that the binary information stored in in a ROM is made permanent during the hardware production of the unit and cannot be altered by writing different words in to it.
Cash Memory: A special very high-speed memory is some times used to increase the speed of processing by making currants programs and data available to the CPU at a rapid rate.
As the name implies Cash memory is a memory in hiding and is not addressable by the user of the computer system. Its purpose is to look ahead and toil provide the CPU with currently needed information. Cash memory makes main memory appear to be faster and a larger than it really is. It is very expensive as compared to the main memory and hence its size is normally very small. The most important effect of Cash memory is in improving the memory transfer rates and thus raising the processor speed.
Main Memory: The main memory is the central storage unit in a computer system. It is a relatively large and fast memory used to store programs and data during the computer operations. The principal technology used for the main memory is based on semiconductor integrated circuits. Integrated circuit RAM chips are available in two possible operating modes astatic and dynamic.
The static RAM consists essentially of internal flip-flop that store the binary operation. The stores information remains valid as long as power is applied to the unit. The dynamic RAM is stored the binary information in the form of electronic charges that are applied to capacitors. The dynamic Ram offers reduced power consumption and larger storage capacity in a single memory chip.
Secondary or Auxiliary Memory: This memory is slower but very large than the primary memory. It is desirable that the operating speed of the primary storage of a computer be as fast as possible because most of the transfers of data to and from the processing unit is via the main memory.
Harddisc is an example of secondary memory.
Virtual Memory: A virtual memory system facilitates its users to use a large addressable memory space without working about the size limitations of the physical main memory.
Computer Software & Operating System
System Software: System software is a set of one or more programs designed to control the operation of a computer system. These programs are general programs written to assist humans in the use of the computer system by performing tasks, such as controlling all of the operations, required to move data into and out of a computer and all the steps in the executing an application program.
In general system package support the running of other software communicate with peripheral devices. Thus the system software makes the operation of the computer system move effective and efficient. The programs included in a system are called System Programs.
Operating System: An operating system is an integrated set of programs that is used to manage the various resources and overall operation of computer system. It prime objective is to improve the performance and efficiency of a computer system and increases facility, the ease with which a system can be used. It makes the computer system user friendly. That is, its make the easier for people to interface with the make use of computer.
Computer Network
A computer network is a method that links two or more computers in order to communicate with each other. A computer network provides the opportunity for users to shared computer hardware, software, data and work collaboratively on projects.
The International Standard Organization (ISO) model of networking defines the network as a service of layers. Each layer has special function. Each layer provides services to the higher layer and uses the services of lower layers.
Local Area Network (LAN), Wide Area Network (WAN), Global Network (Internet) is the some examples of networks.
There are seven layers of the ISO model:
| 1. | Physical Layer | It defines transmission speed, modulation and encoding. |
| 2. | Data Link Layer | It established the logical link between two computers on a network. |
| 3. | Network Layer | It responsible for routing packets from the sender to the receiver. |
| 4. | Transport Layer | It has the responsibility of checking that all message are delivered to higher layers without any error. |
| 5. | Session Layer | It creats a session so that an application of two computers can talk with each other. |
| 6. | Presentation Layer | It translates application data to recognised format for transmission across the network. |
| 7. | Application Layer | It provides needed information and service to the user. |
Analog and digital Transmission
Data is propagated from one point to another by means of electronic signals, which may be in digital or analog form.
Analog Signal: In an analog signal the transmitted power waves. The amplitude of analog signal the transmitted power varies over a continuous range of example – sound, light and radio waves. The amplitude of analog signals is measured in volts and its frequency in Hz (Hertz).
Digital Signal: Digital data are to be sent over an analog facility, the digital signals must be converted to analog form. The technique by which a digital signal is converted to its analog form is known Analog Signal; as ‘modulation.’ The reverse process, that is the conversion of analog signal to its digital form at a destination device, is called ‘demodulation.’
Router & Bridge: Routers provide connectivity between two local area network (LAN) or two wide area network (WAN) over large geographical distance. All routers participate in a routing protocol to access the network topology and based on this information routers compute the best route from a sender to receiver.
Bridge are used to connect two LANS that use identical protocols over a wide area. The bridge acts as an address filter which picks up packets from one LAN that are intended for a destination on another LAN and poasses these packets on the network.
Modem: It converts Digital Signal to Analog Signal and Analog Signal to Digital Signal. The conversation of Digital Signal to Analog Signal are known as ‘Modulation’, and the conversation of Analog Signal to Digital Signal are known as ‘Demodulation’.
Types of Network
- Local Area Network (LAN)
- Wide Area network (WAN)
- Metropolitan Area Network (MAN)
Local Area Network (LAN) : LAN is a network that combined to small area such as a building or a small campus.
Wide Area Network (WAN) : WAN is a network that covers a bigger geographical area than a LAN and uses the telephone lines, setelight, microwave or a combination of them for commuinication.
Metropolitan Area Network (MAN) : A network that covers a large city and its surrounding areas is called a Metropolitan Area Network (MAN).
Internet: The Intermate is a network of networks, which utilize a common protocol (TCP/IP) for communication. It is a collection of communication tools, which links millions of computers from arround the world. It provides an opportunity to share information, database and resources.
Every computer on the Internet has its own unique address (IP). It has become a potential resource for business, learning, research and communication.
The Internet has provided the following opportunities :
- Sending and receiving e-mail.
- Participate in synchronous (chat and video conferencing) ans asynchronous (e-mail and bulletin board) group and individual communication.
- Do shopping and business transaction.
- Search database.
- Access database and run application from remote site.
- Participate in formal and informal educational activities.
Intranet : It is a network that is combined within an organization. It allows a group of users to access and share resources. It looks like a private club where only a member of the club can access the club’s facilities and resources.
Extranet : When part of the resources of the Internet is accessible to customers, suppliers and outside partners, that part is calles an extranet. Companies use extranets to exchange data, share products and collaborate in training and services.
Transmission Control Protocol And Internet Protocol
TCP/IP stands for Transmission Control Protocol And Internet Protocol. It is a collection of protocols and roles that control data transmission across network. Internet communication and transmission are based on TCP/IP. TCP/IP was developed by the Department of Defense in order to connect different networks designed by different vendors. TCP/IP is installed for every computer on the network.
Three important pieces of data should be provided to the system during the installation of TCP/IP.
- The IP address of the computer
- The subnet mask
- The IP address of the gateway (router)
TCP: It manages the packing data into packets that are transmittable across the Internet and unpacking at the destination to retrive the original data. In the casde of data error or loss, TCP is responsible for transmission of the data until delivery to the destination is completed.
IP: It manages the address of each packet in order to get it to right destination. Each router (gateway) on the network checks the IP address in order to determine whether to broadcast it to the local network or forward over the backbone. The IP address is four bytes in of value separated by a period and each byte is a decimal number between 0 and 255.
For Example, an IP address at Ball State University is 147.226.78.71 (class C). The first three bytes (147.226.78) are the network address while the last byte (71) is the node address.
Computer Virus
A virus is a simply a computer program that is intentionally written to attach itself to other programs or disk boot sectors and replicate whenever those programs are executed or those infected disks are accessed. Viruses, as purely replicating entities, will not horm our system as long as they are coded properly. Any system damage resulting from a purely replicating virus happens because of bugs in the code that conflict with the system’s configuration.
In other words a well-written virus that only contains code to infect programs will not damage our system. Our programs will contain the virus, but no other harm is done. The real damage – The erasing of files, the formatting of hard drives, the scrambling of partition tables, etc. – is caused by international destructive code contained within the virus.
Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.
At a deeper level there are similarities as well. A biological virus is not a living thing. A virus is a fragment of DNA inside a protective jacket. Unlike a cell, a virus has no way to do anything or to reproduce by itself – it is not alive. Instead, a biological virus must inject its DNA into a cell. The viral DNA then uses the cell’s existing machinery to reproduce itself. In other case the new virus particles bud off the cell one at a time and the cell remains alive.
Computer viruses are various types. The latest thing is the e-mail virus, and the Melissia virus in March of 1999 was spectacular. Melissa spread in Microsoft Word documents sent via e-mail, and it worked like this. Someone created the virus as a Word document uploaded to an Internet newsgroup. Anyone who downloads the document and opened it would trigger the virus. The virus would then send the document in an e-mail message to the first 50 people in the person’s address book.
The e-mail message contained a friendly note that included the person’s name, so the recipient would open the document thinking it was harmless. The virus would then create 50 new messages from the recipient’s machine. As a result, the Melissa virus was the fastest-spreading virus ever seen! As mentioned earlier, it forced a number of large companies to shut down their e-mail systems.
The I LOVE YOU virus, which appeared on May 4,2000, was even simpler. It contained a piece of code as an attachment. People who double clicked on the attachment allowed the code to execute. The code sent copies to itself to everyone in the victim’s address book and then started corrupting files on the victim’s machine. This is as simple as a virus can get. It is really more of a trojan horse distributed by e-mail than it is a virus.