History of computing and informatics

INTRODUCTION

By presenting this work, we hope that it will be of interest to you and help you delve into all the topics that will be developed below.

Waiting for this work to meet the expectations created and serve as a basis for future references on topics of such relevance and importance in these days of high and advanced technology.

TOPIC I

HISTORY OF COMPUTING

1.1 HISTORICAL OVERVIEW

It all started with machines designed to handle numbers, this is how we refer to Abacus, invented by the Babylonians back in 1000 BC. Mainly used by the Chinese to carry out simple operations, it is made up of a tablet with a series of beads that can be used to add and subtract.

Just before he died in 1617, Scottish mathematician John Napier (best known for his invention of logarithms) developed a set of sticks to calculate which he called "Napier Bones." So named because the ivory or bone twigs were carved, the "bones" entered the logarithmic system. Napier's Bones had a strong influence on the development of the sliding rule (five years later) and subsequent calculating machines that counted on logarithms.

In 1621 the first sliding rule was invented by that of the English mathematician William Oughtred. The sliding ruler (called "Proportion Circles") was a set of rotating discs that were calibrated with Napier's logarithms. One of the earliest gadgets in analog computing, the sliding ruler was typically used (in a linear order) until the early 1970s, when portable calculators became more popular.

In 1623 the first mechanical calculator was designed by Wilhelm Schickard in Germany. Called "The Calculating Clock," the machine incorporated Napier's logarithms, rolling cylinders in a large lodge. A Calcualdor Clock was commissioned for Johannes Kepler, the famous mathematician, but was destroyed by fire before it was finished.

One of the most direct ancestors of the current computer, it was created by the French scientist Blaise Pasca in the seventeenth century (1642). At 18 years old, Pascal invented his first calculating machine, capable of adding and subtracting; and all this based on crimping multiple gear wheels.

In 1666 the first multiplication machine was invented by Sir Samuel Morland, then Master of mechanics at the court of King Charles II of England. The apparatus consisted of a series of wheels, each representing ten dies, hundreds, etc.

A steel pin moved the dials to perform the calculations. Unlike the Pascaline, the device had no automatic column feed.

Years later, in 1673, Gottfied Von Leibnitz perfected Pascal's studies, and came to build a machine that not only added and subtracted, but also multiplied, divided, and even calculated square roots.

In 1769 the Automata Chess Player was invented by Baron Empellen, a Hungarian nobleman. The apparatus and its secrets were given to Johann Nepomuk Maelzel, an inventor of musical instruments, who toured Europe and the United States with the apparatus, in the late 1700s and early 1800s. Pretending to be a pure machine, the Automata included a player of "robotic" chess. The Automaton was a sensation wherever it went, but many commentators, including the famous Edgar Allen Poe, have written detailed reviews saying that it was a "pure machine." Instead, it was generally believed that the device was operated by a human hidden in the closet under the chessboard. The Automat was destroyed in a fire in 1856.

The first logical machine was invented in 1777 by Charles Mahon, the Earl of Stanhope. The "logic demonstrator" was a pocket-sized device that solved traditional syllogisms and elementary probability questions. Mahon is the forerunner of logic components in modern computers.

In 1790 Joseph-Marie Jacquard (1572-1834) used punch cards to control a loom.

The Jacquard Loom was invented in 1804 by Joseph-Marie Jacquard. Inspired by musical instruments that were programmed using perforated paper, the machine resembled a loom tether that could automatically control drawings using line perforated cards. Jacquard's idea, which revolutionized silk spinning, was to form the basis of many computing devices and programming languages.

The first mass production calculator was distributed, beginning in 1820, by Charles Thomas de Colmar.

Originally sold to Parisian insurance houses, Colmar's "arithmometer" operated using a variation of Leibniz's wheel. Over a thousand arithmometers were sold and he eventually received a medal at the International Exhibition in London in 1862.

1.2 PIONEERS OF COMPUTING

Blaise Pascal, Gottfied Von Leibnitz, Charles Babbage, Augusta Byron Herman Hollerith, James Powers, Alan Turing, Konrad Zuse, John Von Neumann, Chuck Peddle, Linus Trovlas, Bill Gates.

1.3 DEFINITIONS OF COMPUTER

Machine capable of carrying out a sequence of operations by means of a program, in such a way that processing is performed on one set of input data, obtaining another set of output data.

Electronic device capable of receiving a set of instructions and executing them by calculating numerical data, or compiling and correlating other types of information.

It is a high-power electronic calculator equipped with high-capacity memories and peripheral devices, which allows to solve very complex arithmetic and logic problems very quickly and without human intervention during the process.

1.4 THE FIRST COMPUTER

It was in 1830, when the operating principles of modern computers were established. His paternity is due to the English mathematician Charles Babbage, who after launching the so-called differential machine in 1822 - with no less than 96 cog wheels and 24 axles, launched himself in pursuit of his most relevant project: the analytical machine (1833).

The first computer was the analytical machine created by Charles Babbage, a mathematical professor at the University of Cambridge in the 19th century. Charles Babbage's idea of ​​a computer was born because making mathematical tables was a tedious and error-prone process. In 1823 the British government supported him to create the project of a difference machine, a mechanical device to carry out repeated additions.

Meanwhile Charles Jacquard (French), a fabric maker, had created a loom that could automatically reproduce fabric patterns by reading the information encoded into hole-punched patterns on rigid paper cards. Upon learning of this method Babbage abandoned the difference machine and went to the project of the analytical machine that could be programmed with punched cards to perform any calculation with a precision of 20 digits.

In 1944, the Mark I was built at Harvard University, designed by a team led by Howard H. Aiken. This machine is not considered as an electronic computer because it was not for general purpose and its operation was based on electromechanical devices called relays.

1.5 TYPES OF COMPUTERS

1. Analog

The analog computer is the one that accepts and processes continuous signals, such as: fluctuations in voltage or frequencies. Example: The thermostat is the simplest analog computer.

2. Digital

The digital computer is the one that accepts and processes data that has been converted to the binary system. Most computers are digital.

3. Hybrid

The hybrid computer is a digital computer that processes analog signals that have been converted to digital form. It is used for process control and robotics.

4. Special purpose

The special purpose computer is dedicated to a single purpose or task. They can be used to produce weather reports, monitor natural disasters, take gasoline readings, and as an electric meter. Example: remote control cars, microwave oven, digital clocks, cameras, word processor, etc.

5. General purpose

The general-purpose computer is programmed for a variety of tasks or applications. They are used to perform mathematical, statistical, commercial accounting, inventory control, payroll, inventory preparation, etc. calculations. Example: "mainframes" or minicomputers.

Computer Categories

• Supercomputer

The supercomputer is the maximum in the computer, it is the fastest and, therefore, the most expensive. It costs millions of dollars and is made from two to three a year. They process billions of instructions per second. They are used for scientific work, particularly to create real-world mathematical models, called simulations.

• Mainframe

Mainframes are large, light computers capable of using hundreds of input and output devices. They process millions of instructions per second. Its operational speed and processing capacity make big business, the government, banks, universities, hospitals, insurance companies, airlines, etc. trust them. Its main function is to process large amounts of data quickly. This data is accessible to the users of the «mainframe» or to the users of the microcomputers whose terminals are connected to the «mainframe». Its cost ranges from several hundred thousand dollars to a million. They require a special system to control temperature and humidity. They also require specialized professional staff to process the data and maintain it.

• Minicomputer

The minicomputer was developed in the 1960s to carry out specialized tasks, such as handling communication data. They are smaller, cheaper, and easier to maintain and install than "mainframes." Its cost is between fifty thousand to several hundred thousand. Used by businesses, colleges, and government agencies. Its market has been declining since microcomputers emerged.

• Microcomputer

The microcomputer is known as a personal computer or PC. It is the smallest, thanks to the microprocessors, cheapest and most popular on the market. Its cost ranges from several hundred dollars to several thousand dollars. It can function as a standalone unit or be networked with other microcomputers or as a terminal of a "mainframe" to expand its capabilities. You can execute the same operations and use the same programs as many superior computers, although in a smaller capacity. Examples: MITS Altair, Macintosh, Apple II series, IBM PC, Dell, Compaq, Gateway, etc.

1.6 GENERATIONS OF COMPUTERS

First generation

In this generation there was a great lack of knowledge of the capabilities of computers, since a study was carried out at this time that determined that twenty computers would saturate the United States market in the field of data processing.

This generation spanned the 1950s. And it is known as the first generation. These machines had the following characteristics:

• These machines were built by means of vacuum tubes and were programmed in machine language.

Machines in this generation are large and expensive (costing approximately hundreds of thousands of dollars).

In 1951 the UNIVAC (NIVersAl Computer) appears, it was the first commercial computer, which had a thousand words of central memory and could read magnetic tapes, it was used to process the 1950 census in the United States.

In the first two generations, entry units used punch cards, taken up by Herman Hollerith (1860 - 1929), who also founded a company that over time would become known as IBM (International Bussines Machines).

The IBM 701 was later developed by IBM, of which 18 units were delivered between 1953 and 1957.

Later, the Remington Rand company manufactured the 1103 model, which competed with the 701 in the scientific field, so the IBM developed the 702, which presented memory problems, due to this it did not last on the market.

The most successful first generation computer was the IBM 650, of which several hundred were produced. This computer used a secondary memory scheme called a magnetic drum, which is the ancestor of today's discs.

Other computer models that can be placed at the beginning of the second generation are: UNIVAC 80 and 90, IBM 704 and 709, Burroughs 220 and UNIVAC 1105.

Second generation

Around the 1960s, computers continued to evolve, reduced in size, and increased processing power. Also at this time began to define the way to communicate with computers, which was called system programming.

The characteristics of the second generation are as follows:

• They are built with transistor circuits. They are programmed in new languages ​​called high-level languages.

In this generation computers are reduced in size and are less expensive. Many companies appear and computers were quite advanced for their time like the Burroughs 5000 series and the ATLAS at the University of Manchester.

Some of these computers were programmed with punched tapes, and others by wiring on a board. The programs were custom tailored by a team of experts: analysts, designers, programmers, and operators who ran like an orchestra to solve problems and calculations requested by management. The end user of the information had no direct contact with the computers. This situation initially occurred in the first personal computers, since it was required to know how to "program" them (feed instructions) to obtain results; therefore its use was limited to those daring pioneers who liked to spend a good number of hours writing instructions, "running" the resulting program, and checking and correcting any errors or bugs that appeared. Also,in order not to lose the resulting "program" it was necessary to "save" it (store it) in an astte recorder, since at that time there were no floppy disks, much less hard disks for PCs; This procedure could take from 10 to 45 minutes, depending on the program. The panorama was totally modified with the appearance of personal computers with better circuits, more memory, flexible disk drives and above all with the appearance of general application programs where the user buys the program and gets to work. Word processing programs such as the famous Word Star, the impressive Visicalc spreadsheet and many more appear that change the image of the PC overnight. The sortware starts trying to catch up with the hardware. But here a new element appears: the user.

The computers of this generation were: the Philco 212 (this company withdrew from the market in 1964) and the UNIVAC M460, the Control Data Corporation model 1604, followed by the 3000 series, the IBM improved the 709 and released the 7090, The National Cash Register began producing commercial-grade data processing machines, introduced the NCR 315 model.

Third generation

With the progress of electronics and the advancement of communication with computers in the 1960s, the third generation of computers emerged. It opens with the IBM 360 in April 1964.3

The characteristics of this generation were as follows:

• Its electronic manufacturing is based on integrated circuits. Its management is through the control languages ​​of the operating systems.

IBM produces the 360 ​​series with the 20, 22, 30, 40, 50, 65, 67, 75, 85, 90, 195 models that used special processor techniques, nine-channel tape drives, magnetic disk packages, and others. features that are now standard (not all models used these techniques, it was divided by applications).

The 360 ​​series operating system, called OS which had various configurations, included a set of memory and processor management techniques that soon became standard.

In 1964 CDC introduced the 6000 series with the 6600 computer, which for some years was considered the fastest.

In the 1970s, IBM produced the 370 series (models 115, 125, 135, 145, 158, 168). UNIVAC competes with the 1108 and 1110 models, large-scale machines; while CDC produces its 7000 series with the 7600 model. These computers are characterized by being very powerful and fast.

At the end of this decade, the IBM 370 series produced the 3031, 3033, 4341 models. Burroughs with its 6000 series produced the advanced design 6500 and 6700 models, which were replaced by its 7000 series. Honey - Well participates with its computer DPS with various models.

In the mid-1970s, medium-sized computers, or minicomputers, appeared on the market that were not as expensive as large ones (also called mainframes, which also means, great system), but they had great processing capacity. Some minicomputers were the following: the PDP - 8 and PDP - 11 from Digital Equipment Corporation, the VAX (Virtual Address eXtended) from the same company, the NOVA and ECLIPSE models from Data General, the 3000 and 9000 series from Hewlett - Packard with several models 36 and 34, the Wang and Honey - Well-Bull, Siemens of German origin, the ICL made in England. In the Soviet Union the US (Unified System, Ryad) was used which has gone through several generations.

Fourth generation

Here are the microprocessors, which is a great advance of microelectronics, they are high-density integrated circuits and with an impressive speed. Microcomputers based on these circuits are extremely small and cheap, so their use extends to the industrial market. This is where personal computers are born, which have acquired enormous proportions and which have influenced society in general on the so-called «computer revolution».

In 1976 Steve Wozniak and Steve Jobs invented the first microcomputer for mass use and later formed the company known as Apple, which was the second largest company in the world, preceded only by IBM; and this in turn is still one of the five largest companies in the world.

In 1981, 800,000 personal computers were sold, the next it rose to 1,400,000. Between 1984 and 1987, around 60 million personal computers were sold, so there is no doubt that their impact and penetration have been enormous.

With the emergence of personal computers, the software and the systems that manage them have had a considerable advance, because they have made communication with the user more interactive. Other applications arise such as word processors, electronic spreadsheets, graphic packages, etc. Also, the industries of personal computer software are growing very rapidly. Gary Kildall and William Gates spent years creating operating systems and methods to achieve easy use of microcomputers (they are the creators of CP / M and Microsoft products).

Not everything is microcomputers, of course, minicomputers and large systems continue to develop. In fact, small machines far exceeded the capacity of large systems from 10 or 15 years ago, which required expensive and special installations, but it would be wrong to suppose that large computers have disappeared; on the contrary, their presence was already inescapable in practically all spheres of government, military and big industry control.

The huge CDC, CRAY, Hitachi or IBM series computers, for example, were capable of handling several hundred million operations per second.

Fifth generation

In view of the accelerated march of microelectronics, industrial society has set itself the task of putting the development of software and systems with which computers are operated at this point. International competition for dominance of the computer market arises, in which two leaders are emerging who, however, have not been able to reach the desired level: the ability to communicate with the computer in a more everyday language and not through specialized codes or control languages.

Japan launched the so-called "fifth generation computer program" in 1983, with the explicit objectives of producing machines with real innovations in the above criteria. And in the United States, an ongoing program that pursues similar objectives is already in operation, which can be summarized as follows:

• Parallel processing using special designs and architectures and high-speed circuits. Natural language management and artificial intelligence systems.

The foreseeable future of computing is very interesting, and it can be expected that this science will continue to receive priority attention from governments and from society as a whole.

TOPIC 2

ARCHITECTURE OF A COMPUTER

2.1 Hardware Concept.

We can call hardware the entire physical set of the computer, which includes the CPU (which contains all the processing cards, be they sound, graphics, modem, disk drives, processor, RAM, etc.), the monitor, speakers, scanner, printer, mouse, keyboard, microphone, among others. Hardware is the union of physical components capable of performing communication between the user and the software. (Analogously, the software or operating system is the translator between the machine and man, converting digital or analog signals into human language).

Every computer system has hardware components dedicated to these functions:

1. Input unit

2. Output unit

3. Central processing unit.

4. Memory and storage devices.

2.2 Central Processing Unit.

A central processing unit (CPU) is where data processing occurs. It is known as the brain of the computer. In microcomputers, the CPU is on a chip called a microprocessor. The CPU consists of two basic components: control unit and arithmetic and logic unit.

2.3 Control unit

The function of the control unit is to coordinate all the activities of the computer. All the resources of the computer are managed by the control unit. This unit contains instructions from the CPU to carry out commands.

In short, the control unit is the one that supervises, controls the other parts of the computer and regulates the work that must be carried out, that is, selects, verifies and interprets the instructions of the program and then verifies that they are executed.

2.4 Logical arithmetic unit - ALU

It is in the logical arithmetic unit (ALU) that the actual data processing occurs. All calculations and comparisons are performed and the results generated. When the control unit finds an arithmetic or logic instruction, it sends control to the logical arithmetic unit. The ALU contains memory built directly into the CPU that is used to store the data that is being processed by the current instruction.

2.5 Input unit

They are all the elements that allow the union of the user with the central processing unit and memory.: Among these we have.

Keyboard: Input devices that translate the data into a form that the computer can interpret, and then process and store it, there are forms: Alphanumeric keyboard and for perforation verification

Mouse and Joysticks: Devices that convert physical movement into binary electrical signals and that it be repeated on the monitor.

Image scanner or digitizer: They are designed to interpret characters, combinations of characters, graphic drawings written by hand or on machines or printers and translate them into the language that the computer understands.

Optical devices: among these we have, Brand reader or optical brand tracker, Image digitizer (scanner), Digital camera:

Audio digitizer: among these we have, Microphones

2.6 Output unit

These devices allow the user to view the results of computer calculations or data manipulations. The most common output device is the monitor, printer, modem.

Monitor: serves as an output device to receive messages from the computer.

Printer: secure A printer allows you to obtain a hard or physical copy of any information that may appear on the screen. There are two basic groups that are: Impact printer and no impact or page printer.

Modem: device used to link two computers transforming digital signals.

2.7 Concept of Memory

Memory is one of the most important parts of computers. Any user wants to add more memory to their computer. To define it, we will say that it is the ability of the PC to retain data or information permanently or temporarily. There are two types of memory, RAM and ROM, they are explained below:

2.8 Types of Memories.

ROM Memory (English Read Only Memory).

It is a read-only memory, smaller in size than the microprocessor. If you remove the protective layer from the integrated circuits, you will find information about the type of ROM memory, and the maximum size of information it can contain. The ROM BIOS (Basic Input / Output System) translates all commands into machine code, so that the computer can understand them.

2.9 Devices and Peripherals

Peripherals are external devices connected to the computer that allow it to receive input data, allow output information, and store data. They can be classified into three forms, input, storage, which are both input and output and finally output.

2.10 Storage device

It is any device that is used to record computer data permanently or temporarily. A disk drive, along with the discs it burns, is a storage device. Sometimes a computer is said to have primary (or primary) and secondary (or auxiliary) storage devices. When this distinction is made, the primary storage device is the computer's random access memory (RAM), a permanent storage device but whose content is temporary. Secondary storage includes the most permanent storage devices, such as disk and tape drives.

THEME 3

SOFTWARE

3.1 Software Concept

Software is a set of programs, documents, procedures, and routines associated with the operation of a computer system. Distinguishing itself from the physical components called hardware. Commonly, computer programs are called software; The software ensures that the program or system fully meets its objectives, operates efficiently, is properly documented, and simple enough to operate. It is simply the set of individual instructions that is provided to the microprocessor so that it can process the data and generate the expected results. The hardware alone cannot do anything, because it is necessary that the software exists, which is the set of instructions that make the hardware work.

3.2 Operating System

An Operating System is a program that acts as an intermediary between the user and the hardware of a computer and its purpose is to provide an environment in which the user can execute programs. The main objective of an Operating System is, then, to achieve that the Computer System is used comfortably, and the secondary objective is that the computer hardware is used efficiently.

3.3 Types of Operating Systems.

Currently operating systems are classified into three classifications: operating systems for their structure (internal vision), operating systems for the services they offer and operating systems for the way they offer their services (external vision).

Service Operating Systems (External Vision).

This classification is the most commonly used and known from the end user's point of view.

By Number of Users:

Single User Operating System.

Single-user operating systems are those that support a user at the same time, regardless of the number of processors that the computer has or the number of processes or tasks that the user can execute at the same instant of time. Personal computers have typically been classified in this line.

In other words, single-user systems are those that can only serve a single user, thanks to the limitations created by the hardware, the programs or the type of application that is running.

Multi-user Operating System.

Multi-user operating systems are capable of serving more than one user at a time, either through multiple terminals connected to the computer or through remote sessions on a communications network. It does not matter the number of processors on the machine or the number of processes that each user can run simultaneously.

In this category are all the systems that simultaneously meet the needs of two or more users, who share the same resources. This kind of system is used specially in networks. In other words, it consists of splitting time (timesharing).

By the Number of Tasks:

Monotarea Operating System.

Single task systems are those that only allow one task at a time per user. It can be the case of a multi-user and single-tasking system, in which several users are admitted at the same time but each one of them can be doing only one task at a time.

Single-tasking operating systems are more primitive and can only handle one process at a time or can only run tasks one at a time.

Multitasking Operating System.

A multitasking operating system is one that allows the user to be performing several tasks at the same time.

It is the operating mode available in some operating systems, through which a computer processes several tasks at the same time. There are several types of multitasking. Context switching is a very simple type of multitasking in which two or more applications are loaded at the same time, but only the application in the foreground (the one seen by the user) is being processed. In cooperative multitasking, which is used in the Macintosh operating system, background tasks receive processing time during the dead times of the foreground task, and whenever this application allows it. Timeshare multitasking, like OS / 2, each task receives the attention of the microprocessor for a fraction of a second.

A multitasking operating system may be editing a program's source code during debugging while compiling another program, while receiving email in a background process. It is common to find in them graphic interfaces oriented to the use of menus and the mouse, which allows a quick exchange between tasks for the user, improving their productivity.

A multitasking operating system is distinguished by its ability to support the concurrent execution of two or more active processes. Multitasking is generally implemented by keeping the code and data of various processes simultaneously in memory and multiplexing the processor and I / O devices between them.

Multitasking is often associated with hardware and software support for memory protection in order to prevent processes from corrupting the address space and behavior of other resident processes.

By the Number of Processors:

Uniprocess Operating System.

A single-threaded operating system is one that is capable of handling only one computer processor, so that if the computer had more than one it would be useless. The most typical example of this type of system is DOS and MacOS.

Multiprocessing Operating System.

A multithreaded operating system refers to the number of processors in the system, which is more than one and the system is capable of using all of them to distribute its workload. Generally these systems work in two ways: symmetrically or asymmetrically.

Asymmetric.

When working asymmetrically, the operating system selects one of the processors which will play the role of master processor and will serve as a pivot to distribute the load to the other processors, which are called slaves.

Symmetrical.

When working symmetrically, the processes or parts of them (threads) are sent interchangeably to any of the available processors, theoretically having a better distribution and workload balance under this scheme.

A thread is said to be the running, in-memory part of a process, which can consist of a memory area, a set of records with specific values, the stack, and other context values.

An important aspect to consider in these systems is how to create applications to take advantage of the various processors. There are applications that were made to run on single-process systems that take no advantage unless the operating system or compiler detects sections of parallelizable code, which are run at the same time on different processors. On the other hand, the programmer can modify its algorithms and take advantage of this facility by itself, but this last option is more often expensive in man hours and very tedious, forcing the programmer to take as much or more time to parallelization than elaborate the initial algorithm.

4. Operating Systems for its Structure (Internal Vision).

According to, two types of requirements must be observed when building an operating system, which are:

User requirements: Easy to use and learn system, safe, fast and suitable for the intended use.

Software requirements: Where aspects such as maintenance, mode of operation, use restrictions, efficiency, tolerance against errors and flexibility are included.

The different structures that present operating systems present to satisfy the needs that they want to obtain are described below.

Monolithic Structure. It is the structure of the first operating systems constituted fundamentally by a single program composed of a set of interlocking routines in such a way that each one can call any other. The fundamental characteristics of this type of structure are:

• Construction of the final program based on separately compiled modules that are joined through the linker. Good definition of link parameters between the different existing routines, which can cause a lot of coupling. They lack protections and privileges when entering routines that handle different aspects of computer resources such as memory, disk, etc.

3.4 Application Programs

Application programs are a set of programs that tell the computer how to analyze specific tasks for the user. The application is the object for which the computer is used. The computer obtains instructions from the application program. The application program is written by an application programmer, and it works under the direction of the computer's operating system.

3.5 Types of Application Programs

The application programs are divided into software packages (text editing, data storage and management, calculations, generating reports, communication with other computers, sending and receiving mail, etc.) and specific applications (billing, accounting, payroll, etc.).)

Examples of application programs:

• Word processor

Simplify the task of writing, editing, and printing a document. It also improves personal production by allowing you to duplicate a document without rewriting it, or retrieve the document without having to go through a ton of paper to find it. The user can see the letter on the screen, read it, correct it and change it before sending it to print. You can save the letter to disk and retrieve it later for minor changes, or use it again in the future. You can also collate and correct grammar and suggest synonyms. It saves a lot of time. Examples: Word, Wordperfect, Word Star.

• Spreadsheet

It is a spreadsheet that allows manipulation of data arranged in rows and columns. A cell can contain text, a number, or a formula that establishes a relationship with other cells. Every time a cell's content is changed, the spreadsheet frees you from the tedium of doing hand recalculations, saving a great deal of time. Types of applications: inventory, data recording, checkbook balancing, product planning, material and labor requirements, time report production, budget, real estate acquisition and search, real estate analysis, and marketing. Complex spreadsheet packages can make logic comparisons like "if-then-else" or "less than / greater than" tests. These operations are used in tasks such as payroll accounting. Examples: Excel, Lotus 123.

3.6 Programming Languages

Computers interpret (understand) a very simple language called machine language. Every machine language instruction is elementary. A program written in machine language needs many instructions to do simple things (that is, it is difficult to write) and only works on a computer of the same type.

High-level programming languages ​​are an evolutionary step and are intended to provide some level of computer abstraction and independence.

3.7 Programs

Computer programs are simple long lists of instructions for the computer to run, perhaps with data tables. Many computer programs contain millions of instructions, and many of those instructions are repeatedly executed. A typical modern PC (back in 2003) can execute around 2-3 trillion instructions per second. Computers do not take advantage of its extraordinary capabilities by the ability to execute complex instructions. Preferably, they make millions of simple instructions ordered by smart people, "programmers." Good programmers develop instruction sets to do common tasks (for example, draw a dot on the screen) and then you make those instruction sets available to other programmers.

THEME 4

4.1 Data storage

Storage units are peripheral devices of the system, which act as a support medium for the recording of user programs, and of the data and files that are handled by the applications that run on these systems.

The mass storage units that are the subject of this guide are used in all existing computing environments: centralized mainframe environments, distributed client-server environments, single-user desktop environments, single-user portable environments, etc.

4.2 Data and information concept

Fact

Minimum unit that composes any information.

information

Grouping of data with the aim of achieving a specific meaning beyond each of these. An example 2, 0, 0 and 1 are data; and 2001 is an information. Information has always been a very valuable resource, especially today even more so due to the development and expansion of Information and Communication Technologies.

4.3 Numerical Systems

Numbering systems are sets of digits used to represent quantities, so we have Decimal, Binary, Octal numbering systems. Hexadecimal, Roman, etc. The first four are characterized by having a base (number of different digits: ten, two, eight and sixteen respectively).

The binary numbering system is the most important in digital systems, in the decimal system the importance is that it is used universally to represent quantities outside of a digital system. This means that there will be situations in which decimal values ​​have to be converted to binary values ​​before they are entered into the digital system.

4.4 Concept of Bit, Byte and Fields.

Bit (Binary Digit)

Minimum information storage unit whose value can be 0 or 1; either true or false.

Byte

8-bit set which usually represents a value assigned to a character.

4.5 Concept of Registration

Processor registers are used to control running instructions, handle memory addressing, and provide arithmetic capacity. Registers are physical spaces within the microprocessor with a capacity of 4 bits up to 64 bits depending on the microprocessor used. The registers are addressable by means of a bullet, which is a memory address. The bits, for convenience, are numbered from right to left (15,14,13…. 3,2,1,0), the registers are divided into six groups which have a specific purpose

4.6 Concept of Files

Archives, whether general or historical, have the enormous task of storing and organizing vast amounts of information so that they can be retrieved by their potential users. Preservation and provision of services leads to the need for restoration and reprography. In the past, their nature as custodians forced them to work on technologies such as microfilm, which today are too expensive and limited. Currently, the digitization and organization of computerized information becomes an imperative. Fortunately, modern teleinformatics has opened up a great number of possibilities for the electronic management of files, to store and preserve information, to speed up and make efficient the search and retrieval of information, the management of indexes and facsimile images of documents.The physical limitations of old archives gives way to the concept of virtual archives that can provide secure, reliable and efficient services over the Internet, regardless of geographic considerations. Investigators and general users of files no longer have to physically move. Now the information is what travels to its users.

TOPIC 5

5.1 Introduction to operating systems

Since their creation, digital computers have used a system of coding instructions in a binary numbering system, that is, with the 0S. This is because integrated circuits work on this principle, that is, there is current or no current.

At the origin of the history of computers (about forty years ago), operating systems did not exist and the introduction of a program to be executed became an incredible effort that could only be carried out by very few experts. This made computers very complicated to use and required to have high technical knowledge to operate them. Its management was so complex that in some cases the result was disastrous.

Furthermore, the time required to introduce a program in those large, slow-processing machines far exceeded that of execution, and the use of computers to solve practical problems was of little use.

More elaborate means of manipulating the computer were sought, but which in turn simplified the work of the operator or user. It is then that the idea of ​​creating a means for the user to operate the computer with a well-defined environment, language and operation arises to make a true use and exploitation of it. Operating systems emerge.

An operating system is in charge of providing the user with a friendly and simple way to operate, interpret, encode and issue orders to the central processor so that it can perform the necessary and specific tasks to complete an order.

The operating system is the indispensable instrument to make the computer a useful object. Under this name are grouped all those programs that allow users to use this tangle of cables and circuits, which would otherwise be difficult to control. An operating system is defined as a set of manual and automatic procedures, which allow a group of users to share a computer installation efficiently.

Command Line Interface.

The form of interface between the operating system and the user in which the user writes the commands using a special command language. Systems with command line interfaces are considered more difficult to learn and use than systems with graphical interfaces. However, command-based systems are generally programmable, giving them flexibility that graphics-based systems lacking a programming interface do not have.

Graphical User Interface.

It is the type of display that allows the user to choose commands, start programs, and view lists of files and other options using the visuals (icons) and lists of menu items. Selections can be activated either through the keyboard or with the Mouse.

For application authors, graphical user interfaces offer an environment that handles communication with the computer. This allows the programmer to concentrate on the functionality, since he is not subject to the details of the visualization or the input through the mouse or keyboard. It also allows programmers to create programs that perform the most common tasks, such as saving a file, in the same way, because the interface provides standard control mechanisms such as windows and dialog boxes. Another advantage is that the applications written for a graphical user interface are independent of the devices: as the interface changes to allow the use of new input and output devices, such as a large screen monitor or an optical storage device,applications can use them without changes.

5.2 Functions of Operating Systems.

1. Interpret the commands that allow the user to communicate with the computer.

2. Coordinate and manipulate the computer hardware, such as memory, printers, disk drives, keyboard or Mouse.

3. Organize files on various storage devices, such as floppy disks, hard drives, compact disks, or magnetic tapes.

4. Manage hardware errors and data loss.

5. Serve as the basis for creating the software, making teams of different brands work in an analogous way, bridging the differences between them.

6. Set up the environment for using the software and peripherals; Depending on the type of machine used, the layout and characteristics of the equipment must be logically established. As for example, a microcomputer physically has two disk drives, it can simulate the use of other disk drives, which can be virtual using part of the main memory for this purpose. In case of being connected to a network, the operating system becomes the users' work platform and it is they who control the elements or resources they share. Similarly, it provides protection to the information it stores.

5.3 Category of Operating Systems.

Multitasking Operating System.

It is the operating mode available in some operating systems, through which a computer processes several tasks at the same time. There are several types of multitasking. Context switching is a very simple type of multitasking in which two or more applications are loaded at the same time, but only the application in the foreground (the one seen by the user) is being processed.). To activate another task that is in the background, the user must bring to the foreground the window or screen that contains that application. In cooperative multitasking, which is used in the Macintosh operating system, background tasks receive processing time during the dead times of the foreground task (for example,when this application is waiting for user information), and whenever this application allows it.

In timeshare multitasking systems, such as OS / 2, each task receives the attention of the microprocessor for a fraction of a second. To keep the system in order, each task receives a priority level or is processed in sequential order. Since the user's temporal sense is much slower than the computer's processing speed, timeshare multitasking operations appear to be simultaneous.

Monotareas Operating System.

Single-tasking operating systems are more primitive and the opposite of what was seen previously, that is, they can only handle one process at a time or it can only execute tasks one at a time. For example, when the computer is printing a document, it cannot start another process or respond to new instructions until printing is finished.

Single User Operating System.

Single-user systems are those that can only serve a single user, thanks to the limitations created by the hardware, the programs or the type of application that is running.

These types of systems are very simple, because all the input, output and control devices depend on the task being used, that is, the instructions given are immediately processed; since there is only one user. And they are mainly oriented by microcomputers.

Multi-user Operating System.

It is the opposite of single user; and in this category are all the systems that simultaneously meet the needs of two or more users, who share the same resources. This kind of system is used specially in networks.

In other words, it consists of splitting time (timesharing).

Batch Sequence.

Batch sequencing, or batch processing on microcomputers, is the execution of a list of operating system commands one after another without user intervention. On larger computers, the process of collecting programs and data sets from users, executing one or a few at a time, and delivering resources to users. Batch processing can also refer to the process of storing transactions for a certain amount of time before they are sent to a master file, usually a separate operation that takes place overnight.

The batch operating systems, in which the programs were treated by groups (batch) instead of individually. The function of these operating systems was to load a program on the tape into memory and run it. At the end this, the jump was made to a memory address from where it resumed control of the operating system that loaded the next program and executed it. In this way the time between one job and the other decreased considerably.

Real time.

A real-time operating system processes the instructions received instantly, and once they have been processed it displays the result. This type is related to single-user operating systems, since there is only one operator and you do not need to share the processor between multiple requests.

Its main characteristic is to give quick answers; for example, in a case of danger, immediate responses would be needed to avoid a catastrophe.

Shared time.

Computer or computer time sharing consists of the use of a system by more than one person at the same time. Timeshare runs separate programs concurrently, exchanging portions of time allocated to each program (user). In this regard, it is similar to the multitasking capability that is common to most microcomputers or microcomputers. However, timeshare is generally associated with multi-user access to larger computers and service organizations, while microcomputer-related multitasking involves multitasking by a single user.

5.4 The Most Popular Operating Systems on PCs.

The operating systems normally used are UNIX, Macintosh OS, MS-DOS, OS / 2, Windows 95 and Windows NT.

MS-DOS.

The meaning of these letters is Microsoft Disk Operating System. Microsoft is the name of the company that designed this operating system, and IBM the company that made it standard by adopting it in their microcomputers.

This operating system uses floppy disks with a specific organization. The discs can be recorded on one or two sides and the information is organized into 40 tracks of 8 or 9 sectors of a size of 512 characters, reserving the system for the disc's own information, which can be removable disc or hard disc. having in the second more capacity but similar structure.

The names of the files in MS-DOS, for which both letters and numbers are used, are made up of two parts: the file name and the extension, both data being separated by a period. The different disk drives are identified by MS-DOS through a letter followed by a colon. The most common extension types are how the memory loaded with them would appear; that is, they can load directly into memory without the help of the operating system.

Those with the.EXE extension require the DOS loader to put them in memory, which means that the operating system must be in memory. Those of type.BAT are command compounds that are executed sequentially.

The operating system has several components that are:

1. Control routines, which work with the IBM.DOS program, and are in charge of the input / output operations.

2. Command processor, also called COMMAND.COM, which processes the two types of commands available to DOS; that is, memory-resident or internal, and non-resident or external, residing on the operating system disk.

3. Routines of services accessible from the control program.

There is also the possibility of subdividing the disk into subdirectories that allow a more agile use of all the information.

MS-DOS is far from being the ideal operating system, since, at the moment, it is a single task system, but even if this were solved, it would still present design problems that cause the behavior of the machine to be unreliable. Despite these disadvantages and the fact that there are other operating systems in the world of microcomputing, you must always bear in mind the enormous amount of software that has been developed for DOS and that should be used as much as possible.

OS / 2.

Initially developed by Microsoft Corporation and International Business Machines (IBM), after Intel introduced its 80286 processor to the market. But the partnership did not last long as IBM viewed Windows as a threat to SO / 2.

But IBM continued to develop this operating system. OS / 2 was very similar to MS-DOS at the beginning, it has a command line, but the difference that exists with DOS is the command interpreter, which is a separate program from the operating system kernel and appears only when click on one of the "OS / 2 prompt" icons within the Workplace Shell. Another difference is that it does in a multitasking operating system.

In OS / 2 many of the commands are identical to those of its counterpart but it has more commands because it is bigger, more complete and modern.

The graphical environment is the Workplace Shell (WS), it is the equivalent of a workspace administrator for the WS.

Macintosh OS.

The operating system is the interface between the applications and the Macintosh hardware. The memory manager automatically obtains and releases memory for the applications and the operating system. This memory is normally found in an area called a cluster. An application's procedure code also takes up space in the cluster. Now a list of

the main components of the operating system.

1. The segment loader loads the programs to be executed. An application can be loaded in its entirety, or it can be divided into individual seconds that can be dynamically loaded as needed.

2. The event manager of the operating system reports the occurrence of various low-level events, such as pressing a mouse button or typing. Under normal conditions, the event manager in the toolbox passes these events to applications.

3. The file manager takes care of the input / output of files; device manager takes care of device input / output.

4. Device drivers are programs with which various types of devices can present uniform input / output interfaces to applications. Three device drivers are integrated into the ROM operating system: the disk driver is responsible for accessing information on disks, the sound driver controls the sound generators, and the serial driver sends and receives data through the ports. serial (thus establishing communication with serial peripheral devices such as printers and modems).

5. With the printer manager, applications can print data on various printers.

6. With the AppleTalk administrator, applications can transmit and receive information on an AppleTalk communication network.

7. The Vertical Layout Manager schedules the activities to be performed during vertical draw interrupts that occur 60 times every second when the video screen refreshes.

8. The system error handler takes over when a fatal system error occurs and displays an appropriate error box.

9. General operating system utility programs offer various useful functions such as obtaining date and time, character string comparison, and many more.

10. The starter pack is called by the standard file pack to start and name disks; it is most often applied when the user inserts a disk that has not been assigned initial values.

11. The Floating Point Arithmetic Package offers double precision arithmetic. The Transcendental Function Pack offers a random number generator, as well as trigonometric, logarithmic, exponential, and financial functions. Macintosh compilers automatically generate calls to these packages to perform numerical manipulations.

UNIX.

It is a multi-user operating system that incorporates multitasking. It was originally developed by Ken Thompson and Dennis Ritchie at AT&T Bell Labs in 1969 for use in mini computers. The UNIX operating system has several variants and is considered powerful, more portable and independent of specific equipment than other operating systems because it is written in the C language. UNIX is available in several forms, including AIX, a version of UNIX adapted by IBM (for use on RISC-based workstations), A / ux (graphical version for Apple Macintosh computers), and Mach (a rewritten but essentially UNIX-compliant operating system for NeXT computers).

UNIX and its clones allow multiple tasks and multiple users. Its file system provides a simple method of organizing files and allows file protection. However, the UNIX instructions are not intuitive.

This system offers a series of very interesting utilities, such as the following:

1. Inclusion of compilers and language interpreters.

2. Existence of user interface programs, such as windows, menus, etc.

3. Many facilities when it comes to file organization.

4. Inclusion of interrogation languages.

5. Graphic facilities.

6. Text editing programs.

SCO

SCO is the world's leading provider of operating systems for Unix servers, and one of the leading providers of client integration software that integrates Windows PCs and other clients with UNIX servers from leading manufacturers. SCO's business critical application servers run the critical day-to-day operations of a wide range of business, financial, telecommunications, and government organizations, as well as corporate departments and small and medium-sized businesses of all kinds. SCO sells and supports its products through a worldwide network of distributors, resellers, system integrators, and OEMs.

characteristics

1. Provides access to printers and shared files from PCs running Windows ® 95, Windows NT ™, Windows 3.1, Windows for Workgroups, OS / 2 ®, and MS-DOS ®

2. SCO TermLite, the terminal emulator, includes support for SCO ANSI and VT320 over TCP / IP or NetBEUI

3. Powerful and easy-to-use monitoring and network management tools along with other utilities can be accessed remotely

4. Includes the NetBEUI protocol layer for small networks; runs on SCO OpenServer Host Version 5 systems, as well as SCO OpenServer Enterprise Version 5 systems

5. The NT server tools allow the administration of shared resources on a server using UNIX system from a PC running Windows

6. Automatic configuration of connectivity layers, including NetBIOS over TCP / IP, and NetBEUI

7. Fully adhered to the emerging standard called CIFS.

Solaris

Features: Among the features of Solaris we have: PORTABILITY: The software made up of an ABI application of binary interfaces (Application Binary Interface) executes with a Shrink-wrapped (Shrink wrapped) the software on all systems sold with the same microprocessor architecture. This forces application developers to lower the cost of software development and bring products to market quickly, and forces users to upgrade hardware while retaining their software applications and minimizing their conversion costs. SCALABILITY: Applications are used more frequently over time, and require more powerful systems to support them. To operate in a growing environment,the software must be able to run over a powerful width range and must be able to take advantage of the extra power that is being processed. INTEROPERATIBITY: Computing the heterogeneous environment is a reality today. Users buy from many vendors to implement the solution they need. Standardization and a clear interface are criteria for a heterogeneous environment, allowing users to develop strategies to communicate through their network. The Solaris operating system can interoperate with some very popular systems on the market today, and applications running on UNIX can easily communicate. COMPATIBILITY: Computer technology continues to advance rapidly, but you need to stay competitive in order to minimize your costs and maximize your income.

Microsoft Windows NT.

Microsoft has been dedicated not only to writing software for desktop PCs but also to powerful workstations and network servers and databases.

The Microsoft Windows NT operating system, released on the market on May 24, 1993, is a network OS that provides power, speed and new features; in addition to traditional features. It is a 32-bit OS, and it can work on 386, 486 and Pentium processors.

In addition to being multi-tasking, multi-reading and multiprocessor, it offers a graphical interface. And it brings all the necessary software to work in networks, allowing you to be a client of the network or a server.

Microsoft Windows 95.

It is a multitasking environment equipped with a graphical user interface, which, unlike previous versions, Windows 95 does not need MS-DOS to be executed, since it is an operating system.

This OS is based on drop-down menus, on-screen windows and a pointing device called Mouse. One of the main characteristics of Windows 95 is that the names of the files are not restricted to eight characters and three of the extension, they can be up to 256 characters to have a complete description of the content of the file. It also has Plug and Play, a technology jointly developed by PC manufacturers, with which a user can easily install or connect devices allowing the system to automatically host hardware resources without user intervention.

Microsoft Windows 98

This Windows supports all types of Hardware, including the latest standards such as DVD-ROM and the ability to watch television on the PC.

It also offers plug and play features, which means that if you install a HARWARE plug and play device, such as an internal modem, it will work if your computer lacks the power, speed and memory to take advantage of its features.

Windows 98, the next step in the family of Windows desktop operating systems. In a way it is the continuation you could expect from Windows 95.

As it was obvious to predict, this new version continues to support 32 bits in its full dimension, although it is still necessary to wait for the full security functionality present in the 32 bits and that today is a characteristic of the NT family to be incorporated.

From the common user point of view, Windows 98 does not bring anything new.

Microsoft has not made relatively major changes to the interface, so if a user knows how to use Windows 95, they also know how to use Windows 98.

Windows 98: New version of Windows operating system. Arguably a compilation of features. Many of them were already in Internet Explorer 4.0 (when installed with the desktop update) in Windows 95 OSR-2.

Allows technical support for FAST32 (like Windows 95 ORS-2) and Active Desktop (from IE 4).

Windows 2000

Windows 2000 Professional is fast. Faster than Windows 98.

With 64 MB of memory, Windows 2000 runs an average of 25% faster than Windows 98.

And it doesn't slow down with heavy loads.

Users can run more programs and do more tasks at the same time because Windows 2000 is entirely based on a 32-bit architecture. By adding more memory, Windows 2000 gets even faster.

Supports up to 4GB of RAM and up to two symmetric processors. Unfortunately, achieving that level of performance with Windows 98, even with more memory, is impossible.

Improved interface

Windows 2000 Professional enhances the familiar Windows interface by reducing clutter on the desktop (eliminates unnecessary items), simplifying the start menu (introduces new smart functionality that adapts the start menu to your way of working, displaying only applications that you use most frequently).

Windows 2000 Professional works perfectly with your current computers. Your company's operating system infrastructure is very good, running on Windows 2000 Server, Windows NT Server, Novell NetWare, or UNIX.

Additionally, the built-in peer-to-peer resource sharing capability with Windows 9x and Windows NT Workstation enables Windows 2000 Professional to interoperate with earlier versions of Windows.

A more secure Windows system.

Windows 2000 Professional is very secure at all levels. Based on the security system integrated in all Windows NT operating systems, it allows users and administrators to select the appropriate level of protection for their information and applications, to exchange or store information on independent computers, on the network, on an intranet or In Internet.

With its Encrypted File System (EFS), Windows 2000 perfectly protects the data on your hard drive.

With support for Kerberos, Windows 2000 protects your corporate network or intranet. Kerberos protects data by tracking and verifying the activity of each user on a network.

Windows 2000 Professional protects even the most secret communications through a public network with its support for Public Keys, L2TP (Layer 2 Tunneling Protocol) and

Smartcards.

Smart cards are new devices that provide more security, because instead of relying on just one factor to authenticate a user, they ask for a combination of credentials (such as a username and password).

Simplified desktop management

Windows 2000 Professional makes life easier for administrators. Multiple wizards and problem detectors help end users perform routine or difficult tasks, reducing the time administrators have to spend helping them and reducing the number of calls to technical support.

Windows 2000 Professional gives administrators more control over individual desktops.

Windows 2000 offers unprecedented multilingual support, allowing users to create and view documents in the language used in nearly 120 international areas.

Windows Millenium

Windows supports me and shares the same code as Win98, which was an improvement to the Win95 operating system.

This will be sold as an OEM (Original equipment manufacturer) option, that is, presented on PC's.

Icons

MY PC: The icon has changed and also the way to see the hard drives, since they are now "under MY PC" in the tree shown by Windows Explorer.

RED environment is now> my RED sites.

SEARCH MENU : The interface has been modified to continue doing the same work, although in a friendlier way than before.

THE TASK BAR: apart from finding it in the start menu, we also find it in the control panel.

Now it allows us to configure all those old tricks with a single mouse click, for example:

1. Show context menu.

2. Move and resize the bar.

3. Scroll programs.

With WINDOWS MILLENIUN we can say goodbye to (MS-DOS), since the startup options "Command Prompt Only" and "Restart in MS-DOS mode" will not be available.

The configuration files "config.sys" and "autoexe.bat" do not run, whether they exist or not; they only make sense during Windows installation; later it will not matter its content.

(NOTE: Any MS-DOS program will not work, which needs to insert parameters in the CONFIG.SYS file. You should be aware that Windows Me Millenium Edition is no longer 100% compatible with applications designed for MS-DOS.)

System Restore

The system at our request creates «Checkpoints», depending on how we act:

• At the beginning of each day or from time to time Every time we install applications using setup, install and install (if it has another name, the System Restore does not work, so we could try renaming the installation file). The system will create a checkpoint before installing any new device that offers to: Install new drivers. Touch Windows settings.

And with a single click on "PC Restore", we recover the state of our PC at a specific day and time, thus avoiding reinstallations and wasted time, returning to the day when the PC was working 100%, just by pressing a button.

It will show us a calendar and within it, on each day, the points where we can recover the situation.

It should be noted that when restoring the system from a date prior to the current one, everything is restored as it was that day except the.doc,.bmp,.pdf files, email, browser history, Favorites and all the contents of the Folder My Documents, for which using this option will force us to be attentive to other content that you do not currently save in My Documents, so that you move them there.

This option consumes a lot of disk space (although we can configure all its options) but it will give us much more stability.

Windows Xp

This offers a reinforced Exit Menu. The output menu can now group your most frequent arrivals and applications.

Task Focus This plan allows you to view your Windows options as associated with your current task.

Scientific Search Buddy: Retrieve the search information for the task we are currently using.

This is new

Now you can:

1. Order prints directly from the Internet.

2. Link directly to the explorer's magician chambers.

3. Images of the view in Slideshow.

4. Post pictures to the Internet.

5. Company charts for easier e-mail distribution.

6. Perfect printing, painting and doing the best photo job.

You can also browse a single image from the Flastbed browser.

Updates Windows Downloaded, can also be applied to every user on a computer.

Windows update is now integrated with the help of and support center in Windows XP Home Edition. The appliance manager will also investigate Windows.

Internet Connection: protects your computer from instruction, when connected to the Internet. Now you can rest assured that Windows XP does not allow unwanted attacks on the Internet.

Thanks to the enhanced Windows 2000 engine, Windows XP takes on a new and improved look and extends the overall computing experience.

Windows XP presents a new image that will greatly facilitate its use by any type of PC user, improving its capabilities.

The new graphic design will make computing tasks easier, and will provide a new vision of the already known deskop, because it consists of the most significant update of the Windows interface since Windows 95.

A Windows XP Ready PC, you must meet the following hardware requirements:

1.- Pre-installed with Microsoft Windows 2000 Professional or Microsoft Windows Millennium Edition operating system.

2.- Displays of «Design 2000 for Windows» or the logo on the PC or notebook.

3.- Have a minimum of 128 MB of RAM

Windows XP, ready computers meet the minimum hardware requirements to run Windows XP Professional and Windows XP, Home Edition operating systems.

Hardware drivers, if necessary, are available from the original equipment manufacturer (OEM) in the Windows XP download.

Welcome / Login Screen: Windows makes it easy to create individual accounts for your computer users, which means that each time you log in you will have your own customized environment.

And if your family shares a computer, Windows XP allows you to go from one user to another quickly without the need to shut down or restart any program.

Start menu: The well-known Windows interface has been improved to make it even easier to use.

TOPIC 6

NETWORKS

6.1 Definition of Network

Data communication system that connects computer systems located more or less close to each other. It can be made up of different combinations of different types of networks

6.2 Types of Networks

LOCAL NETWORKS AREA (LAN)

Local type network that typically connects microcomputers, its amplitude does not go beyond a building.

METROPOLITAN AREA NETWORKS (MAN)

Network that typically connects different types of computers, its amplitude does not go beyond a city, municipality or a mixture of both.

WIDE AREA NETWORKS (WAN)

Network that typically connects different types of computers, its breadth goes beyond a city, municipality, country, continent. Example: World Wide Web

PRIVATE BRANCH EXCHANGE (PBX)

A network that typically connects a digital telephone line, to which computers can be connected using a digital / digital modem.

6.3 Elements of a network

A computer network consists of both hardware and software. Hardware includes: workstations, servers, network interface card, cabling, and connectivity equipment. The software contains the Network Operating System (NOS).

Work stations

Each computer connected to the network retains the ability to function independently, performing its own processes.

Servers

They are those computers capable of sharing their resources with others.

Network Interface Card

To communicate with the rest of the network, each computer must have a Network Interface Card (NIC) installed.

Cabling

The LAN must have a cabling system that connects the individual workstations to the file servers and other peripherals.

Connectivity equipment

In general, for small networks, the length of the cable is not limiting for its performance; but if the network grows, it may be necessary to extend the cable length further or exceed the specified number of nodes.

6.4 Client Server Architecture

It is a computational model in which the processing required to run a related application or set of applications is divided between two or more processes that cooperate with each other ». Usually most of the heavy lifting is done in the process called server and the client process (es) only deals with user interaction (although this may vary)

6.5 Communication protocols

Communication protocols allow machines located at different points to communicate. But in all this a problem arises, the incompatibility between different protocols prevented communication. That is why the OSI reference model was created:

It was proposed in 1983 by OSI (Organization Standart International), to try to standardize a set of protocols. The OSI model is not an architecture: it does not define the exact services and protocols for each tier, only what each tier must deal with.

TOPIC 7

INTERNET

7.1 Definition of the internet

The Internet is a computer network, it really is a set of computers connected to each other exchanging information.

The rapid and ascending growth of the Internet has made this network to be called "The Network" or "the network of networks", due to the existence of computers connected to it throughout the world.

The main difference between the Internet and any other computer network is that it does not belong to any country, or official body, or to a specific company, that is, it is a free network since anyone can access it from any point of the planet, in the same way that there is no type of restriction for all the information that circulates through it.

There are only a few international organizations spread all over the world and organized in a hierarchical way. These organizations do not have any profit motive, and are in charge of regulating the growth of the Internet and ensuring the proper functioning of the Network.

Probably the most striking feature of the Internet is that you can access any part of the world for the price of a local call, that is, the distance of it is not proportional to the cost of the established communication, this is because Each section of the network manages its own expenses and is not passed directly to the user.

7.2 Electronic Commerce

Electronic commerce can be defined, in a broad sense, as any form of transaction or exchange of commercial information based on the transmission of data over communication networks such as the Internet. In this sense, the concept of electronic commerce not only includes the electronic purchase and sale of goods, information or services, but also the use of the Internet for activities before or after the sale, such as:

• Advertising Search for information on products, suppliers, etc. Negotiation between buyer and seller on price, delivery conditions, etc. Customer service before and after the sale Comply with administrative procedures related to commercial activity

Collaboration between companies with common businesses (long term or only temporary) These activities do not necessarily have to be present in all e-commerce scenarios.

- In electronic commerce, companies, consumers and public administrations participate as main actors. Thus three basic types of electronic commerce are normally distinguished.

• Between companies or B2B (business to business) Between company and consumer or B2C (business to consumers) Between company and administration or B2A (business to administrations)

- Companies intervene as users (buyers or sellers) and as providers of tools or support services for electronic commerce: providers of public key certification services, financial institutions, etc.

For their part, public administrations act as regulators and promoters of electronic commerce and as users of it (for example, in public procurement procedures or purchases by the Administration).

- In a broad sense, consumers would participate in two additional forms of electronic commerce in addition to B2C: on the one hand, direct electronic commerce between consumers (direct sales between individuals) and, on the other, economic transactions between citizen and administration (payment social benefits, payment of taxes, etc.)

- The mention of Internet in the definition that opens this section is justified because, although electronic commerce activities between companies, for example through Electronic Document Interchange systems, have existed for more than a decade and predate commercial use. Internet, this openness to commercial use of the Internet, and in particular the development of the World Wide Web, has been the key element that has made it possible for electronic commerce to reach the final consumer and, ultimately, has caused the current explosive growth of the electronic commerce in all its forms.

CONCLUSION

• By doing this work we were able to understand the reason for things in the area of ​​computing, such as the interesting data from the history of the computer until the culmination with the Internet, which is a dream come true that so many people wanted to see and not For this reason, we thank God for living in this era and we hope that, like us, we appreciate the importance of computing for all people of this generation and those who will come to appreciate it.

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