What is the future in the new sector and what is the structure of the hard disk? How a computer's hard disk (HDD) is arranged The structure of a hard disk.

Like floppy disks, a hard disk is divided into tracks and sectors. Each track is uniquely identified by a head number and a serial number on the disc relative to the outer edge. Sectors are identified by their serial number relative to the beginning of the track. Sectors on a track are numbered from one, and heads and cylinders are numbered from zero.

The number of sectors can vary (from 17 to 150) depending on the type of drive. Each sector contains some service information and data. Typically, a sector is 571 bytes. At the beginning of each sector, a header (Prefix portion) is written, which identifies the beginning of the sector and its number, and at the end of the sector (Suffix portion) there is a checksum required to verify the data integrity. A 512-byte data area (for DOS) is located between the header and the end of the sector. The recording of information on the tracks is not carried out in a constant stream, as in household tape recorders, but in blocks of 512 bytes.

The number of disks, heads and tracks of the hard drive is set by the manufacturer, based on the properties and quality of the disks. These characteristics cannot be changed. The number of sectors on a disc depends on the recording method, and the density depends on the medium: the better the disc material, the denser data can be recorded on it. Modern hard drives contain up to 150 sectors per track.

Basic types of interfaces

The winchester must be connected via a controller, which can be located both on a special expansion card and on the motherboard itself. It is this controller that receives, transmits and processes signals from the hard drive. In practice, the most common hard drives are IDE, less often SCSI.

Let's take a closer look at these types of hard drives.

In IDE (Integrated Drive Electronics) hard drives, the control electronics are located not in the controller, but in the hard drive. The advantage of hard drives of this type manifests itself, first of all, when receiving and transmitting information, that is, in such hard drives, the reception and transmission of signals are optimally coordinated. These hard drives communicate with the controller with a 40-wire flat cable. IDE hard drives do not need to be low formatted. After installing it in the computer case and connecting it, all that remains is:

Write its parameters to CMOS Setup

Divide the hard drive into partitions and

Format it using the operating system

To compensate for different recording densities, the method of zone-section recording is used. The essence of the method lies in the fact that the entire working space of the magnetic disk is divided into zones: 8 or more. The lowest zone, that is, the track farthest from the center of the disk, contains more sectors (usually 120-96). Towards the center of the disk, the number of sectors decreases, reaching 64-56 in the oldest zone. As a result, since the disk rotates at a constant speed, much more information comes from the outer zones than from the inner ones. Uneven data flow is compensated for by increasing the speed of the readout / data conversion channel and using special tunable filters for frequency correction by zones, as well as by using high-performance single-chip microcontrollers.

Winchesters operating in this way cannot be declared in CMOS Setup with their actual parameters. For these discs, there is an option called Translation Mode. When it is installed, the value specified in CMOS Setup is recalculated by the controller in accordance with the arrangement of the cylinders and sectors.

LOGICAL STRUCTURE OF THE HARD DISK

In order to finally start working as an information warehouse, a hard drive must pass at least two tests: creating partitions and logical drives on your hard drive, and formatting.

Partitions and disks

Let's start with the first - breaking down a single hard disk space into smaller pieces. It is only for us, users, the hard drive looks like a monolithic creature, one and indivisible. Although, even from a physical point of view, this is not so: is the information space of our hard drive located on several physical plates? Now it turns out that at the logical level there can be several disks on one hard drive!

First of all, a disk can be partitioned into multiple partitions. For example, two - primary and secondary. The main program necessary for the computer to work (operating system) must necessarily reside in the main section (in practice, you can install SEVERAL operating systems on a computer).

But the fun begins next: in each section, we can create several more "logical drives"! At the same time, for us, users, and for the computer, they will look like separate devices, each of which will have its own name. It also happens vice versa - thanks to RAID technology, you can combine several physical "hard drives" into one logical disk. At home, this method is rarely used, but on powerful servers, busy, for example, with video processing or in computers - "libraries", such "superdisks" are found all the time.

In most cases, when a new hard disk is installed on a computer, only one partition is created on it and, accordingly, one logical disk. But many users believe that it is wiser to do otherwise for the correct organization of work. For example, if you have a large-capacity hard drive (from 100-200 GB) installed in your system, it can be split into at least two partitions. The first, with a volume of about 25–30 GB, can be reserved only for the operating system and application programs. And the second, larger section should be left at the mercy of documents, photographs, collections of music or films. Why is this needed? It's very simple: if something happens to the "system" section, your documents will remain intact in their "reservation".

Several logical drives will be useful to you even if you want to install several operating systems on your computer at once (for example, Windows and Linux). True, according to statistics, less than one percent of users are engaged in such tricks.

So, the hard disk is divided into partitions, logical disks are created in the partitions ... It is clear that each such disk should have a name - this is more convenient for both the user and the computer itself.

Drive names are letters, for example:

A - diskette;

C - hard drive;

D - second hard drive or, if not available, DVD drive ...

By the way, when you connect removable drives to your computer, for example, a flash drive or an external hard drive, the computer immediately allocates its own letter to them. And when you unplug the device and remove the disk from the system, the letter will be free. So, theoretically, you can easily create at least two dozen "logical drives" in a computer - letters would be enough. Although here it is important not to overdo it - what is the use of a dozen "virtual" disks, several gigabytes each!

For partitioning a hard disk into partitions, we can use both standard programs and separate utilities such as Partition Magic from Symantec.

Clusters and Sectors

So, we partitioned the disk into partitions and logical drives (or created one partition and a disk - it doesn't matter). So to speak, they divided the field into sections. But our work is not finished yet: after the breakdown we have to perform the formatting operation, logical marking of the entire hard drive space. This formatting is like plowing, transforming a formless space into a field ready for seeding, decorated with neat furrows.

However, the "furrows" have already been laid before us: at the physical level, the hard disk is already divided into tracks - which, in turn, are divided into sectors. Sector- This is the minimum physical disk space that can be occupied by data: as a rule, its volume is 512 bytes. This is quite a bit - imagine that you need to split a large file into pieces of 512 bytes, and even remember the location of each such grain! That is why, when logical partitioning of a hard disk, larger logical sections are created on it - clusters,combining several sectors. The number of sectors in a cluster, and therefore its size, depends on the size of the hard disk and the selected file system type.

For example, here is a table of cluster sizes for the NTFS file system:

The cluster size affects both the size of your files and the speed of the entire system. After all, nothing else can be put into a cluster partially occupied by a file. Let's say your file is located in 10 clusters of 1024 bytes in size, and in the last to tenth cluster it takes only ten bytes. What happens to the remaining free kilobyte? Nothing. It just disappears for you. Such unusable residues are called "tails". And in the "tails" quite often leaves a rather significant amount - up to several hundred megabytes!

If volume is more important to you, the cluster size should be as small as possible. But it is also impossible to reduce it to infinity: the smaller the cluster partition, the greater the fragmentation of data on your computer (which in turn leads to a decrease in the speed of data exchange with the hard disk).

The last stage of preparing a hard drive for work is creating file allocation tables(fat), a kind of table of contents that will list all your files and folders, as well as their physical addresses on your hard drive. However, it is worth talking in more detail about files and folders - "containers" in which all information on your computer is stored.

How information is stored?

Now, if asked how information is stored on your computer, you can answer like this:

Where exactly? - on the tracks and sectors of the hard disk (or, at the logical level - in the form of clusters on logical disks);

How exactly? - in the form of logical zeros and ones (bits), as well as their groups (bytes).

All this is correct ... But still it is not clear. It may be easier for a computer, because it is absolutely indifferent to what exactly we clog the hard drive with - whether with documents, music or pictures. For him, all this is information that needs only to be broken into certain pieces and at any time to know exactly where this or that piece is. But we users don't have to deal with bits and bytes. And even more so - not with clusters and sectors. We are interested in another division of information - logical. Substantial. Therefore, we need to accept a new unit, a new starting point. The file and the folder will become such units for us.

Files

File(file) translated from English is a sheet on which some information can be recorded. It doesn't matter if it is program code or text you created. Another thing is important - each such sheet is something logically complete, complete.

The file can store any information - text, graphic information, program code and so on (although there are some "combined" files, including, for example, a picture, text and program element). The main thing is that we, users, can always distinguish one "piece of information" from another and know exactly how we work with each type of file.

How it's done? It's very simple: each file, like a person, has its own "name" and "last name" (this is called the "type" of the file).

File namemost often it can be chosen arbitrarily by the user. Let's say you have created a document file with the text of your agreement with the company - it can be called "Agreement", "Document 4155" or in general "April Theses".

Previously, in the DOS era, file names could consist of a maximum of eight letters of the Latin alphabet - today there can be up to 256 of them and there are no language restrictions left. Working with the Russian version of Windows, we can give our document files Russian names, and the Chinese, for example, can easily use their hieroglyphs. Another question is that such a document cannot always be opened on other computers - "American" Windows may not understand the Chinese name, but our Russian version often stumbles over Western European symbols.

File typeshows what kind of filling is stored in each information "container" - be it a picture, text or program. The file type tells it expansion- a part of the name of three (rarely - of four) letters, separated from the main part of the name by a dot.

For example, the file that stores this workbook is called Compbook doc.

There are countless extensions in the computer world - remembering everything is simply unrealistic. However, there are not so many main extensions:

Ехе - denotes an "executable" file that stores the program. For example, winword exe;

Com is another type of program file. Usually com files correspond to small (up to hundreds of kilobytes) programs. They were often found in the DOS era, but today they have practically disappeared from the scene;

Bat is a so-called batch file designed for sequential launch of several programs (or commands). In fact, this is a regular text file, which contains the names of the program files that you want to execute, in the order you want.

Example: an autoexec bat file that is automatically executed when the computer boots up;

Cfg - configuration file, in which the program specifies the parameters of its work;

Dll is the so-called dynamically linking data library, which can be accessed by several programs as needed;

Hlp - a help file that stores "tips", and sometimes a complete manual for a particular program;

Txt, doc - text files;

Htm, html - Internet hypertext document;

Xls - spreadsheet;

Dat - data file;

Wav, mp3 - sound in digital format;

Bmp, jpg - graphic information, pictures;

Arj, zip, rar, 7z - files of "archives", that is, information compressed with the help of special programs - "archivers". A single archive file can actually contain many files. And so on.

Actually, you can write a whole book about file types (and such a book has been written for a long time, and more than one), but it is hardly necessary to list them all.

When working in Windows, you will most often see not the file extension, but the corresponding graphic icon. For example, a sheet with text and the letter W will show that in front of you is a document created in Microsoft Word. This, of course, is convenient, but just do not forget that the icons can change depending on which program is associated with this or that file type. In addition, one icon can indicate files of several types at once. Expansion in all cases remains unchanged.

The file also has one more feature called an attribute. However, unlike the name and extension (and in Windows - a certain type of icon), the user just does not see it. But the computer perfectly sees and understands. Here are just a few of these attributes.

Hidden(hidden). Files with these attributes are usually not visible to the user. For reinsurance, as a rule, these files are very important for the functioning of the system. Although an experienced "user" will not be difficult to configure the file viewer (file manager) in such a way that all hidden files will be visible at a glance.

Only for reading(read-only). But these files are always open to the curious eye ... But that's all. You cannot change their content - at least, without a special user command, so that the latter is completely sure of what exactly he is doing.

Systemic(system). This attribute, as a special distinction, marks the most important files in the operating system that are responsible for booting the computer. Their damage or removal always entails the most serious consequences, therefore a generous computer, without stint, "rewards" them at the same time with the two previous attributes - "read-only" and "hidden".

Archival(archive). This attribute is usually set when working with a file, when it changes. At the end of the session, it is usually removed.

Folders

If we compared files with leaves, then why don't we continue the analogy further? Where are the trees on which such useful leaves grow? The comparison with a tree is not accidental here. After all, the location of files on a hard disk is called a "tree structure". There are leaves. They grow on twigs. The twigs, in turn, grow on the branches. Branches ... Well, let's say, on branches. And the bitches ... And so on ad infinitum.

It is clear that you cannot keep completely different files in one heap. They need to be streamlined. Each cricket has its own six, each family has its own apartment ... And so on.

The files are grouped into special structures - folders. -Or - directories.Or - directories.Or - folders.It is completely incomprehensible why it was necessary to create such a bunch of terms for a single subject. Folder is the latest term and, in my opinion, the most successful one. It is in the folder that the leaflets-files lie. A folder that you can open at any time and find the desired sheet. A folder in which, by the way, you can attach another folder ...

Usually, each software package installed on your computer occupies its own, separate folder. However, it also happens that the program, like a sly cuckoo bird, scatters its files in many folders. This is especially liked by software packages that run under the Windows operating system.

How to distinguish a folder from a file? It's not that hard. Firstly, folders do not have an extension and are designated in Windows by special icons - just in the form of an opening folder. Second, editing operations cannot be applied to a folder. Rename, move, delete - please. And of course, you can open the folder to see what's in it. To do this, simply double-click on it with the left mouse button.

Well, now let's figure out what the logical address of any file or folder on our hard drive looks like. The first element of this address is the disk name. It consists of one letter, a colon and a backslash, called in computer jargon Back slash:

A: C: D:

Disk A:most often called a floppy drive, and until you insert a floppy disk into it, you will not have this disk. And God bless him: there are enough discs without him.

Drive C:- the main hard drive of your computer (or a logical drive in the main partition). It is from this disk that the system is loaded, it is on it that most of your programs and documents "live".

If your system has more than one hard drive or a single hard drive is divided into multiple partitions, these partitions will be named according to the following letters of the Latin alphabet. And the last letter is usually the CD-ROM drive.

Well, the third element of the address is the name of the file itself. For example, the address:

C: WINDOWS egedit exe corresponds to the program for editing the Windows registry, which is located on the C: drive in the Windows folder.

File system

Well, now you and I understand how it is more convenient for a computer to store data, and in what form we prefer to see it. There is only one thing left behind the scenes - how the sectors and clusters, crammed with bits and bytes to the eyeballs, turn into files and folders convenient for us! Mysticism, magic? Not at all. It's just that, talking about the logical structure of a hard disk, we deliberately skipped a very important step - creating file system. Namely, it allows us to finally organize the data on our hard disk and at any time to extract the desired piece from this information "trash heap".

When we write files and folders to the hard drive, the computer breaks them into clusters familiar to it and scatters them all over the hard disk space. The file, of course, does not fit in one cluster. He lives in several at once, and it is not at all necessary that these clusters will live side by side, like peas in a pod. More often it happens the other way around: the file is stored on the disk in a fragmented form - "head" in one part of the disk, "legs" in another ...

In order not to get lost in its own "bins", the computer creates at the very beginning of the hard disk a special "guide" to its contents - FAT, file allocation table. It is in FAT that all the information about which clusters a particular file or folder occupies, as well as their headers, are stored. This is convenient: with this method of placement, the computer does not have to frantically search on the hard disk for a piece of exactly the size that suits a particular file. Write where you like! And it becomes easier to delete files and folders - you do not need to erase the contents of the clusters belonging to them, you just need to declare them free by changing a couple of bytes in FAT. And the user still has the opportunity to quickly restore them using the same pair of bytes ...

File Allocation TableIs part of the file system, which is responsible for storing data on our computer. File systemis created on the hard disk at the final stage of formatting, and it is on it that such important parameters as the size of the cluster, the number (or type) of characters in the file name, the ability to work with folders depend, and much more - up to the maximum size of the hard disk ...

There are several standard file systems that are tied to specific operating systems.

For example, the ancient DOSand first versions of Windows used a 16-bit FAT16 file system, in which there was no support for long names, and the volume of a logical disk could not exceed 4 GB (65,524 clusters of 64 KB). In particular, it was this factor that forced the owners of large-capacity hard drives to “split” it into several partitions - otherwise it was impossible to work with the disk.

For Windows 95, a new modification of the file system was created - 32-bit FAT32, which allowed us to use the long names we loved so much. The maximum cluster size has been reduced to 16 kb (the standard size was 4 kb). And most importantly, the maximum hard disk size has increased - up to 4 TB!

However, it soon became clear that FAT32 also works flawlessly: despite the declared support for up to 4 TB of disk memory, standard utilities only allowed creating logical partitions up to 32 GB in size. In addition, the file size in FAT32 could not exceed 4 GB, which made it extremely difficult for fans of digital video (after all, a digitized film can take hundreds of gigabytes on disk!). So I had to think about changing the file system pretty soon, although today FAT32 is used, for example, when creating DVDs.

And seven years ago, the world slowly began to move to a new type of file system - NTFS, quantitative changes in which were much less interesting than qualitative ones. Yes, thanks to NTFS, it was possible to remove restrictions on the size of a file - now it can occupy at least the entire hard drive as a whole - and the maximum size of a disk partition has increased to 12 TB. However, the new features were much more interesting: in addition to the usual fixed-size logical drives, NTFS also allows you to create "dynamic" hard drives, supports encryption and password protection of individual partitions and folders.

The main quality of the new system is data storage reliability: if it was easier to "drop" a hard disk with FAT32, then under NTFS protection your data will feel much more confident. NTFS maintains its own "action log" to help protect data in the event of a failure.

Try suddenly shutting down your computer while copying or deleting a file in FAT32 - and, most likely, you will pay for such liberty with data loss. After all, changes in the file allocation table will not be saved, and your document will turn into a bunch of "lost clusters" (that's why FAT is always stored in 2 copies!). NTFS, on the other hand, makes changes to the table only when the operation is completed successfully, and the "journal" helps insure files against premature death.

Alas, for the sake of reliability, you have to sacrifice compatibility.

If hard drives formatted in FAT 16 and FAT32 can see almost all versions of Windows (as well as operating systems of the Linux family), then when using NTFS you are tightly tied to the Windows 2000 - XP - Vista line.

If two operating systems fit on your computer, the old Windows ME and the new Windows XP (with the NTFS file system), then the contents of the "ikspishny" partition or the whole disk will remain invisible to ME. Moreover, you lose the ability to work with the disk, booting in the "command line" mode from a CD or a "bootable" floppy disk - for DOS, the NTFS file system also does not exist.

Finally, if converting the FAT32 file system to NTFS is not difficult even with the help of standard Windows programs, and with full preservation of all information, then it is simply impossible to perform the reverse conversion in most cases without formatting the disk. And, as a result, the loss of all information ...

Of course, there are special programs for working with partitions and file systems, for example Partition Magic, which can convert an NTFS drive to FAT32 without losing information. But their use is fraught with difficulties - especially for beginners. ... And yet, despite all the shortcomings, using NTFS today offers far more advantages than inconveniences. Therefore, answer confidently: "Yes!" to the question of transferring to NTFS - and finally say goodbye to the past.

Programs and their types

Working with a computer, most people do not create the necessary programs on their own, but only use ready-made developments. That is why they are called users. However, being a user is not easy either. After all, it is necessary to be able not only to handle several common software packages, but also to navigate the "software sea" in order to easily and quickly find the necessary program in case of need and learn how to work with it.

List them all? But this is almost impossible: there are hundreds of thousands, if not millions of different programs, and about a hundred more are added every day! So is it worth trying to grasp the immensity? Therefore, we will try to split the entire array of programs created in the world into several main groups.

Types of programs by appointment

As you know, each program is responsible for its own, specific area of \u200b\u200bwork. Some help to create text or graphics, others - to put things in order on the hard disk, and others - to work on the Internet ... Sometimes it seems that how many programs - there can be so many categories. And this is partly true. However, with some diligence, you can try to reduce all of the software abundance to a few main sections. Let us indulge in the classification and we, having created a small "periodic table of programs" in the spirit of Mendeleev.

The first and most extensive group of programs that we will have to deal with are:

System programs.System - means that are necessary to ensure the normal operation of the computer, its maintenance and settings. These programs include primarily the operating system. And a number of auxiliary small programs - utilities.

operating system- it is the first and main intermediary between the computer "hardware" and all other programs, the soul and heart of the computer. There is no operating system - and your computer will not be able to accept any command, it will not even be able to boot.

Utilities.This class brings together a huge number of useful programs designed to maintain your computer. The choice of utilities must be approached especially carefully, so as not to overdo it. But you shouldn't miss anything really useful either - a properly selected utility can make your life much easier. This can also include tests - programs for testing both software and hardware resources of a PC.

Of course, it is unfair that the largest number of programs are created to serve the needs of a computer, and not of its owner - a person ... For us, the most important programs are creative, working tools designed to create and process information. In short, applied programs.

The user, unlike the computer, is an unusually whimsical creature. Therefore, there are much more types of application programs than system ones. Let's name just a few of them.

Office programs.The task of these programs is to create and edit documents, be it text, spreadsheet, image, or a combination of these. Sometimes such programs are called in the old fashioned way "editors" (although a person remains a real editor, and a program is only his working tool). Today, there are almost no separate programs of this class on the market - more often "complete sets" are sold, including everything you need. The most popular Microsoft Office suite consists of a Microsoft Word text editor, a Microsoft Excel spreadsheet, a Microsoft PowerPoint presentation program, a Microsoft Access database management program, and a number of smaller support programs. Stand apart financialand accounting software.Home bookkeeping has not yet become fashionable with us, but it's only a matter of time! In the West, programs for planning expenses, accounting for family finances and calculating taxes have always been among the most popular. This group includes spreadsheets and financial support utilities.

Multimedia programs."Media" in translation means - "carrier", "messenger", and in the modern interpretation - a type of information. Therefore, "multimedia" is a collection of all types of information. The term itself came into being in an era when the use of any informational means, in addition to "bare" text, was a wonder for a computer. Strictly speaking, only those programs that can work with several types of information can be called "multimedia". But there are not many such programs in nature ... And it just so happened that "multimedia" today are called graphic, sound, and video programs ... in short, those that work with a type of information other than text.

Programs for processing and creating images.

These are already quite professional programs, which should be installed on your computer only in one case, if you at least know how to draw. If not, then even such a powerful program as the editor of vector graphics (drawings) CorelDraw will not help you. The same applies to photo processing software such as Adobe Photoshop. Of course, with their help, you can create a magnificent photomontage or make fun of a photograph of your adored wife ... But, again, is it vital for you?

Programs for working with sound.The minimum set of programs for processing and playing sounds and music is already included in your operating system. A few additional programs (for example, players, or "players") will not hurt. And leave serious, professional packages for processing sounds (Sound Forge, CoolEdit) to professionals.

Turntables(players) and viewers (viewers), unlike editors, do not allow editing a text document, sound file or video. Their task is more modest, for example, to play a musical composition or display a picture on the screen.

3D graphics and animation editors.Thanks to Jurassic Park and other films stuffed with special effects, these programs have become surprisingly popular with us (although in the West, the same 3D Studio MAX or Softimage are purely professional programs worth tens of thousands of dollars).

Professional software.A very conditional group. Generally speaking, the program of any group can be classified as professional, highly specialized programs - it depends only on its "sophistication", the demand for a relatively small circle of people and, as a consequence, high prices. These programs have one thing in common: they are not suitable for the home office and for everyday use. And they are necessary for specialists who know why they, in fact, need this program. You can, of course, play around in 3D-Studio at home, but this is a thankless task. Of course, in addition to what is described here, there is also a sea of \u200b\u200b"specialized" programs, but, alas, it is impossible to write about all of them.

Programming tools.Super complex programming systems, professional compilers and much more. For programmers, this is the number one tool, but most often the home user does not need them. Although many modern programming systems are so simple and "visual" that they allow you to create applications by constructing them from ready-made blocks.

Computer-aided design systems (cad). These programs (for example, AutoCAD) are also often installed on home machines - out of ignorance, apparently, because drawing professional flowcharts is difficult and not like a game.

Mathematical and scientific programs- the domain of scientists and advanced engineers.

Commercial status of programs

In addition to the thematic division of programs, there is another classification. It is connected with the method of distribution of the program and those conditions, accepting which, the consumer gets the opportunity to use it. Well, and, of course, with its cost ... Every user knows that there are paid and free programs. But few people guess exactly how many modifications of "paid" and "free" were invented by the cunning authors of the programs!

Free software(freeware). Initially, small utilities or free add-ons to well-known commercial packages were distributed on the freeware principle. However, today, on the basis of freeware, quite serious packages of well-known manufacturers, including Microsoft, are sometimes distributed.

Freeware programs sometimes include applications that are distributed according to the principle of OpenSource (open source), for example, the Linux operating system and applications for it. However, this is not entirely true: the postulates of OpenSource imply the possibility of changing the program code by the user himself (which not all authors of freeware programs go to). And the distribution of such products does not have to be free - for example, there are many "commercial" versions of the same Linux in the world. More often than not, however, freeware and OpenSource go hand in hand.

Shareware- (shareware). The most massive group of programs, which includes almost all utilities, and often very serious, skillful software packages. As a rule, shareware-programs are distributed in the form of full-featured versions, limited either by the time of operation or by the number of starts. After the expiration of the period allotted to you for testing (usually from 15 to 45 days), the program either simply stops running or loses some of its functions, turning into a less functional freeware version. In the most favorable case for you, the program remains fully functional, but from time to time it annoys you with urgent calls to pay - this is what, for example, the popular file manager Windows Commander does.

If you still decide to purchase the program and transfer a certain amount to the author's account, then in exchange you will receive a special digital code (key), which must be entered into a special registration window of the program. As an option, a special "key" file can be sent, which must be copied to the folder with the installed program.

- The heyday of this type of programs came at the end of the 90s - today their popularity has dropped significantly. The adware principle implies that it is not the user who pays for the program, but the advertiser, who in return is given space to post information about their products in the form of banners or pop-up windows. And users are forced to watch this advertisement, and sometimes they also click on the pictures they especially like, going straight to the website of the advertiser ... The return on these trips is not very great, however, a couple of customers can bring, for example, hundreds of dollars in profit to an online store, 10 -15 of which he will willingly pay the programmer.

Unfortunately, software developers often abused this opportunity by introducing spyware and even viruses into their products, so that today adware programs are practically outlawed.

Commercial software(commercial ware). You always have to pay for these programs, and more often than not, quite significant amounts. This includes all major software packages from well-known manufacturers and a number of utilities. Programs of this type can be purchased in beautiful boxes or without them in any computer supermarket. However, today more and more software products are sold over the Internet. You can buy them either on the websites of software manufacturers, or in large online software stores. You can get the goods in two ways. Large programs in the form of those colorful boxes with a CD or documentation are delivered to your home by courier service or by mail, and small programs you can copy directly from the Internet site.

At the same time, as in the case of shareware-programs, you get a stripped-down (Demo)or limited in time (Trial)version. trial, like a shareware program, can be turned into a fully functional version by registering, but with a demo version, this trick will not work, since some functions are initially missing in it. For example, in a text or image editor, you cannot save your changes.

OEM versions.Special versions of common commercial software that come at a reduced price with off-the-shelf computers. For example, the cost of Windows in an OEM package can be several times cheaper than the "boxed" version.

"Shareware" programs(donation ware). The author of such a program hints that, in principle, he would not refuse a couple or two coins for his brainchild, but he does not force anyone to pay and does not limit the functionality of the program. If a desire appears - pay, it will not appear ... Well, no, there is no trial! It is clear that such "half altruists" among programmers are few. And there are even fewer honest payers among users.

"Postcard" versions(cardware). A very exotic kind of programs, as a reward for using which you are asked to send the author a beautiful postcard.

Software versions

As you know, programs are written by real people. And people have a habit of making mistakes. And errors occur in programs, perhaps, more often than in all other types of human activity combined. There are many reasons for this, but the main one is the complexity of modern computers: no one person can keep track of all the commands executed by a computer when a program is running - there are a lot of things involved. I'm not even talking about the wild variety of all kinds of hardware, settings and installed programs, which is encountered by the creation of any programmer that has been published. And, of course, you shouldn't forget about the programmer's own mistakes both in the algorithm and in its implementation ...

To understand where the implementation errors come from, you can take a typical example - division by zero. Let's say you decide to write a program that will calculate the average growth rate of a person (I don't know why, but let's say). The user enters his date of birth and his height, and the program subtracts the date of birth from today, calculates your age in days and divides the height by the number of your days. Such a program will work great for you and your relatives, but if you “release it to the people”, then there will certainly be someone who will enter today's number as a birthday. And it's done - the age is zero days, an attempt to divide by zero and the program crashes with an error.

This is of course the simplest example. In real life, everything is more complicated and depends not only on the data entered by the user (which you can, or rather, you need to check before using in the program), but also on the installed system files, drivers and a bunch of other things that are impossible to predict, and their impact on the performance of the program is not at all obvious.

As a rule, errors of the "first type" are calculated and corrected very easily, within 10 minutes. The "second type" is more complex, but affects a relatively small number of users. Usually, fixing such errors leads to a change in the second or third digit in the version number (or the author does not change the version at all, but simply uploads the updated file).

If you see that instead of version 2.1, say, 2.11 has appeared, then it makes sense to look at the program's website and see if a description of the changes has appeared there in order to understand whether you need it or not. Well, if the program is small, then you can just download the updated version ...

Another thing is introducing new functions into the program. After all, after the release of the program, the author receives a certain number of letters from users with requests to add or change something in the program, advice on improving it, and the like. If many people ask for one thing, then the author often listens to their opinion and adds the corresponding function. In addition, he himself can come up with something new and interesting and build it into the program. Typically, such changes lead to an increase in the second digit in the version number, that is, instead of 1.1, 1.2 appears.

Such updates are in most cases documented and described in the history txt or WhatsNew txt file. It is worth taking a closer look at such a version - there is a high probability that something appeared there that you were missing ...

The detected errors or suboptimal pieces in the program's algorithm, as a rule, turn out to be the most unpleasant for the author, since they require rewriting large pieces of code or even the entire program from scratch. At the same time, their correction is of the greatest benefit to those who use this program - the program's capabilities increase significantly, the speed of its operation, the appearance often changes, many new functions appear ... On the other hand, the data storage format may change, which will require some special actions when switching to a new version; the name of the program, its price and some other things may change that will require the user to carefully study the documentation (which, in general, never interferes). Such "global" changes usually lead to an increase in the first digit of the program version, that is, from 1x it turns into 2.0. Unfortunately, the rules for changing versions are not described or formalized anywhere; what I described is the "average description". Many authors use the release date of the program as the version number. Someone does not use "minor" versions at all, increasing the number by one for any smallest update. Someone changes the program without changing the version. Sometimes there are cases where the version changes, but there is no mention of the changes made. Everything is in the hands of the authors ...

Alpha(alpha) - very first version of the program, rough draft. The alpha status guarantees you that the downloaded program will be installed and even started, but its further actions are unpredictable. More often than not, the "alpha" version is crammed with errors, like a bun with raisins, many of its features and functions simply do not work. That is why alpha can only be used by the most impatient and desperate experimenters, thus fulfilling the role of testers. The rest should wait for the appearance of a more stable and reliable version - "beta".

Beta(beta) is already quite usable product. Gross errors were removed, the program performs basic tasks successfully. Only small imperfections remain, which may disappear in the next "beta". Many programs remain in beta status for most of their lives - remember, for example, the WinAmp player, The Bat! and a number of other programs, the "beta" nature of which does not prevent millions of users from using them.

After the bugs found in the alpha and beta versions of programs are fixed, and the functions are added, it is the turn RC (ReleaseCandidate)- candidate for the final version. This program is already considered stable and is used to identify the most hidden errors - such a program, almost without fear, can be downloaded and installed even by those users who are poorly versed in computers. And since they are in the majority, the number of users is increasing, which means an increase in the number of "testers". Errors in RC versions are calculated quite rarely, so when switching to the "main" version, the program practically does not change.

Finally, after all the torment and finishing touches, the light appears release(release) - completely finished, final version of the program.