Floppy disk capacity 3.5 inches. When and how floppy disks and disks appeared
The evolution of the modern floppy disk
Most of the technologies used in personal computers were developed either after the advent of PCs or specifically for them. One of the few exceptions is the floppy disk, also known as floppy disk, or floppy disk. Largely thanks to the floppy disk, the emergence of personal computers became possible, but it was thanks to personal computers that the floppy disk became so widespread. All information about capacities and formats below applies to IBM-compatible personal computers unless otherwise noted. This is explained by their significantly wider distribution, especially in Russia. Therefore, below you will not find descriptions of exotic floppy disk formats - may fans of the Macintosh or Amiga platforms not be offended by me.
The first floppy disk was developed by IBM in 1967. Thirty-two years is a very respectable age for computer technology, but, apparently, “my old lady is still alive.” Let's try to trace her life in development.
The time of birth of our heroine refers to the initial period of development of mini- and microcomputers. They required a storage medium that was different from the bulky storage devices used at that time on magnetic and punched tapes, hard drives and punched cards (cardboard cards with rows of numbers and a complex pattern of holes punched by a machine - something like brass disks for a mechanical piano. - Note ed.). The period of infancy and childhood, that is, the development of technology, took four years, so the first commercial drives were offered by IBM in 1971 - the same year that Intel introduced the 4004 processor. We can say that the two events coincided in time by chance, since There was no prior intention to use a floppy drive specifically on the future “Intel-compatible” personal computer. But this accident once again demonstrates the parallel development of various technologies that led to the emergence of the first personal computers.
The development of our heroine floppy disk in some ways corresponds to the stages of growing up of homo sapiens, and in some ways it is completely opposite to it. A person gains intelligence with age, his capabilities increase; The same can be said about floppy disks, the capacity of which increases as technology improves. But the “growth” of floppy disks has a completely opposite trend - it decreases with age.
Our heroine was born with a size (more precisely, diameter) of 8 inches (203.2 mm), which is not enough for a person, but for a medium with a capacity of just over 100 KB at that time it was just right. Named Flexible Disk at birth, it quickly received several slang names. For example, the “alias” floppy disk comes from the English word flop (“flapping wings”). Indeed, the sound produced when waving a 20x20 cm envelope is similar to the noise produced by a bird of the same size taking off. Such a medium began to be called a floppy disk a little later, after the first reduction in size. This is perhaps a record for the number of names for the same technology.
Initially, the floppy disk consisted of two parts: the media and the envelope. The media was a round plate with a central hole reinforced at the edges and one or more index holes cut from wide and thick double-sided magnetic tape. The envelope was made of plastic, smooth on the outside and covered with lint on the inside, and had holes for a spindle that rotated the media, a slot for heads and optocouplers for reading the index.
At the very beginning, the division of floppy disks into sectors was rigid, that is, each sector had its own index hole. Subsequently, the number of index holes was reduced to one, corresponding to the beginning of the track. Therefore, floppy disks of the Hard Sectored (hard sectored) and Soft Sectored (one index hole) types coexisted for some time. Due to internal reserves, the media volume was increased from 100 to 256 KB, which remained the physical limit for standard 8-inch floppy disks. Until the end of the 70s, floppy disk drives were installed mainly in mini-computers, and then in microcomputers (the PC we are used to belongs specifically to the class of microcomputers. - Note ed.). As a result, the production volume of floppy drives was small, and therefore their prices went through the roof for $1000.
The first mass-produced personal computer to use 8-inch floppy disks was the Apple II, demonstrated in prototype form in 1976. However, just a few months earlier, Shugart had announced a 5.25-inch floppy disk drive for a reasonable price of $390. However, 8-inch floppy disks were used for quite a long time, and drive designs shone with variety. For example, in the Rainbow personal computer (DEC), to reduce cost, the two devices shared a common head unit drive, so that only one floppy disk could be accessed at a time. By the way, on the issue of longevity. 8-inch floppy disks are still produced: those who don’t believe you can check the Imation website (http://www.imation.com, formerly a division of 3M).
So, in 1976, the first reduction in floppy disk size took place from 8 to 5.25 inches. Its volume briefly became 180 KB, which was clearly not enough, so floppy disks soon appeared, recording on both sides. They were called Double Density, although it was not the density that was increased, but the volume. These are the drives that were installed in the IBM PC personal computer, which was released in 1981.
As the volume of programs and data grew, it became clear that the capacity of a 360 KB floppy disk was clearly insufficient. A new format was developed and, accordingly, new floppy disks and drives. To manufacture 1.2 MB floppy disks, improved magnetic materials were used, which made it possible, while reducing the track width by half and increasing the recording density, to still obtain a satisfactory signal level from the reading head. Exactly doubling the number of tracks (from 48 to 96) made it possible to maintain backward compatibility, that is, a 1.2 MB floppy drive could read a 360 KB floppy disk. The floppy disk, interestingly, had no cutouts or holes through which the drive could determine its type; this information was recorded in the table of contents.
However, having reached a decent (and almost limiting for this technology) density, the 5.25-inch floppy disk still suffered from “childhood diseases,” that is, insufficient mechanical strength and the degree of protection of the media from external influences. Through the hole for the head unit, the surface could easily become dirty, especially if the floppy disk was not stored in an envelope. The floppy disk was literally flexible: it could be rolled up and... then thrown into the nearest trash can. Inscriptions on the sticker could only be made with a soft felt-tip pen, since a ballpoint pen or pencil would press through the envelope material. So the time has come for the soft floppy disk to acquire a hard shell.
In 1980, Sony demonstrated a new standard 3.5-inch floppy disk and drive. Now it has become difficult to call it flexible or floppy - “flapping”. The solid hard plastic housing and the absence of an index hole provide mechanical protection for the media. The only remaining hole, intended for access of the heads to the media, is covered with a spring-loaded metal curtain. To protect against accidental overwriting, there is not a sealed cutout, as on a 5.25-inch floppy disk (try to find the necessary piece of black sticky paper at the right time!), but a movable flap, which is part of the case design. Initially, the capacity of a 3.5-inch floppy disk was 720 KB (Double Density, DD), and then increased to 1.44 MB (High Density, HD).
It was just such a drive (and only one) that was installed in the computers of the sensational and rather disastrous series of IBM PS/2 computers due to incompatible innovations. Later, due to obvious advantages, this standard replaced 5.25-inch floppy disks. True, the more convenient Sony standard floppy disks in a hard plastic case were still inferior to “five-inch” diskettes in terms of price/capacity ratio, and the compatibility problem made itself felt for a long time: 3.5-inch disk drives could not be found everywhere.
The last evolutionary improvement of the floppy disk was undertaken by Toshiba in the late 80s. By improving media production technology and recording methods, the capacity of the floppy disk was doubled - to 2.88 MB. However, this format did not take root due to a number of reasons. The high transfer speed adopted in the drive of this format (more than 1 Mbit/s) was not supported by the majority of previously released controllers and chipsets designed for a speed of 500 Kbit/s, that is, to use the new drive it was necessary to purchase the appropriate card. The cost of such a floppy disk is high, amounting to several dollars compared to about 50 cents for a regular 1.44 MB floppy disk. And finally, the inertia of the huge mass of drives for 1.44 MB floppy disks, already available at that time, did not allow the market to swing towards 2.88 MB media - the use of a non-standard format could complicate exchange with the outside world.
Anatomy of a floppy disk
Like any other magnetic disk medium, a floppy disk is divided into concentrically arranged tracks. The tracks, in turn, are divided into sectors. Moving the head to access different tracks is done using a special head positioning drive, which radially moves the magnetic head assembly from one track to another. The various sectors within a track are accessed simply by rotating the media. Interestingly, the numbering of tracks begins with “0”, and sectors with “1”, and this system was subsequently transferred to hard drives.
The principle of recording information on a floppy disk is the same as in a tape recorder: there is direct mechanical contact of the head with a magnetic layer deposited on an artificial film - Mylar. This determines the low read/write speed (the media cannot move quickly relative to the head), low reliability and durability (after all, mechanical erasure and wear of the media occur). Unlike a tape recorder, recording is carried out without high-frequency bias - by reversing the magnetization of the carrier material until saturation.
As already noted, initially the marking of an 8-inch floppy disk into sectors was rigid, that is, the beginning of each sector corresponded to an index hole, the passage of which through the optocoupler caused an electrical impulse. This simplified the design of the controller (no need to track the beginning of each sector) and the drive (no need to maintain high rotation speed stability), but limited the increase in capacity due to internal reserves and reduced strength. Subsequently, thanks to the progress of microelectronics, the number of index holes was reduced to one, corresponding to the track header, and the sector headers were identified by the controller. In 3.5-inch floppy disks there is no index hole; synchronization is carried out solely by reading the headers.
At first, positioning of the head was most often carried out using the “stepper motor-screw-nut” mechanism. The head block was mounted on a carriage moving along guides parallel to the radius of the floppy disk. There was a hole in the carriage through which the screw passed, and on the hole there was a protrusion that fit into the thread on the screw and acted as a section of the thread of the nut. The stepper motor rotated the lead screw, moving the head block radially through the nut in one step per track. On an 8-inch floppy disk, only such a mechanism could ensure accurate positioning of the carriage with its large stroke (about 60 mm). After the advent of smaller flexible disks (5.25 and 3.5 inches), another kinematic head drive scheme was developed that is still in use today. It is based on a flexible, elastic metal strip, one end mounted on a carriage, and the other on a drum mounted on the shaft of a stepper motor. When the motor shaft (and drum) is turned, the strip is wound or unwinded, its other end moving the carriage with the block of heads translationally along the radius of the floppy disk.
The general design principles of the head block of classic floppy disks have undergone few changes. Their peculiarity is the presence of two tunnel erase heads located on the sides behind the recording/playback head. The role of these heads is to eliminate the interference of information recorded on adjacent tracks. Their work can be illustrated with the following example: one person sprinkles a path with sand, and two people following him sweep away all the sand that has fallen beyond the edges of the path.
The drives that are supposed to replace the classic floppy disk use even more complex heads that must interact with two different media, sometimes even based on different operating principles.
The floppy disk will still have time to catch a cold at the funeral of its “killers”
So, the evolutionary development of the floppy disk ended due to the fact that technology reached its limit. The period of revolutions has come, and, as with a political revolution, each revolutionary knows better than anyone what the “revolutionized” users need, and acts in accordance with this. The result is a variety of formats that differ from each other, so that the only real compatibility between all these devices is ensured by the fact that they can also work with a 1.44 MB floppy disk. The floppy disk “killers” line up: jostling with their elbows and getting in each other’s way. Let us list only the most “loud” names of these would-be killers:
- The LS-120 (Laser Servo) is the brainchild of Mitsubishi Electronics America and Winstation Systems, has a capacity of 120 MB and a maximum transfer speed of 4 MB/s (for the SCSI interface). Can also be connected via the IDE interface. Like Sony's new 200MB HiFD drive, this drive uses different heads to handle 1.44MB floppy and high-capacity media. To read/write media with a capacity of 120 MB, a magnetic head with a “laser sight” is used. That is, the head is positioned in a similar way to what happens in CD-ROM drives, but only along service tracks that are specially placed during the manufacture of the media and cannot be rewritten. The surface of an LS-120 floppy disk can accommodate 2,490 tracks per inch versus 135 tracks per inch for conventional 1.44 MB floppy disks. Analogous to the LS-120 in operating principle and volume, the SuperDisk Drive was developed by Imation (formerly a division of 3M).
- The floppy disk and HiFD (High Capacity Floppy Disk) drive were developed jointly by Sony, TEAC, Alps and Fuji. At a spindle speed of 3600 rpm, a transfer speed of about 600 KB/s is provided (according to other sources, Sony HiFD performance reaches 3.6 MB/s - testing in our laboratory will show. - Note ed.). The cartridge capacity is 200 MB.
- The UHC-31130 drive was invented by Mitsumi Electric and Swan Instruments.
- The Ultra High Density (UHD) drive from Caleb Technology Corp has a capacity of 144 MB. According to the developers, this IDE drive provides a sevenfold increase in performance compared to a traditional floppy drive. Caleb UHD has a stated data transfer speed of 970 KB/s, costs about $70, and in the future it is planned to increase the storage capacity to 540 MB.
- Samsung's Pro-FD has a capacity of 123 MB and a transfer speed of 625 KB/s. Positioning uses exclusively self-aligning magnetic technology.
The sheer abundance of technologies and formats gathered for the “funeral” of the floppy disk suggests that rumors of its death are greatly exaggerated. The reason for the wide popularity (maybe forced, since there is no and cannot be a replacement for it in the current situation) of the floppy disk is precisely that you don’t have to check the presence of a certain type of drive in the company where the data is sent: you don’t need to spend a lot of time checking with the secretary , do they have Zip or what kind of magneto-optics do they use. About 100 million 1.44MB floppy disk drives were sold last year, according to Disk/Trend.
The floppy drive not only did not die, but did not even weaken its position - in terms of unit sales, it is 12 times stronger than all its competitors combined, including Iomega Zip.
Therefore, my personal opinion is this: if anyone manages to bury the floppy disk, it won’t be all these “gravediggers” - they are more pushing each other away, trying to take possession of the inheritance of the person responsible for the event, than doing business. Moreover, they already have a competitor who has the main qualities of a floppy disk, namely: complete and absolute compatibility and mass availability. This means CD. As prices for rewritable and rewritable discs and related drives fall, they will become more common. Their main advantage is a head start from hundreds of millions of already installed drives and full compatibility with each other.
A standard floppy drive has a data transfer rate of 62 KB/s and an average seek time of 84 ms. This, along with the ISA bus (to which until recently 1.44 MB drives were connected), is a serious limitation on their performance. Even very slow (by the standards of high-density drives) LS-120 class drives have a seek time of about 70 ms, and data transfer speeds of up to 565 KB/s.
ComputerPress 8"1999
(MO), which were a hard polymer disk, read from which was carried out by a laser, and written using the combined influence of a laser (to heat a surface area) and a stationary magnet (to reversal the magnetization of the information layer). They are not completely magnetic, although they use cartridges shaped like floppy disks.
Story
3½″ floppy disk device
Iomega Zip
By the mid-90s, even a 2.88 MB floppy disk capacity was no longer enough. Several formats claimed to replace the 3.5″ floppy disk, among which Iomega Zip floppy disks gained the most popularity. Just like the 3.5″ floppy disk, the Iomega Zip media was a soft polymer disk coated with a ferromagnetic layer and enclosed in a hard case with a protective shutter. Unlike the 3.5″ floppy disk, the hole for the magnetic heads was located at the end of the case, and not on the side surface. There were Zip floppy disks of 100, 250, and by the end of the format - 750 MB. In addition to larger capacity, Zip drives provided more reliable data storage and faster read and write speeds than 3.5″. However, they were never able to supplant three-inch floppy disks due to the high price of both floppy drives and floppy disks, as well as due to an unpleasant feature of the drives, when a floppy disk with mechanical damage to the disk disables the disk drive, which, in turn, could damage the inserted then put a floppy disk into it.
Formats
| Format | Year of origin | Volume in kilobytes |
|---|---|---|
| 8" | 80 | |
| 8" | 256 | |
| 8" | 800 | |
| 8″ double density | 1000 | |
| 5¼″ | 110 | |
| 5¼″ double density | 360 | |
| 5¼″ quadruple density | 720 | |
| 5¼″ high density | 1200 | |
| 3″ | 360 | |
| 3″ double density | 720 | |
| 3½″ double density | 720 | |
| 2″ | 720 | |
| 3½″ high density | 1440 | |
| 3½″ extended density | 2880 |
It should be noted that the actual capacity of floppy disks depends on how they are formatted. Since, except for the earliest models, virtually all floppy disks do not contain rigidly formed tracks, the way was open for system programmers to experiment in the field of more efficient use of the floppy disk. The result was the emergence of many incompatible floppy disk formats, even under the same operating systems.
Floppy disk formats in IBM equipment
"Standard" IBM PC floppy disk formats differed in disk size, number of sectors per track, number of sides used (SS stands for single-sided floppy, DS for double-sided), and the type (recording density) of the drive - the drive type was labeled:
- SD (eng. Single Density, single density, first appeared in the IBM System 3740),
- DD (eng. Double Density, double density, first appeared in IBM System 34),
- QD (English: Quadruple Density, quadruple density, used in domestic clones of Robotron-1910 - 5¼″ floppy disk 720 K, Amstrad PC, Neuron I9.66 - 5¼″ floppy disk 640 K),
- HD (eng. High Density, high density, differed from QD in the increased number of sectors),
- ED (eng. Extra High Density, ultra-high density).
Additional (non-standard) tracks and sectors sometimes contained copy protection data for proprietary floppy disks. Standard programs such as diskcopy, these sectors were not transferred when copying.
| Magnetic coating parameter | 5¼″ | 3½″ | ||||
|---|---|---|---|---|---|---|
| Double Density (DD) | Quadruple Density (QD) | High Density (HD) | Double Density (DD) | High Density (HD) | Ultra High Density (ED) | |
| Base of the magnetic layer | Fe | Co | Co | |||
| Coercive force, | 300 | 300 | 600 | 600 | 720 | 750 |
| Magnetic layer thickness, microinch | 100 | 100 | 50 | 70 | 40 | 100 |
| Track width, mm | 0,300 | 0,155 | 0,115 | 0,115 | 0,115 | |
| Track Density Per Inch | 48 | 96 | 96 | 135 | 135 | 135 |
| Linear density | 5876 | 5876 | 9646 | 8717 | 17434 | 34868 |
| Capacity (after formatting) |
360 | 720 | 1200 (1213952) |
720 | 1440 (1457664) |
2880 |
| Disc diameter, ″ | 5¼″ | 3½″ | ||||||
|---|---|---|---|---|---|---|---|---|
| Disk capacity, KB | 1200 | 360 | 320 | 180 | 160 | 2 880 | 1 440 | 720 |
| Media description byte in MS-DOS | F9 16 | FD 16 | FF 16 | FC 16 | FE 16 | F0 16 | F0 16 | F9 16 |
| Number of sides (heads) | 2 | 2 | 2 | 1 | 1 | 2 | 2 | 2 |
| Number of tracks on each side | 80 | 40 | 40 | 40 | 40 | 80 | 80 | 80 |
| Number of sectors per track | 15 | 9 | 8 | 9 | 8 | 36 | 18 | 9 |
| Sector size, bytes | 512 | |||||||
| Number of sectors in a cluster | 1 | 2 | 2 | 1 | 1 | 2 | 1 | 2 |
| FAT length (in sectors) | 7 | 2 | 1 | 2 | 1 | 9 | 9 | 3 |
| FAT quantity | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| Length of the root directory in sectors | 14 | 7 | 7 | 4 | 4 | 15 | 14 | 7 |
| Maximum number of elements in the root directory | 224 | 112 | 112 | 64 | 64 | 240 | 224 | 112 |
| Total number of sectors on the disk | 2400 | 720 | 640 | 360 | 320 | 5 760 | 2 880 | 1 440 |
| Number of available sectors | 2371 | 708 | 630 | 351 | 313 | 5 726 | 2 847 | 1 426 |
| Number of available clusters | 2371 | 354 | 315 | 351 | 313 | 2 863 | 2 847 | 713 |
The first (more precisely, the 0th) is the lower head. Single-way drives actually use only the bottom head and replace the top head with a felt pad. At the same time, it was possible to use double-sided floppy disks on single-sided floppy drives by formatting each side separately and turning it over if necessary, but in order to take advantage of this opportunity, a second index window had to be cut in the plastic envelope of an 8-inch floppy disk, symmetrically to the first.
All floppy drives have a spindle speed of 300 rpm, except for the 5¼" high-density floppy drive, which has a spindle speed of 360 rpm.
Floppy disk formats in other foreign equipment
Additional confusion was caused by the fact that Apple used disk drives in its Macintosh computers that used a different principle of magnetic recording encoding than on the IBM PC - as a result, despite the use of identical floppy disks, transferring information between platforms on floppy disks was not possible until that time , when Apple introduced high-density SuperDrive drives that operated in both modes.
A fairly common modification of the format of 3½″ floppy disks is their formatting to 1.2 MB (with a reduced number of sectors). This feature can usually be enabled in the BIOS of modern computers. This use of 3½″ is typical for Japan and South Africa. As a side effect, activating this BIOS setting usually makes it possible to read floppies formatted with drivers like 800.com.
Features of using floppy disks in domestic technology
In addition to the above format variations, there were a number of improvements and deviations from the standard floppy disk format:
- for example, for RT-11 and its versions adapted in the USSR, the number of incompatible floppy disk formats in circulation exceeded a dozen. The most famous are those used in DVK MX, MY;
- 320/360 KB floppy disks Iskra-1030/Iskra-1031 are also known - in fact they were SS/QD floppy disks, but their boot sector was marked as DS/DD. As a result, the standard IBM PC disk drive could not read them without using special drivers (such as 800.com), and the Iskra-1030/Iskra-1031 disk drive, accordingly, could not read standard DS/DD floppy disks from the IBM PC;
- ZX-Spectrum platform computers used 5.25″ and 3.5″ floppy disks, but used their own unique TR-DOS format - 16 sectors per track, each sector 256 bytes (instead of 512 bytes standard for IBM PC). Both double-sided and single-sided floppy disks and floppy drives were supported. As a result, the data volume was 640 and 320 KB, respectively. The format supports only the root directory, which occupies only the first 8 sectors of the 0th track; the 9th sector contains system information about the floppy disk - type (TR-DOS or not), single or double-sided disk, total number of files and number of free sectors ( not bytes, but sectors). Sectors 10 to 16 on track 0 are not used. All files are located only sequentially - the TR-DOS format has no concept of fragmentation, and the maximum file size is 64 KB. After deleting a file inside the occupied space, free sectors appear that can no longer be occupied until the ″Move″ disk compaction command is executed. On IBM PC compatible computers, such floppy disks can only be read and written using special programs, for example ZX Spectrum Navigator v.1.14 or ZXDStudio.
In addition to the TR-DOS format, ZX-Spectrum compatible computers often used arbitrary disk formats. Some electronic magazines and games on the entire floppy disk used their own format, which was not compatible with anything at all. They could use sectors of 512 bytes, and even 1024 bytes, and often combined different sector sizes on one track, for example, 256 and 1024 bytes, and simply used different formats for different tracks. For example, this was done in the electronic magazine ZX-Format. Moreover, from issue to issue, this magazine constantly changed the format of the floppy disk tracks. This was done for two purposes: Firstly, to increase the amount of data on a floppy disk, and secondly, to protect floppy disks from pirated copying. Such floppy disks on ZX-Spectrum compatible user computers could only be read, run a magazine or game from them, but could not be copied with anything. To copy such floppy disks, for each individual issue of the ZX-Format magazine or game, it was necessary to write your own individual formatter and copier in assembler, having previously hacked the remaining stages of protection. Of course, such floppy disks cannot be read and copied on IBM PC compatible computers. Once I came across a completely unique format - except for the non-standard size of the sectors on the track (5 sectors of 1024 bytes each), the numbers of all 5 sectors were the same. To launch software from such a floppy disk, a special bootloader was used, located on the first track after the directory with the standard TR-DOS format for the ZX-Spectrum. In ZX-Spectrum compatible computers, both 5.25″ and 3.5″ floppy disks were used in the same way, the format did not depend on either the size of the floppy disk or the density it supported. But to use 3.5″ high-density HD floppy disks, it was necessary to seal the side density window with electrical tape. 5.25″ high-density HD floppy disks can be used in the ZX-Spectrum only if you use a drive that also supports HD density, but the drive must first be switched to the SD format (720 KB) using jumpers.
The pu_1700 driver also made it possible to provide formatting with shifting and interleaving of sectors - this accelerated sequential read-write operations, since the head was in front of the first sector when moving to the next cylinder. When using conventional formatting, when the first sector is always located behind the index hole (5¼″) or behind the area where the magnet attached to the motor (3½″) passes over the reed switch or Hall sensor, during the head step the beginning of the first sector manages to slip through, so the drive has to extra turnover.
Special BIOS expander drivers (800, pu_1700, vformat and a number of others) made it possible to format floppy disks with an arbitrary number of tracks and sectors. Since disk drives usually supported from one to four additional tracks, and also allowed, depending on design features, to format 1-4 sectors per track more than required by the standard, these drivers provided the appearance of such non-standard formats as 800 KB (80 tracks , 10 sectors), 840 KB (84 tracks, 10 sectors), etc. The maximum capacity consistently achieved by this method on 3½″ HD drives was 1700 KB. This technique was subsequently used in the DMF floppy disk formats
Floppy disks are a relic of the past for most computers used today, but for a long time they served as the only source of transferring information between computers. These disks are floppy disks that were labeled "3.5 [A] Disk" in Windows. This device can still be found on old computers.
History of floppies
The spread of floppy disks began when A. Shugart from IBM invented them. At first, this device was huge - about 8 inches (more than 20 cm). Almost immediately, synonyms for this name appeared, such as “floppy disk”, “floppy disk”. The latter name appeared later, when floppies became smaller in size and reached 5.25 inches. At this time, their capacity was 360 kilobytes, which today is even difficult to imagine, since today the smallest files are measured in megabytes.
By the mid-80s of the last century, the floppy disk size was 3.5 inches. This floppy disk existed until the final transition to various disks and flash drives occurred.
The capacity of floppy disks could vary, since the standard capacity was installed on an unformatted floppy disk, and different formatting methods were used. In this regard, formats appeared that were incompatible with each other. The Macintosh company used diskette drives with a different recording encoding principle compared to IBM, which did not allow information on floppy disks to be transferred between different operating systems until Apple created diskette drives SuperDrive, which worked in two modes.
Floppy disk device
Information is recorded on a thin plastic disk, which is protected on top by hard plastic, which has an open area on top, closed by a special curtain, usually metal. Under the hard plastic was an anti-dust cloth. The disk underneath is coated with ferromagnetic material. By analogy with a hard drive, it is divided into tracks and sectors. A floppy disk has two surfaces on which recording can be done simultaneously (although there were also single-sided floppy disks, marked SS), since the magnetic heads are placed offset relative to each other, and therefore no interference is created during recording. The disk begins to move when the motor engages with the center of the disk, made of metal. Depending on where the recording is going, it makes 300-360 revolutions per minute.
The floppy disk had a plug that allowed or prohibited writing to the floppy disk.
Floppy disk formats
The most common floppy disk formats differed in the number of sides used, recording density, number of sectors per track, and disk size. The drive could have single (SD), double (DD) or quarter density (QD) (this density was used in clones with 5.25-inch floppy disks of 640 and 720 kilobytes in size), as well as high density (HD), which differed from the previous one an increased number of sectors, extended density (ED), in which floppy disks had 36 sectors (standard - 18 sectors) and a volume of 2880 kilobytes, but there were many negative reviews, and therefore they were not widespread.
5.25 and 8" floppy disks could have a capacity of 160 to 180 kilobytes. 8" floppy disks had only one side for recording. 5.25" floppy disks for DD drives already had a capacity of 320-360 kilobytes, which is 3. The 5-inch floppy disk increased to 720 kilobytes (SD and QD were absent for the 3.5-inch floppy disk), the QD for 5.25" had a volume of 640-720 kilobytes, the HD 3.5" had 1440 kilobytes, 5.25" - 1200 kilobytes.
There were deviations from these standards, for example, for the Iskra-1030 (1031) computers, 320/360 kB floppy disks were used, which were actually SS/QD, but their boot sector was marked as DS/DD, which led to the IBM floppy drive The PC could not read them, just like the disk drive of these computers could not read the IBM PC floppy disks.
Advantages of a floppy disk
- Recording is carried out using a simple algorithm.
- Low cost.
- Affordability and versatility (in recent times, all computers were equipped with a floppy drive).
- The optimal volume for that time for transferring information between computers not connected to a network.
- Rewritability.
Disadvantages of floppies
- While the volume was optimal for transferring text files, spreadsheets, it was small for photographs, pictures, the capacity of the floppy disk (1.44 megabytes) was poorly suited for transferring software, especially when its size became alarmingly fast. grow.
- Constant creaking when recording.
- Slow recording speed.
- Unreliability (if one sector is damaged, the entire disk could become unreadable).
- Short service life (usually after several uses the disk was damaged, largely due to the fact that the plastic surface did not protect it reliably).
These shortcomings led to the fact that most users left negative reviews about floppy disks, which gradually led to the creation of new storage media and the disappearance of floppy disks.
Disconnecting the floppy disk
Typically, this type of safe ejection of the floppy disk is not required. There is a button on the floppy disk drive, with which the floppy disk was removed after the end of the noise it produced, which indicated the end of recording.
In this case, the question of how to disable a floppy disk can be considered in relation to the computer's BIOS. So, by going into the BIOS and going to its Standard CMOS Features section, you can see, depending on the type of floppy disk used, the designation Drive A or Drive B; opposite, information about the capacity and size is indicated. If you need to disable it, you need to press the “+” button until the word None appears instead of capacity and size, after which you need to press F10 to save the changes and reboot.
Floppy emulators
The appearance of these programs was due to the fact that floppy disk drives began to gradually disappear from computers, while some programs required a floppy disk to write files. Some accounting programs refused to save the file anywhere except to a floppy disk.
One of the most common emulator programs was the Virtual Floppy Drive program, which provided full integration of the drive, which was virtual, with the Windows operating system up to its version of Vista, while it was possible to create virtual floppy disks on which the necessary information could be placed, and support was provided virtual 3.5" and 5.25" floppy disks with support for capacities from 160 kB to 2.88 MB. These floppy disks could be formatted and also, which was important for that time, run in console form.
There were many such floppy disk emulators released, but all of them were characterized by approximately the same algorithm of operation.
Disappearance of floppy disks
The edges of the casing covering the plastic disk periodically bent, causing the floppy disk to get stuck in the drive; the spring, which was supposed to return the casing to its original state, could move, which led to the fact that the floppy disk was not closed by the casing as it should have been be closed. When a floppy disk was dropped on the floor, the disk often failed. All this needed improvement.
But new times have come with new technologies. Recordable and rewritable CDs first appeared, then DVDs, etc., then flash media appeared, which had a lower cost per unit of capacity, greater durability, and a greater number of rewrite cycles. All this led to the fact that new computers increasingly lacked floppy drives, and gradually floppy disks practically disappeared from our everyday life.
Cinquefoil bush Floppy Disk
With the almost complete disappearance of floppy disks in today's life, their name has not disappeared. Floppy Disk can be used as a low hedge, on rocky terraces, along with shrubs and trees, rock gardens and as a border. It has bright pink semi-double flowers with yellowness in the middle on a bush up to 40 cm high. This shrub loves light and tolerates frosts and winters well.
Finally
Floppy disks were portable data storage used when there was no network between computers and for some programs that automatically saved data to a floppy disk. Later, floppy disk emulators began to be used for such programs. Floppy disks developed extremely slowly, their design and capacity were imperfect, which contributed to their extinction. But the name "Floppy Disk" was left in the name of one of the decorative cinquefoils.
One of the oldest devices for storing information on a personal computer is a floppy disk drive, or FDD (Floppy Disk Drive) for short. This device, widely used during the 1970s-2000s, is now rarely seen in modern computers. However, in some cases you can still see a floppy drive installed in an old PC. In addition, external floppy drives are sometimes used, connected to the computer through I/O ports.
The first floppy disk drive and floppy disk were 8 inches wide and were invented by engineer Alan Shugart, who worked at IBM, in the early 1970s. In the mid-1970s, he also developed a 5.25-inch floppy disk and a drive for reading it. In 1981, Sony developed a floppy disk and a 3.5-inch drive. Initially, the capacity of such a floppy disk was 720 KB, but later its capacity was doubled.
Repeated attempts have been made to improve floppy disks based on the 3.5-inch format. For example, in 1987, a 2.88 MB floppy disk drive was developed, and in the late 1990s. – LS-120 standard with an even larger disk capacity of 120 MB. However, all these modifications have not become widespread, largely due to the high cost of drives and media.
Principle of operation
FDDs operate in many ways similar to hard drives. Inside a floppy disk, just like inside a hard drive, there is a flat disk with a magnetic layer applied to it, and information from the disk is read using a magnetic head. However, there are also differences. First of all, a floppy disk is not made of a hard material, but of a flexible polymer film, similar to magnetic tape. That is why disks of this type are called flexible. In addition, the floppy disk does not rotate constantly, but only when a request is received from the operating system to read information.
The advantage of FDD over a hard drive is media removability. However, floppy drive also has many disadvantages. In addition to the extremely low operating speed, this is also low reliability of information storage, as well as low storage capacity - approximately 1.44 MB for 3.5-inch floppy disks. True, when using non-standard formatting methods, the capacity of a floppy disk can be slightly increased, but, as a rule, this leads to an even greater decrease in recording reliability.
Varieties
Personal computers such as the IBM PC used two main types of FDD - 5.25-inch and 3.5-inch. Both types of drives are designed to accommodate floppy disks of different types and sizes and are incompatible with each other. This situation is different from that of optical drives, which can read both 3.5-inch and 5.25-inch disks. At one time there were also 8-inch FDDs, but already in the 80s. Such drives have fallen out of use. Around the 1990s. 5.25-inch drives have also finally gone out of use. 3.5-inch floppy drives lasted longer, until the end of the 2000s, and even now you can occasionally see them here and there.
Comparative sizes of internal 8, 5.25, and 3.5-inch drives
Examples of Floppy drives in order of priority: 8-inch, 5.25-inch and 3.5-inch
The 5.25-inch floppy disk is a disk in a cardboard case, reminiscent of an envelope, and has a slot for the read head. Such a floppy disk fully justifies its name “flexible”, since its body can be bent by hand without much effort. However, it is not recommended to intentionally bend the floppy disk too much, as this will almost inevitably lead to its failure.
The 3.5-inch floppy disk does not have this drawback. It has a magnetic disk enclosed in a hard plastic case and bending it with your hands is not so easy. In addition, the 3.5-inch floppy disk has a special metal curtain that hides the slot for the read head. Another feature of a floppy disk is the presence of a switch that blocks writing to the disk. A standard 3.5-inch floppy disk has a capacity of 1.44 MB, which is larger than the maximum capacity of a 5.25-inch floppy disk, which is 1.2 MB.
Examples of floppies are from left to right 8, 5.25, and 3.5.
The design of the 3.5" FDD is also different from the 5.25" one. If, when inserting a floppy disk into the slot of a 5.25-inch drive, the user needs to fix the floppy disk by turning the lever, then the 3.5-inch diskette is locked in the drive automatically, and the floppy disk is ejected back using a special button.
As with many other drives, there are mobile versions of floppy drives - external floppy drives. An external floppy drive is convenient because it does not take up space in the system unit, especially if the need to use floppy disks arises rarely. Such an FDD drive can be connected to a PC using a USB connector or an LPT connector.
Application
Although hard drives appeared in the first IBM-compatible personal computers, nevertheless, not a single computer could do without a device for removable drives. A similar device was the floppy drive, which quickly gained popularity due to the simplicity and low cost of both the drive itself and the storage media - floppy disks.
However, in some cases, a floppy drive could completely replace a hard drive. When the author of these lines got his first IBM-compatible computer, it did not have a hard drive, much less an optical drive, but only a 3.5-inch floppy drive and a set of floppy disks with software provided by the PC seller. The computer was fully functional. Of course, there was no talk of using Windows 3, or of running any large programs, but when using MS-DOS it was possible to deal with most of the programs and games existing at that time (early 90s). This suggests that floppy disks are capable of satisfying the user's basic information storage needs. In addition, floppy disks were once indispensable when it was necessary to reboot the computer for a maintenance check or install a new OS.
Setting up a floppy drive in the BIOS
There are several options in the BIOS that allow you to configure floppy drive settings. For example, the option allows you to disable the floppy drive controller if it is not used in the system, thereby freeing one system interrupt. Also, in some BIOSes, you can manually set the type and size of the drive media, as well as set the write ban on floppy disks.
Conclusion
Today, many users may not even know what a floppy drive or even a regular floppy disk looks like. Their functions were taken over by memory cards and flash drives. In most system units, the only reminder of a floppy drive is the 3-inch external bay left for them, and in Windows operating systems, the unused first letters of logical drives (A and B), reserved for floppy drives. However, floppy disk drives are often found in older computers. In addition, floppy drives can be useful when booting a PC for the purpose of carrying out preventative maintenance of the computer or when installing an OS.
Despite the end of the floppy disk era, 3.5 floppy disks are still used in everyday life.
Let's take a closer look at where they can be found, what's special about them and why the floppy disk is still one of the most popular means of transmitting secret information.
Contents:
Basic concepts and history of use
Floppy disk is a physical storage medium with which data can be moved, erased, or rewritten many times.
In simple words, this is a simplified version of modern flash drives and disk drives.
The floppy disk was the first to appear.
Externally, the device has a rectangular shape and a plastic case. A ferrimagnetic layer is applied on top, with the help of which the floppy drive reads information. You can't read a floppy disk using . To do this you will need a special floppy drive.
Today it can only be found in older desktop computers. Typically the drive is located at the bottom of the case and has the following form:
The first floppy disk was created in 1967 by Alan Shugart- at that time one of the leading specialists at IBM. Before 1076, Shugart created and developed his own company, which began supplying storage drives to computer system developers. This began the era of using floppy disks. The most popular floppy disk format was developed by Sony in 1981. A drive with a diameter of 3.5 inches can still be found in stores. Also, it is this type of floppy disk that is recognizable. In most programs, a key with a 3.5-inch floppy disk icon means saving actions.
Floppy disks were common among users from the 70s to the 90s of the last century.
With the invention of optical disks, the popularity of floppy disks gradually began to decline. As you know, optical discs are already being removed from use today.
Many manufacturers of laptops and personal computers have completely abandoned the use of disk drives.
Despite this, floppy disks are still produced and sold.
With the onset of the 2010s, all global IT corporations began to abandon the production of floppy disks.
For example, in 2011 Sony announced that it would completely stop creating and selling 3.5-inch floppy disks.
Now they can only be manufactured by order of the government.
Other cases of failure of floppy disks:
- year 2014– Toshiba announced the closure of its disk manufacturing plant. That same year, the plant was converted into a huge organic vegetable farm;
- 2015– developers from Microsoft decided not to create support for floppy disks in . This OS does not work with floppy disks and it will be impossible to connect an external drive. The system simply “will not see” the device;
- 2016- The Pentagon drew up a modernization plan, one of the goals of which was to abandon the use of floppy disks. The plan is scheduled to be completed by the end of 2018.
Floppy disk formats
Types of floppy disks are divided depending on the diameter of the drive. Over the entire period of floppy disk distribution The following formats existed:
- 8-inch;
The first type of floppy disk that became widespread among PC users was the eight-inch drive.
Externally, it has a rectangular shape and is made of polymer materials.
The magnetic mechanism itself is located inside a plastic case. Inside there is a special recess with which the drive reads information from. After the drive starts up, the device reads the location of the first track. This is how the process of “decrypting” information from the floppy disk begins.
An eight-inch floppy disk can have a capacity of 80 KB, 256 KB, or 800 KB. Over time, such a volume of information even became insufficient, so the development of floppy disks with a larger volume began.
- 5.25 inches;
This generation of floppy disks is practically no different in appearance from eight-inch drives.
The only difference- improved index holes for data reading.
Thanks to the use of new technology for creating material for the case, the disc was preserved for a longer time and was resistant to scratches and drops from low heights.
These types of floppy disks were either single-sided or double-sided. To start using the additional side, you just had to turn the drive over. On single-sided models, this action could thin out the drive.
5.25-inch floppy disks could store 110 KB, 360 KB, 720 KB, or 1200 KB of information.
The production of such floppy disks ended in the early 2000s.
- 3.5 inches;
The 3.5-inch floppy disk is the most popular floppy drive option.
Externally, it differs from previous generations with an even more durable body, as well as a completely solid surface.
In this type of floppy disk, it became possible to install .
it can be configured by the floppy disk user before the first recording of information to removable media.
The capacity of a 3.5 floppy disk is determined by the square holes in the lower right corner of the device. One square - capacity 720 KB, two - 1.44 MB and three - 2.88 MB.
Despite all the disadvantages of using floppy disks, namely low capacity and sensitivity to the influence of magnetic fields, the 3.5 floppy disk was popular even after the release of optical disks.
All because of the convenience of data transfer and the cheap cost of floppy disks and disk drives.
Iomega Zip.
This type of drive became intermediate between the eras of floppy disks and optical disks.
Externally, Iomega looks like a floppy disk, but the device's body is flexible.
Due to its high cost and lack of manufacturer interest in such a floppy disk, Iomega never became more popular than standard 3.5-inch floppy disks.
Iomega capacity reached 750 MB.
Also, the device was distinguished by high speed of reading and processing data.
Why is a floppy disk needed today?
Despite the widespread belief that the era of floppy disks is over, you can still encounter floppy disks in many areas.
In the CIS, floppy disks are still used in government agencies to record citizens' data.
Eg, tax departments store data about taxpayers in the form of floppy disks. The use of such an outdated drive is explained by the fact that they still store records from 10 or even 20 years ago. Information does not transfer to newer devices due to lack of funding or lack of new computers.
Also, 3.5-inch floppy disks are used in schools.
Floppy drives are still common in any computer science classroom.
Students bring their homework and hand it in to the teacher. This property is not typical for all, but for most schools. This is explained by outdated equipment.
Floppy disks 3.5 and Pentagon
One of the most interesting uses of floppy disks in the modern world is the Pentagon.
The most high-tech and popular state-level security center still works with ordinary floppy disks.
Of course, Pentagon employees do not store absolutely all information on floppy disks.
According to the organization's 2015 official report, floppy disks work as an additional method of protecting information.
They store data on nuclear weapons and other secret information.
To read and process data, the Pentagon uses old models of computers that do not have and operate without being connected to any networks.
This approach eliminates the possibility of an “over-the-air” hacker attack, which the Pentagon has encountered countless times.
According to the US Department of Defense plan, floppy disks should be phased out at the Pentagon by the end of 2018. It is reported that to increase the level of security of secret data, it is planned to introduce ultra-resistant algorithms and constant monitoring without using the Internet.
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