The evolution of removable media: from floppy disks to magneto-optics. What is a floppy disk? In what generation did floppy disks appear?
Half of the owners of personal computers do not even suspect that there is such a technology as magnetic recording, and the remaining half of users are sure that this recording, including the media - a flexible magnetic disk, has sunk into oblivion. However, if you delve deeper into this issue, you will find that manufacturing plants continue to produce magnetic disks and tapes. For what? Where is obsolete technology used? The focus of this article is magnetic recording on various storage media, technologies of the 20th century.
Historical reference
Many media sources indicate that magnetic disks have replaced magnetic tapes as more compact media. It is not true. In fact, floppy disks are substitutes for punched cards. But they cannot be competitors of magnetic tapes for one simple reason - their capacities are incommensurable.
The very first magnetic disk was released by IBM, which in 1971 showed the world a floppy disk with an eight-inch diameter and a disk drive capable of writing and reading data from a storage medium. The floppy disk capacity was one hundred kilobytes, which was quite enough for storage at that time. A few years later, a five-and-a-quarter-inch media appeared on the market, and in 1981, the world-famous Sony concern introduced a 3.5-inch floppy disk to the market. At first, the floppy disk capacity was 720 kilobytes. But later, thanks to an increase in recording density, media with capacities of 1.44 MB and 2.88 MB appeared.
And if we talk about magnetic recording in general
Information can be transferred not only to a flexible magnetic disk, but also to film and hard media. The principle of recording on soft media is known to everyone. Recording on magnetic media is carried out sequentially. Accordingly, reading should occur in the reverse way. This is a huge disadvantage. But there are also advantages, because, thanks to the high recording density, one medium can store a large amount of information. An example of such devices are streamers. But writing to a hard drive allows you to access data much faster thanks to only two mechanisms - a rotating spindle, which spins the surface of the disk with data, and a moving head that reads information.
At the pinnacle of glory
If the capacity of flexible magnetic disks is limited by the surface area of the media, then the soft film can be wound on a reel half a kilometer long. What is actively being done by manufacturing plants. In the 21st century, interest in streamers not only has not faded, but, on the contrary, has grown. Manufacturers are developing and improving new technologies for these devices. One such small medium with magnetic tape can record from 0.5 to 4 terabytes of information. Tape drives are widely used in large corporations to store database archives. In film studios, films sent to the archive are placed on media. Administrators of large Internet resources store backup copies of all important sites on streamer cartridges. And all this thanks to several devices that have not yet been surpassed by any technology.
- Huge recording density with small media sizes.
- Low power consumption compared to similar high-capacity media.
- High reliability and stability.
A triumph that never came
As you know, a monopoly on the market makes it possible to set your own prices, but you shouldn’t expect any grandiose development from products that have no analogues. It turned out that the little-known company Iomega Zip entered the IT technology market at the end of the 20th century with an innovation that had no analogues in the world. A disk drive and 3.5-inch floppy disk drives for it were introduced, allowing you to record data of 100, 250 and 750 megabytes in size on one medium. The price of such a device was so high that not only ordinary users, but also huge corporations chose to refrain from purchasing it. Due to low demand, the manufacturer was not immediately aware that a damaged floppy disk was damaging the drive. The development of technology was prevented by laser recording, information about which was not classified from other manufacturers.
Device and design of a flexible information storage device
The word “floppy disk” was derived from the English word diskette, which in turn became an abbreviation for floppy disk. Translated, floppy means “flexible”. The result is literally a flexible magnetic disk. What is it called - we figured it out. It remains to understand its design. The principle of operation comes down to the presence of a marked area on the surface of the media and a head capable of recording and reading, which is located in the drive. In addition, the drive contains a special shaft that rotates the flexible disk. Access to the surface of the magnetic medium is carried out through a special floppy disk window, the length of which allows the head to move along the entire radius of the disk surface. To protect the magnetic surface, the window is protected by a special shutter, which opens mechanically when a floppy disk is inserted into the drive. The absence of a curtain does not affect the performance of the device, but may lead to surface contamination, since the structure of the magnetic disk is capable of attracting dust.
Operating principle and small oddities
The principle of recording a magnetic layer on a flexible medium is quite interesting. In addition to the recording head, the device has two monitoring heads, which are located behind the main one and offset to the sides from each other. Their task is to protect the overwriting of information on tracks located next to the one being recorded. If the writing magnetic head has affected nearby information with a strong impulse, the control head cancels this change. It looks quite strange from the outside. After all, if you take a hard magnetic disk for comparison, you can see that it has only one head for each surface of the disk. The fact is that the write head built into the floppy disk drive does not have high-frequency bias due to the complexity of its design. That's why such a simple and inexpensive solution was found.
Displacement of technology from the IT market
Just a few years ago, when purchasing a personal computer, floppy disk drives were a mandatory attribute in the system unit. But interest in the device among users quickly faded. And now the presence of a 3.5-inch disk drive indicates that the PC owner has a weak computer. There are many reasons for the disappearance of flexible drives from the market. Here are a few of them.
- Small recording capacity. In fact, you can't even record one song on a disc.
- Unreliability of information storage. A floppy disk becomes demagnetized when exposed to large magnetic fields. For example, a one-time trip on a trolleybus or metro can format a floppy disk.
- Even the nonsense launched in the media by SSD drive manufacturers about the dangerous effects of a hard magnetic drive and all drives with this technology has yielded results.
Safety first
This may seem strange, but the floppy disk is very popular in US government agencies, including the presidential administration. The magnetic disk is designed to authorize users when logging into the control system. While the whole world has switched to using USB dongles, America is using technology from the last century. This approach is explained by the fact that very often, having taken possession of a USB key, a fraudster gains access to sensitive information. Many feature films reveal this problem in the plot.
With magnetic disks everything is different. The advantages and disadvantages of floppy disks play a big role at the same time. In addition to low cost, small size, the ability to rewrite, quickly read, and detect the media by any operating system without drivers, the advantages include easy removal of the media. Naturally, without the possibility of recovery. This is the main advantage of a floppy disk. In case of an unforeseen situation, the media can be easily destroyed along with important information. Obtaining a new key will not be difficult; to do this, just contact the security service of your structure.
Education system
But Russian children know more about floppy disks than their parents. After all, most Russian schools still have personal computers with a built-in floppy drive. And thanks to school computer science programs, which have not undergone any significant changes over several years, all students also receive practical skills in using magnetic disks. After all, the volume of a floppy disk allows you to store two entry-level programming languages on one medium, along with completed assignments for the entire year of study. And without basic knowledge of the programming languages BASIC and Turbo Pascal, not a single technical university will open its doors to an applicant.
System Administrator Tool
It is a floppy magnetic disk, and not a USB drive, that a system administrator uses to update the firmware of system devices, servers and control systems. In addition, the floppy disk is used to transfer authorization keys, system equipment settings, and configure controllers and arrays. Not to mention the fact that banal damage to the BIOS of any personal computer can be corrected either using a floppy disk or a programmer. There are several reasons for the active use of a floppy magnetic disk.
- To read data from the media, a disk drive built into the device is used, which does not require drivers to operate. No detection or configuration.
- There has been nothing cheaper on the market for a decade than a disk drive and media with the same fault tolerance.
- There is no need for large amounts of information - 1.44 MB for Unix-based systems is enough to save the necessary data.
About programmers' entertainment
Due to the fact that the structure of the magnetic disk is a spiral, the read head has to constantly move along the surface of the media. At the same time, which moves this head, creates a specific sound in the drive, which is very clearly audible in a large room. This is exactly what programmers have been using for many years. Using one of the low-level programming languages (Turbo Pascal or C+), with the help of special commands, you can achieve stepper control using sequential and short-term computer access to different data recorded throughout the disk. Many people manage to reproduce a very complex melody using several disk drives, each of which acts as one instrument. You can learn more about this type of entertainment in the media.
Finally
There is only one conclusion: a flexible magnetic disk, like a hard disk, is too early to be written off. Having worked in the IT field for about 25 years, floppy disks and hard drives remain in demand in many areas of human activity. Along with the disadvantages that are attributed to these storage media, they also have many advantages that can be seen when trying to get to know the technology better. Naturally, you should not pay attention to the nonsense of narrow-minded people who talk about the dangerous effects of a hard magnetic disk, and of magnetic recording in general. All equipment massively presented on the market undergoes more than one certification before hitting the shelf.
A floppy disk is a portable magnetic storage medium used for repeated recording and storage of relatively small data. This type of media was especially common in the 1970s - late 1990s. Instead of the term “floppy disk”, the abbreviation GMD is sometimes used - “floppy magnetic disk” (accordingly, a device for working with floppy disks is called NGMD - “floppy magnetic disk drive”).
Typically, a floppy disk is a flexible plastic plate coated with a ferromagnetic layer, hence the English name “floppy disk”. This plate is placed in a plastic case that protects the magnetic layer from physical damage. The shell can be flexible or rigid. Writing and reading floppy disks is carried out using a special device - a floppy disk drive (floppy drive).
Floppy disks typically have a write-protect feature that allows read-only access to the data.
Story
- 1971 - The first floppy disk with a diameter of 200 mm (8″) and a corresponding floppy drive was introduced by IBM. The invention itself is usually credited to Alan Shugart, who worked for IBM in the late 1960s.
- 1973 - Alan Shugert founded his own firm, Shugart Associates.
- 1976 - Alan Shugert developed the 5.25″ floppy disk.
- 1981 - Sony introduces the 3.5″ (90 mm) floppy disk to the market. In the first version, the volume is 720 kilobytes (9 sectors). The later version has a capacity of 1440 kilobytes or 1.40 megabytes (18 sectors). It is this type of floppy disk that becomes the standard (after IBM uses it in its IBM PC).
- Later, the so-called ED floppy disks (from the English Extended Density - “extended density”) appeared, which had a volume of 2880 kilobytes (36 sectors), which never became widespread.
Formats
| Chronology of the emergence of floppy disk formats | ||
| Format | Year of origin | Volume in kilobytes |
| 8 | 1971 | 80 |
| 8" | 1973 | 256 |
| 8" | 1974 | 800 |
| 8″ double density | 1975 | 1000 |
| 5.25″ | 1976 | 110 |
| 5.25″ double density | 1978 | 360 |
| 5.25″ quad density | 1982 | 720 |
| 5.25″ high density | 1984 | 1200 |
| 3″ | 1982 | 360 |
| 3″ double density | 1984 | 720 |
| 3.5″ dual density | 1984 | 720 |
| 2″ | 1985 | 720? |
| 3.5″ high density | 1987 | 1440 |
| 3.5″ extended density | 1991 | 2880 |
It should be noted that the actual capacity of floppy disks depended on how they were formatted. Since, except for the earliest models, virtually all floppy disks did 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. 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 MX, MY used in DCK).
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 Apple introduced high-density SuperDrive disk drives that operated in both modes.
The "standard" IBM PC floppy disk formats differed in the size of the disk, the number of sectors per track, the number of sides used (SS stands for single-sided floppy, DS stands for double-sided), and the type (recording density) of the floppy drive. The drive type was marked as SD - single density, DD - double density, QD - quadruple density (used in clones such as Robotron-1910 - 5.25″ floppy disk 720 K, Amstrad PC, PC Neuron - 5.25″ floppy disk 640 K , HD - high density (differed from QD in the increased number of sectors), ED - extended density.
8-inch drives have long been included in the BIOS and supported by MS-DOS, but there is no clear information on whether they were shipped to consumers (they may have been shipped to businesses and organizations and not sold to individuals). In addition to the above format variations, there were a number of improvements and deviations from the standard floppy disk format.
The most famous - 320/360 KB floppy disks Iskra-1030/Iskra-1031 - were actually 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 (800.com), and the Iskra-1030/Iskra-1031 disk drive, accordingly, could not read standard DS/DD floppy disks from the IBM PC.
Special driver-extenders BIOS 800, pu_1700 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 4 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 3.5″ HD drives was 1700 KB.
This technique was subsequently used in Windows 98, as well as Microsoft's DMF floppy disk format, which expanded the capacity of floppy disks to 1.68 MB by formatting floppy disks into 21 sectors in a similar IBM XDF format. XDF was used in OS/2 distributions, and DMF was used in distributions of various Microsoft software products.
The pu_1700 driver also made it possible to provide formatting with shifting and interleaving of sectors - this accelerated sequential read-write operations, but did not allow compatibility even with the standard number of sectors, sides and tracks. Finally, a fairly common modification of the format of 3.5″ 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 3.5″ is typical for Japan and South Africa. As a side effect, activating this BIOS setting usually makes it possible to read floppies formatted with 800-type drivers.
Additional (non-standard) tracks and sectors sometimes contained copy protection data for proprietary floppy disks. Standard programs such as diskcopy did not transfer these sectors when copying. The unformatted capacity of a 3.5″ floppy disk, determined by the recording density and storage area, is 2 MB.
The height of a 5.25″ floppy drive is 1 U. All CD drives, including Blu-ray drives, are the same width and height as a 5.25″ floppy drive (this does not apply to laptop drives). The width of the 5.25″ drive is almost equal to three times its height. This was sometimes used by computer case manufacturers, where three devices placed in a square “basket” could be reoriented with it from a horizontal to a vertical orientation.
A little over forty years ago the first computer floppy disks appeared, and thirty years ago the well-known 3.5-inch floppy disks were released. And they are still being produced! Nowadays, flash drives and external hard drives are used to transfer information, and all previous developments have almost been consigned to oblivion. IT. TUT.BY studied which removable media left a noticeable mark on computer history, and which could become a standard for many years to come.
Here we will consider only floppy disks and cartridges with magneto-optical disks that were inserted into reading devices, and we will not disassemble ordinary disks and tape drives.
8" floppy disk
Developer: IBM
Year of manufacture: 1971
Dimensions: 200x200x1 mm
Volume: from 80 KB at the beginning of release to 1.2 MB
Distribution: ubiquitous
In 1967, a group was organized at IBM under the leadership of Alan Shugart to develop new floppy disks. In 1971, the first eight-inch floppy disk was released onto the market: a round, flat, flexible disk in a plastic envelope measuring 20x20 cm. Because of its flexibility, the new product was named Floppy Disc. At first, the capacity was only 80 kilobytes, but over time the recording density was increased, and after five years floppy disks could already hold more than a megabyte of information.
5.25" floppy disk (Mini Floppy Disk)
Developer: Shugart Associates
Year of manufacture: 1976
Dimensions: 133x133x1 mm
Volume: from 110 KB at the beginning of release to 1.2 MB
Data transfer speed: up to 63 Kb/s
Distribution: ubiquitous
Two years after the release of the first eight-inch floppy disks, Alan Shugart founded his own company, Shugart Associates, which three years later introduced a new development - a five-inch floppy disk and floppy drive. The company was also noted for the development of the SASI standard, which was later renamed SCSI. Floppy disks were either single-sided or double-sided, and many computer designers used their own formatting methods and writing algorithms, which meant that disks written in one drive might not be readable in another. Schoolchildren during the decline of the USSR and the first years of independence of the Union republics loaded computers from such floppy disks and played simple games. By the mid-eighties, the capacity of floppy disks had been increased tenfold. And Shugart Associates, by the way, subsequently changed its name to the well-known Seagate.
3.5" floppy disk (Micro Floppy Disk)
Developer: Sony
Year of manufacture: 1981
Dimensions: 93x89x3 mm
Volume: from 720 KB at the beginning of release to 1.44 MB (standard), to 2.88 MB (Extended Density)
Data transfer speed: up to 63 Kb/s
Distribution: ubiquitous
In 1981, Sony offered a completely new type of floppy disk: three-inch. They were no longer truly flexible, but the name remained. Now the magnetic circle was enclosed in plastic three millimeters thick, and the hole for the heads was covered with a curtain on a spring. These curtains, especially the metal ones, became loose and bent during use, and often came off inside the drive and remained there. Floppy disks became very popular, and various computer manufacturers equipped their machines with them. Sony produced several models of digital cameras that recorded on floppy disks. The standard capacity of floppy disks had already grown to 1.44 MB by 1987, and a little later, thanks to an even higher recording density, it was possible to “squeeze out” up to 2.88 MB. Cunning students in dormitories (including Belarusian ones) used money to “overclock” floppy drives to 1.7-1.8 MB, and they could be read in ordinary disk drives. Despite everything, three-inch floppy disks are still produced. Floppy disks have almost gone out of use, but many programs still have the “Save” command icon in the form of a floppy disk.
Amstrad Disc 3" (Compact Floppy Disc, CF2)
Developer: Hitachi, Maxell, Matsushita
Year of manufacture: 1982
Dimensions: 100x80x5 mm
Volume: from 125 KB at the beginning of release to 720 KB
Distribution: quite wide - mainly Amstrad CPC and Amstrad PCW computers, also Tatung Einstein, ZX Spectrum +3, Sega SF-7000, Gavilan SC
Amstrad, a well-known computer manufacturer, decided to go its own way and promoted three-inch floppy disks of a different format from Hitachi. Even more surprising is that the company was founded by the same Alan Shugart who developed the first floppy disks. The magnetic disk itself inside the case took up less than half of the free space - the rest was accounted for by media protection mechanisms, which is why the cost of these disks was quite high. Despite the fact that these floppy disks were more expensive than standard 3.5-inch floppy disks with less memory, the company promoted them for quite a long time and succeeded a lot: more than 3 million Amstrad CPC computers alone were produced.
Bernoulli Box
Developer: Iomega
Year of manufacture: 1983
Dimensions: Bernoulli Box: 27.5x21 cm, Bernoulli Box II: 14x13.6x0.9 cm
Volume: from 5 MB at the beginning of release to 230 MB
Data transfer speed: up to 1.95 Mb/s
Distribution: small
Iomega, later one of the main “whales” of the removable media market, developed the original Bernoulli Box drive in 1983. In it, the floppy disk rotates at high speed (3000 revolutions per minute), as a result of which the surface of the disk directly under the read head bends and does not contact it: read / write operations are performed through an air cushion. Equations for describing these air flows were proposed by the prominent Swiss scientist Daniel Bernoulli back in the 18th century. Thanks to this development, the company gained fame, although the first products were not distinguished by either capacity or portability: the first cartridges were 27.5x21 cm in size and held only 5 megabytes of information. The second generation decreased in size by approximately four times, and by 1994 the memory capacity increased to 230 megabytes. But by that time, magneto-optical disks began to actively promote.
Magneto-optical drive (MO)
Developer: Sony
Year of manufacture: 1985
Dimensions: 133хх133х6 mm, 93х89х6 mm, 72х68х5 mm for MiniDisc
Volume: from 650 MB to 9.2 GB for 5-inch, from 128 MB to 2.3 GB for 3.5-inch, 980 MB for minidisks
Data transfer speed: up to 10 Mb/s
Distribution: significant
Magneto-optical discs look like regular standard-size and smaller-size CDs housed in a case. But at the same time, they have an important difference: recording is carried out using the magnetic method, that is, first the laser heats the surface to a high temperature, and then an electromagnetic pulse changes the magnetization of the areas. The system is highly reliable and resistant to mechanical damage and magnetic radiation, but it provided a low recording speed and had high energy consumption. Both disks and drives were expensive, so magneto-optics did not become very widespread like CDs. The spread was also hampered by the fact that for a very long time such disks allowed data to be written only once. But in some industries (for example, medicine), where the preservation of a large amount of information for a long time is required (and MO disks “live” up to 50 years), the technology has gained recognition. Sony still produces magneto-optical drives in both small and large sizes. MiniDisc music discs, introduced by the same Sony company in 1992, are a special case of magneto-optical discs. If at first they only allowed recording music, then modifications MD Data (1993) and Hi-MD (2004) provide recording of any data with a capacity of 650 MB and 980 MB, respectively. Minidiscs are also still being produced.
SyQuest drives
Developer: SyQuest
Year of manufacture: around 1990
Dimensions: 5.25" (approx. 13x13 cm) and 3.5" (approx. 9x9 cm) format
Volume: 5.25": 44, 88 and 200 MB; 3.5": 105 and 270 MB
Distribution: medium (mostly with MacIntosh computers)
QyQuest, founded in 1982 by former Seagate employee Syed Iftikhar, entered the market with removable hard drives for IBM XT computers. The company later developed several different disk-cartridge systems. The most popular are the 5.25-inch SQ400/SQ800/SQ2000 cartridges (44, 88 and 200 MB in capacity), as well as the 3.5-inch SQ310/SQ327 (105 and 270 MB in capacity). Their main disadvantage, besides their size, was that later systems were not fully compatible with earlier ones. Thus, drives for 200-megabyte disks could only read 88-megabyte disks, but could not write to them. The younger systems could neither read nor write to the older ones. In the year of release, 44-megabyte disks cost about $100. The variety of incompatible standards and the lack of a normal trade name for this or that technology did not allow the disks to gain wide popularity. Magneto-optical drives provided more capacity, and Iomega's Zip drives soon followed.
Floptical
Developer: Insite Peripherals
Year of manufacture: 1991 (Insite Floptical), 1998 (Caleb UHD144, Sony HiFD)
Dimensions: 93x89x3 mm
Volume: 21 MB (Insite Floptical), 144 MB (Caleb UHD144), 150-200 MB (Sony HiFD)
Data transfer speed: up to 125 Kb/s
Distribution: very low
Another magneto-optical technology, but of a different type. Information is read by magnetic heads, and the optical subsystem (infrared LEDs) ensures accurate head positioning. Thus, instead of the usual 135 tracks per inch, like floppy disks, a recording density of 1250 tracks per inch was achieved here. Floptical drives were compatible with regular 3.5-inch floppy disks, and at first Floptical disks were positioned as a successor to floppy disks, but this did not happen. Seven years later, Caleb Technology developed its own similar system, the Caleb UHD144, and Sony released Sony HiFD discs. Both of these systems were also compatible with regular floppy disks and both were also called floppy disk replacements, but they were a resounding failure in the market, because by that time the market for 100-250 MB removable media had been captured by Iomega's Zip disks.
Zip Drive (Iomega Zip)
Developer: Iomega
Year of manufacture: 1994
Dimensions: 98x98x6 mm
Volume: from 100 MB at the beginning of release to 750 MB
Data transfer speed: about 1 Mb/s
Distribution: very wide
CDs were still expensive and did not allow erasing records (CD-RWs appeared only in 1997), magneto-optical disks were expensive and power-hungry, and the capacity of ordinary floppy disks was no longer enough. Iomega has improved its magnetic recording technology and introduced Zip disks: slightly larger in size than floppy disks, and with a capacity of as much as 100 megabytes. The head was connected to the disk not from above, but from the side, and the data exchange speed was approximately 15 times faster than that of conventional floppy disks. The drives came in several formats - both external and internal, sleek in shape and blue in color, which could be placed flat or vertical on a table. The technology quickly gained popularity. Despite the “clicks of death”, which were a sign of disk failure, the “zip” sold successfully. In the year of release, disk drives cost $100 and disks cost $20; later, 250-megabyte disks (round in shape, but the same dimensions) and 750-megabyte disks (of the usual shape) appeared. Since the early 2000s, the popularity of Zip drives has declined, but Iomega still sells 100-megabyte drives for $9 apiece, and “seven hundred and fifty” drives for $12.50. Many vintage technology enthusiasts still use epoch-making devices.
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And the controller of such a device is usually denoted by the abbreviation KMD.
Floppy disks typically have a write-protect feature that allows read-only access to the data. Floppy disks were widely used from the 1970s until the end of the 1990s, giving way to more capacious and convenient DVDs and flash drives.
An intermediate option between them and traditional floppy disks are more modern floppy disk drives using cartridges - Iomega Zip, Iomega Jaz; as well as magneto-optical media (MO), LS-120 and others, which combined a laser (used to heat a section of the disk surface) and a magnetic head (for writing and reading information from the disk surface).
Story
- - Alan Shugart led the team that developed disk drives in the IBM laboratory where floppy disk drives were created. David Noble (ur. David Noble), one of the senior engineers working under his leadership proposed a floppy disk (prototype of an 8″ floppy disk) and a protective cover with a fabric lining.
- - IBM presented the first floppy disk with a diameter of 8″ (200 mm) with a corresponding disk drive.
- - Alan Shugart founds his own firm, Shugart Associates.
- - Finn Conner Finis Conner) invited Alan Shugart to take part in the development and production of disk drives with 5¼″ diameter disks, as a result of which Shugart Associates, having developed the controller and the original Shugart Associates SA-400 interface, released a disk drive for mini-floppy 5¼″ floppy disks, which, quickly replacing 8″ disk drives, became popular in personal computers. Shugart Associates also created the Shugart Associates System Interface (SASI), which was renamed the Small Computer System Interface (SCSI) after formal approval by the ANSI committee in 1986.
- - Sony introduces a 3½″ (90 mm) floppy disk to the market. In the first version (DD) the volume is 720 kilobytes (9 sectors). In 1984, Hewlett-Packard first used this drive in its HP-150 computer. The later version (HD) has a volume of 1440 kilobytes or 1.44 megabytes (18 sectors).
- 1984 - Apple began using 3½″ drives in Macintosh computers
- 1987 - 3½″ HD drive appeared in IBM PS/2 computer systems and became the standard for mass-market PCs.
- 1987 - Ultra-high-density disk drives developed in the 1980s by Toshiba Corporation are officially introduced. Extra High Density, ED) the carrier for which was a floppy disk with a capacity of 2880 kilobytes or 2.88 megabytes (36 sectors).
- 2011 - Sony in March 2011 put an end to the history of floppy disks by officially ceasing the production and sale of 3½″ floppy disks.
Formats, depending on disc diameter
8"
Structurally, an 8″ floppy disk is a disk made of polymer materials with a magnetic coating, enclosed in a flexible plastic case. The case had holes: a large round one in the center for the spindle, a small round one for the index hole window that allows you to determine the beginning of the sector, and a rectangular one with rounded ends for the magnetic heads of the drive. There was also a recess at the bottom; by removing the sticker from it, you could protect the disc from writing.
Floppy disk formats differed in the number of sectors per track. Depending on the format, 8″ floppy disks contained the following amounts of information: 80, 256 and 800 KB.
5¼″
5¼″ floppy disk
The design of a five-inch floppy disk differed little from an eight-inch one: the index hole window was located on the right and not on the top, and the write protection slot was also on the right side of the floppy disk. To better preserve the disc, its case was made more rigid and reinforced around the perimeter. To prevent premature wear, an anti-friction pad was placed between the case and the disk, and the edges of the drive hole were reinforced with a plastic or metal ring (this ring was usually absent in high-density floppy disks, since errors in its location on the diskette can lead to problems arising when positioning the heads).
There were floppy disks with a rigid breakdown into sectors: they were distinguished by the presence of several index holes according to the number of sectors. This scheme was later abandoned.
Both floppy disks and five-inch disk drives came in single- and double-sided versions. When using a single-sided drive, it was not possible to read the second side simply by turning the floppy disk over due to the location of the index hole window - this would require the presence of a similar window located symmetrically to the existing one. The data protection mechanism was also revised - the window was located on the right, and a sealed hole meant a protected disk. This was done to protect against incorrect installation.
Recording formats on five-inch floppy disks made it possible to store 110, 360, 720 or 1200 kilobytes of data on it.
3½″
The fundamental difference between a 3½″ floppy disk is its hard plastic casing. Instead of an index hole, 3½" floppy disks use a metal sleeve with an index hole that is located in the center of the diskette. The drive mechanism grips a metal sleeve, and the hole in it allows the floppy disk to be positioned correctly, so there is no need to make a hole directly in the magnetic disk for this. Unlike 8″ and 5¼″ floppy disks, the window for the heads of a 3½″ floppy disk is closed by a sliding metal flap, which opens when it is inserted into the drive. Write protection is provided by a sliding curtain in the lower left corner. At the bottom right there are windows that allow the drive circuit to determine the recording density of the floppy disk based on the number of holes:
- no - 720 KB,
- one - 1.44 MB,
- two - 2.88 MB.
Despite many disadvantages - sensitivity to magnetic fields and insufficient capacity by the mid-90s, the 3½″ format lasted on the market for more than a quarter of a century, leaving only after the advent of affordable flash memory-based drives.
3½″ floppy disk device
1 - window that determines the recording density (on the other side there is a write protection switch); 2 - disk base with holes for the drive mechanism; 3 - protective curtain of the open area of the body; 4 - plastic floppy body; 5 - anti-friction gasket; 6 - magnetic disk; 7 - recording area (one sector of one track is conventionally highlighted in red).
Iomega Zip
Floppy disk Zip-250
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. 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's existence - 750 MB. In addition to their larger capacity, Zip drives provided more reliable data storage and higher 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 disk inserted into it. after that a floppy disk.
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 depended on how they were formatted. Since, except for the earliest models, virtually all floppy disks did 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 (English) Single Density, single density, first appeared on the IBM System 3740),
- DD (English) Double Density, double density, first appeared in IBM System 34),
- QD (English) Quadruple Density, quadruple density, used in domestic clones Robotron-1910 - 5¼″ floppy disk 720 K, Amstrad PC, PC Neuron - 5¼″ floppy disk 640 K),
- HD High Density, high density, differed from QD in the increased number of sectors),
- ED (English) 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 | 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) | 2 | 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 |
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 800-type drivers.
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 - they were actually 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.
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, when moving to the next cylinder, ended up in front of the first sector. 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 be 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 4 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 Microsoft's DMF floppy disk formats, which expanded the capacity of floppy disks to 1.68 MB by formatting floppy disks into 21 sectors (for example, in Windows 95 distributions), similar to IBM's XDF format, which was used in OS/2 distributions.
Security of information
One of the main problems associated with the use of floppy disks was their fragility. A magnetic disk could relatively easily become demagnetized from exposure to magnetized metal surfaces, natural magnets, or electromagnetic fields near high-frequency devices, which made storing information on floppy disks quite unreliable.
The most vulnerable element of the floppy disk design was the tin or plastic casing that covered the floppy disk itself: its edges could bend, which led to the floppy disk getting stuck in the drive; the spring that returned the casing to its original position could move, as a result the floppy casing was separated from the case and no longer returned to initial position. The plastic case of the floppy disk itself did not provide sufficient protection for the floppy disk from mechanical damage (for example, when the floppy disk was dropped on the floor), which rendered the magnetic medium inoperable. Dust could get into the cracks between the floppy disk body and the casing.
The massive displacement of floppy disks from everyday use began with the advent of rewritable CDs, and especially flash memory-based media, which have orders of magnitude greater capacity, higher exchange speeds, and a greater actual number of rewrite cycles and durability.
Current situation
External drive with USB interface
Currently, the use of floppy disks has practically ceased. Since 2010, a large number of motherboards for desktop personal computers have been produced that do not contain a connector for connecting a disk drive at all. Built-in disk drives completely disappeared from laptops a few years earlier.
Electronic keys when working with Bank-Client systems, providing an electronic digital signature of a document, previously distributed on floppy disks, are increasingly being produced in the form of a flash drive with a biometric protection function.
When installing drivers for equipment (for example, a RAID array) during the installation of modern operating systems of the MS Windows family (Windows Vista, Windows Server 2008 R2, Windows 7), a flash drive can also be used.
If there are no drives connected to the corresponding “classic” interface connector on the motherboard, you can use an external device that has a USB or SCSI interface.
Floppinet
The English name of the floppy disk “floppy disk” owes its appearance to the informal term “Floppinet”, which denotes the use of removable storage media (primarily floppy disks) for transferring files between computers. The prefix “-no” ironically compares this method of transmitting information with the semblance of a computer network at a time when the use of a “real” computer network is impossible for some reason. The term "floppy disk networks" is also sometimes used.
Symbolism
The image of a three-inch floppy disk is still used in GUI applications as an icon for buttons and menu items. Save.
Notes
Literature
- Voroisky F. S. Computer science. New systematic explanatory dictionary-reference book. - 3rd ed. - M.: FIZMATLIT, 2003. - 760 p. - (Introduction to modern information and telecommunication technologies in terms and facts). - ISBN 5-9221-0426-8
Links
A floppy disk or floppy magnetic disk (FMD) is a magnetic device for storing data, with the ability to repeatedly read and write information. It is a square structure, inside of which there is a plastic disk with a magnetic surface. The box itself, inside of which this disk is located, is made of either hard or soft plastic. Reading and writing data is performed using a special drive, which uses a magnetic head for these actions (in some ways a prototype of today's hard drives).
Previously, in various system errors you could find references to “floppy-disk”. If you have seen this, then we are talking about floppy disks. The first floppy disks were as large as 8 inches, but gradually reached 3.5 inches (there are also 2-inch options). The first variations made it possible to save as much as 80 KB of data. The last common option allowed you to save 1.44 MB. At one time, each of these volumes represented quite a lot of space.
Some of the notable features of this medium include:
1. Floppy disks had to be periodically formatted in order to preserve the properties of the magnetic surface of the disk. They were repaired using the same method.
2. Some floppy disks have write protection - a small hole in the box. If this hole is not closed, then recording cannot be performed. This point was often confused, as there was some illogicality.
3. Despite the fact that the disk is called flexible, it cannot be bent. However, you can’t touch the disk itself or anything else with your hands.
4. The floppy disk should not be removed while reading or writing, as in this case the data could easily be damaged. When reading and writing, it was clearly audible how the drive moved the head.
5. Since information is stored on a magnetic disk, the floppy disk should not be stored near magnets or devices that create a magnetic field. In a sense, it is easy to quickly erase information from floppy disks, all you need is a strong magnet.
6. Many floppy disks usually came with paper stickers or they were already pasted on, so you could write what was stored on a given floppy disk.
7. Floppy disks were actively used for 40 years - quite a significant period.
8. At one time, it was floppy disks that served as a hard drive, since computers did not have their own data storage device for permanent storage.
9. Previously, a lot of programs and toys could fit on floppy disks (for example, in the era of 286 - 486 computers).
Today, it is quite difficult to find a floppy disk, since it has practically gone out of industrial production. The problem was the volume of data. The fact is that the maximum size of data that can be saved on such a medium is 2.88 MB, which is very small given today's data volumes.