banner



Home  ›  Floppy Disk 5 1 4 Usb

Floppy Disk 5 1 4 Usb

Written By Friday, September 23, 2022 Add Comment Edit

Removable disk storage medium

8-inch, 5¼-inch, and three½-inch floppy disks

viii-inch, 5¼-inch (total pinnacle), and iii½-inch drives

A 3½-inch floppy deejay removed from its housing

A floppy deejay or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolete blazon of deejay storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks shop digital information which can be read and written when the disk is inserted into a floppy disk drive (FDD) connected to or within a computer or other device.

The first floppy disks, invented and made by IBM, had a deejay diameter of 8 inches (203.2 mm).[1] Later on, the five¼-inch and then the 3½-inch became a ubiquitous class of data storage and transfer into the first years of the 21st century.[2] three½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for v¼-inch, 8-inch, and other-size floppy disks are rare to non-existent. Some individuals and organizations continue to use older equipment to read or transfer data from floppy disks.

Floppy disks were so common in late 20th-century culture that many electronic and software programs continue to use relieve icons that look like floppy disks well into the 21st century. While floppy disk drives still take some express uses, especially with legacy industrial figurer equipment, they accept been superseded by data storage methods with much greater information storage capacity and data transfer speed, such equally USB flash drives, retentivity cards, optical discs, and storage available through local computer networks and cloud storage.

History [edit]

viii-inch floppy disk,
inserted in drive,
(iii½-inch floppy diskette,
in front, shown for scale)

iii½-inch, high-density floppy diskettes with agglutinative labels affixed

The get-go commercial floppy disks, adult in the late 1960s, were 8 inches (203.2 mm) in diameter;[1] [2] they became commercially available in 1971 every bit a component of IBM products and and then were sold separately starting in 1972 by Memorex and others.[3] These disks and associated drives were produced and improved upon past IBM and other companies such as Memorex, Shugart Associates, and Burroughs Corporation.[four] The term "floppy disk" appeared in impress as early every bit 1970,[v] and although IBM announced its first media as the Blazon 1 Diskette in 1973, the industry connected to use the terms "floppy disk" or "floppy".

In 1976, Shugart Associates introduced the 5¼-inch FDD. By 1978, there were more than than ten manufacturers producing such FDDs.[vi] At that place were competing floppy disk formats, with difficult- and soft-sector versions and encoding schemes such as differential Manchester encoding (DM), modified frequency modulation (MFM), M2FM and grouping coded recording (GCR). The 5¼-inch format displaced the 8-inch one for most uses, and the hard-sectored disk format disappeared. The about common chapters of the 5¼-inch format in DOS-based PCs was 360 KB, for the Double-Sided Double-Density (DSDD) format using MFM encoding. In 1984, IBM introduced with its PC-AT model the 1.ii MB dual-sided 5¼-inch floppy disk, but information technology never became very popular. IBM started using the 720 KB double density 3½-inch microfloppy disk on its Convertible laptop computer in 1986 and the 1.44 MB high-density version with the IBM Personal System/2 (PS/2) line in 1987. These deejay drives could exist added to older PC models. In 1988, Y-E Data introduced a bulldoze for ii.88 MB Double-Sided Extended-Density (DSED) diskettes which was used by IBM in its pinnacle-of-the-line PS/ii models and in the second-generation NeXTcube and NeXTstation; even so, this format had limited market sucesses due to lack of standards and the movement to 3½-inch drives[vii]

Throughout the early on 1980s, limits of the v¼-inch format became clear. Originally designed to be more applied than the 8-inch format, it was becoming considered besides big; every bit the quality of recording media grew, data could be stored in a smaller area.[8] Several solutions were developed, with drives at 2-, ii½-, three-, iii¼-,[9] iii½- and iv-inches (and Sony's xc mm × 94 mm (3.54 in × iii.lxx in) disk) offered by various companies.[viii] They all had several advantages over the old format, including a rigid case with a sliding metallic (or afterwards, sometimes plastic) shutter over the head slot, which helped protect the delicate magnetic medium from dust and damage, and a sliding write protection tab, which was far more convenient than the adhesive tabs used with earlier disks. The large market share of the well-established 5¼-inch format made it difficult for these diverse mutually-incompatible new formats to gain pregnant market share.[viii] A variant on the Sony design, introduced in 1982 past many manufacturers, was then rapidly adopted. By 1988, the three½-inch was outselling the v¼-inch.[x]

Generally, the term floppy disk persisted, even though later manner floppy disks have a rigid case around an internal floppy disk.

By the end of the 1980s, 5¼-inch disks had been superseded by 3½-inch disks. During this time, PCs frequently came equipped with drives of both sizes. By the mid-1990s, five¼-inch drives had nigh disappeared, as the three½-inch deejay became the predominant floppy disk. The advantages of the 3½-inch disk were its higher capacity, its smaller concrete size, and its rigid example which provided ameliorate protection from clay and other environmental risks.

Prevalence [edit]

Imation USB floppy drive, model 01946: an external bulldoze that accepts loftier-density disks

Floppy disks became commonplace during the 1980s and 1990s in their use with personal computers to distribute software, transfer information, and create backups. Earlier hard disks became affordable to the general population,[nb 1] floppy disks were often used to store a calculator's operating system (Bone). Near domicile computers from that time take an elementary OS and BASIC stored in read-only memory (ROM), with the option of loading a more advanced OS from a floppy disk.

By the early 1990s, the increasing software size meant large packages similar Windows or Adobe Photoshop required a dozen disks or more than. In 1996, there were an estimated five billion standard floppy disks in apply.[eleven] And so, distribution of larger packages was gradually replaced by CD-ROMs, DVDs, and online distribution.

An endeavour to enhance the existing 3½-inch designs was the SuperDisk in the late 1990s, using very narrow data tracks and a high precision caput guidance mechanism with a capacity of 120 MB[12] and backward-compatibility with standard 3½-inch floppies; a format war briefly occurred between SuperDisk and other loftier-density floppy-disk products, although ultimately recordable CDs/DVDs, solid-state flash storage, and eventually cloud-based online storage would render all these removable disk formats obsolete. External USB-based floppy disk drives are notwithstanding bachelor, and many modern systems provide firmware support for booting from such drives.

Gradual transition to other formats [edit]

Front and rear of a retail three½-inch and 5¼-inch floppy disk cleaning kit, equally sold in Commonwealth of australia at retailer Big W, circa early 1990s

In the mid-1990s, mechanically incompatible college-density floppy disks were introduced, like the Iomega Zilch disk. Adoption was limited by the competition between proprietary formats and the need to buy expensive drives for computers where the disks would be used. In some cases, failure in market penetration was exacerbated by the release of higher-capacity versions of the drive and media beingness not backward-compatible with the original drives, dividing the users between new and erstwhile adopters. Consumers were wary of making costly investments into unproven and rapidly changing technologies, and then none of the technologies became the established standard.

Apple introduced the iMac G3 in 1998 with a CD-ROM bulldoze just no floppy drive; this made USB-connected floppy drives pop accessories, as the iMac came without whatever writable removable media device.

Recordable CDs were touted every bit an alternative, because of the greater capacity, compatibility with existing CD-ROM drives, and—with the advent of re-writeable CDs and package writing—a similar reusability as floppy disks. However, CD-R/RWs remained mostly an archival medium, not a medium for exchanging data or editing files on the medium itself, because there was no mutual standard for packet writing which allowed for small updates. Other formats, such as magneto-optical discs, had the flexibility of floppy disks combined with greater chapters, but remained niche due to costs. High-capacity backward compatible floppy technologies became popular for a while and were sold as an option or even included in standard PCs, but in the long run, their use was express to professionals and enthusiasts.

Wink-based USB-thumb drives finally were a practical and pop replacement, that supported traditional file systems and all common usage scenarios of floppy disks. As opposed to other solutions, no new drive type or special software was required that impeded adoption, since all that was necessary was an already common USB port.

Usage in the 21st century [edit]

Past 2002, most manufacturers still provided floppy disk drives every bit standard equipment to come across user demand for file-transfer and an emergency boot device, as well every bit for the general secure feeling of having the familiar device.[13] By this time, the retail cost of a floppy drive had fallen to around $twenty (equivalent to $30 in 2021), so there was piffling financial incentive to omit the device from a system. Subsequently, enabled past the widespread support for USB wink drives and BIOS kick, manufacturers and retailers progressively reduced the availability of floppy disk drives as standard equipment. In February 2003, Dell, one of the leading personal computer vendors, announced that floppy drives would no longer be pre-installed on Dell Dimension dwelling computers, although they were still available every bit a selectable option and purchasable as an aftermarket OEM add-on.[xiv] Past January 2007, only 2% of computers sold in stores contained built-in floppy disk drives.[15]

Floppy disks are used for emergency boots in aging systems lacking support for other bootable media and for BIOS updates, since most BIOS and firmware programs can still exist executed from bootable floppy disks. If BIOS updates neglect or become decadent, floppy drives tin can sometimes exist used to perform a recovery. The music and theatre industries all the same use equipment requiring standard floppy disks (due east.chiliad. synthesizers, samplers, pulsate machines, sequencers, and lighting consoles). Industrial automation equipment such as programmable machinery and industrial robots may not have a USB interface; data and programs are then loaded from disks, damageable in industrial environments. This equipment may non be replaced due to cost or requirement for continuous availability; existing software emulation and virtualization do not solve this problem considering a customized operating organization is used that has no drivers for USB devices. Hardware floppy disk emulators can be made to interface floppy-disk controllers to a USB port that tin be used for flash drives.

In May 2016, the U.s. Government Accountability Role released a study that covered the need to upgrade or replace legacy computer systems within federal agencies. According to this document, erstwhile IBM Series/ane minicomputers running on 8-inch floppy disks are yet used to coordinate "the operational functions of the Usa' nuclear forces". The government planned to update some of the applied science by the stop of the 2017 fiscal year.[16] [17]

Windows 10 and Windows eleven no longer comes with drivers for floppy deejay drives (both internal and external). However, they will still back up them with a dissever device driver provided by Microsoft.[18]

The British Airways Boeing 747-400 fleet, up to its retirement in 2020, used 3.5-inch floppy disks to load avionics software.[19]

Some workstations in corporate computing environments still retained floppy disks while disabling USB ports, both moves done society to restrict the amount of information that could be copied past unscrupulous employees.[ dubious – discuss ]

Sony, who had been in the floppy deejay business since 1983, ended domestic sales of all six 3.5-inch floppy disk models every bit of March 2011.[twenty] This has been viewed by some every bit the stop of the floppy disk.[21] Production of new media has ceased[22] but sales and uses of media from inventories all the same continues to this day.[23]

Legacy [edit]

Screenshot depicting a floppy disk equally "save" icon

For more than 2 decades, the floppy disk was the main external writable storage device used. Most computing environments before the 1990s were non-networked, and floppy disks were the primary ways to transfer information between computers, a method known informally as sneakernet. Dissimilar hard disks, floppy disks are handled and seen; fifty-fifty a novice user can place a floppy disk. Because of these factors, a picture of a 3½-inch floppy deejay became an interface metaphor for saving data. The floppy disk symbol is nonetheless used by software on user-interface elements related to saving files (such as Microsoft Part 2021) fifty-fifty though physical floppy disks are largely obsolete, making it a skeuomorph.[24]

Blueprint [edit]

Structure [edit]

8-inch and 5¼-inch disks [edit]

Inside the viii-inch floppy disk

The eight-inch and 5¼-inch floppy disks contain a magnetically coated circular plastic medium with a big circular pigsty in the center for a drive'southward spindle. The medium is independent in a square plastic embrace that has a small oblong opening in both sides to allow the drive's heads to read and write data and a large pigsty in the center to allow the magnetic medium to spin by rotating it from its middle hole.

Inside the cover are two layers of fabric with the magnetic medium sandwiched in the middle. The fabric is designed to reduce friction between the medium and the outer cover, and catch particles of debris abraded off the disk to keep them from accumulating on the heads. The cover is usually a one-role sheet, double-folded with flaps glued or spot-welded together.

A small notch on the side of the deejay identifies that it is writable, detected by a mechanical switch or phototransistor above it; if it is not present, the disk tin be written; in the 8-inch deejay the notch is covered to enable writing while in the 5¼-inch disk the notch is open to enable writing. Tape may be used over the notch to modify the mode of the disk. Punch devices were sold to convert read-only disks to writable ones and enable writing on the unused side of single sided disks; such modified disks became known every bit flippy disks.

Another LED/photo-transistor pair located near the middle of the disk detects the index pigsty in one case per rotation in the magnetic disk; information technology is used to detect the angular start of each runway and whether or not the disk is rotating at the correct speed. Early on 8‑inch and five¼‑inch disks had physical holes for each sector and were termed hard sectored disks. Subsequently soft-sectored disks have only one index hole, and sector position is determined past the disk controller or low-level software from patterns marker the start of a sector. Generally, the same drives are used to read and write both types of disks, with only the disks and controllers differing. Some operating systems using soft sectors, such equally Apple DOS, do not use the index pigsty, and the drives designed for such systems frequently lack the respective sensor; this was mainly a hardware cost-saving measure.[25]

3½-inch deejay [edit]

Rear side of a 3½-inch floppy disk in a transparent case, showing its internal parts

The core of the iii½-inch disk is the aforementioned equally the other two disks, but the front has only a label and a small opening for reading and writing information, protected by the shutter—a jump-loaded metal or plastic encompass, pushed to the side on entry into the drive. Rather than having a pigsty in the center, it has a metal hub which mates to the spindle of the drive. Typical 3½-inch disk magnetic coating materials are:[26]

  • DD: 2 μm magnetic atomic number 26 oxide
  • HD: ane.ii μm cobalt-doped atomic number 26 oxide
  • ED: 3 μm barium ferrite

Two holes at the bottom left and right indicate whether the deejay is write-protected and whether it is high-density; these holes are spaced every bit far apart as the holes in punched A4 paper, allowing write-protected high-density floppies to exist clipped into standard band binders. The dimensions of the disk shell are not quite square: its width is slightly less than its depth, so that it is impossible to insert the disk into a bulldoze slot sideways (i.e. rotated xc degrees from the correct shutter-outset orientation). A diagonal notch at top right ensures that the deejay is inserted into the bulldoze in the correct orientation—non upside down or label-finish beginning—and an arrow at superlative left indicates direction of insertion. The drive usually has a button that, when pressed, ejects the disk with varying degrees of strength, the discrepancy due to the ejection strength provided by the spring of the shutter. In IBM PC compatibles, Commodores, Apple Two/IIIs, and other non-Apple-Macintosh machines with standard floppy deejay drives, a disk may be ejected manually at whatever time. The drive has a disk-modify switch that detects when a deejay is ejected or inserted. Failure of this mechanical switch is a common source of disk corruption if a disk is inverse and the bulldoze (and hence the operating system) fails to find.

I of the chief usability problems of the floppy deejay is its vulnerability; even within a closed plastic housing, the deejay medium is highly sensitive to dust, condensation and temperature extremes. As with all magnetic storage, it is vulnerable to magnetic fields. Blank disks have been distributed with an all-encompassing ready of warnings, cautioning the user not to betrayal it to dangerous conditions. Rough treatment or removing the disk from the drive while the magnetic media is all the same spinning is likely to cause impairment to the deejay, drive caput, or stored data. On the other hand, the 3½‑inch floppy has been lauded for its mechanical usability by human–computer interaction practiced Donald Norman:[27]

A simple example of a proficient blueprint is the 3½-inch magnetic diskette for computers, a pocket-sized circle of floppy magnetic material encased in difficult plastic. Earlier types of floppy disks did not have this plastic case, which protects the magnetic material from corruption and damage. A sliding metal cover protects the frail magnetic surface when the diskette is not in use and automatically opens when the diskette is inserted into the computer. The diskette has a square shape: in that location are apparently eight possible means to insert it into the machine, only i of which is right. What happens if I practise it wrong? I endeavor inserting the deejay sideways. Ah, the designer thought of that. A piddling study shows that the case really isn't square: it's rectangular, and then y'all tin't insert a longer side. I attempt astern. The diskette goes in only role of the way. Small-scale protrusions, indentations, and cutouts prevent the diskette from existence inserted astern or upside down: of the viii means 1 might endeavour to insert the diskette, but one is right, and only that one will fit. An splendid design.

The spindle motor from a 3½‑inch unit

Operation [edit]

How the read-write head is applied on the floppy

Visualization of magnetic information on floppy disk (image recorded with CMOS-MagView)

A spindle motor in the drive rotates the magnetic medium at a certain speed, while a stepper motor-operated mechanism moves the magnetic read/write heads radially along the surface of the deejay. Both read and write operations crave the media to be rotating and the head to contact the disk media, an activity originally achieved past a disk-load solenoid.[28] Subsequently drives held the heads out of contact until a front end-panel lever was rotated (v¼-inch) or disk insertion was complete (3½-inch). To write information, current is sent through a coil in the head as the media rotates. The caput'due south magnetic field aligns the magnetization of the particles directly below the head on the media. When the current is reversed the magnetization aligns in the opposite direction, encoding one flake of data. To read data, the magnetization of the particles in the media induce a tiny voltage in the head curl as they laissez passer nether it. This small signal is amplified and sent to the floppy disk controller, which converts the streams of pulses from the media into data, checks it for errors, and sends it to the host computer organisation.

Formatting [edit]

A bare unformatted diskette has a blanket of magnetic oxide with no magnetic order to the particles. During formatting, the magnetizations of the particles are aligned forming tracks, each broken up into sectors, enabling the controller to properly read and write data. The tracks are concentric rings around the center, with spaces between tracks where no data is written; gaps with padding bytes are provided betwixt the sectors and at the end of the track to allow for slight speed variations in the disk drive, and to permit better interoperability with disk drives connected to other similar systems.

Each sector of information has a header that identifies the sector location on the disk. A cyclic back-up check (CRC) is written into the sector headers and at the terminate of the user data so that the disk controller can observe potential errors.

Some errors are soft and tin can exist resolved by automatically re-trying the read operation; other errors are permanent and the disk controller volition signal a failure to the operating system if multiple attempts to read the data even so fail.

Insertion and ejection [edit]

After a disk is inserted, a catch or lever at the front of the drive is manually lowered to prevent the disk from accidentally emerging, appoint the spindle clamping hub, and in 2-sided drives, appoint the second read/write caput with the media.

In some v¼-inch drives, insertion of the disk compresses and locks an ejection spring which partially ejects the disk upon opening the take hold of or lever. This enables a smaller concave area for the thumb and fingers to grasp the disk during removal.

Newer five¼-inch drives and all three½-inch drives automatically engage the spindle and heads when a disk is inserted, doing the opposite with the printing of the eject push.

On Apple Macintosh computers with congenital-in 3½-inch disk drives, the ejection button is replaced past software controlling an ejection motor which but does so when the operating system no longer needs to admission the bulldoze. The user could drag the epitome of the floppy drive to the trash can on the desktop to eject the disk. In the case of a power failure or drive malfunction, a loaded deejay can be removed manually by inserting a straightened paper clip into a pocket-size hole at the bulldoze'due south front end panel, simply every bit i would do with a CD-ROM drive in a similar situation. The Sharp X68000 featured soft-eject 5¼-inch drives. Some late-generation IBM PS/2 machines had soft-eject three½-inch disk drives likewise for which some problems of DOS (i.due east. PC DOS 5.02 and college) offered an EJECT command.

Finding rails zero [edit]

Earlier a deejay tin be accessed, the drive needs to synchronize its head position with the deejay tracks. In some drives, this is accomplished with a Track Zero Sensor, while for others it involves the drive caput hit an immobile reference surface.

In either case, the caput is moved so that it is approaching track zero position of the disk. When a drive with the sensor has reached track cypher, the head stops moving immediately and is correctly aligned. For a drive without the sensor, the mechanism attempts to move the caput the maximum possible number of positions needed to reach runway goose egg, knowing that one time this motion is complete, the head will exist positioned over track zero.

Some bulldoze mechanisms such as the Apple 2 5¼-inch drive without a track zero sensor, produce characteristic mechanical noises when trying to move the heads by the reference surface. This concrete striking is responsible for the 5¼-inch drive clicking during the boot of an Apple tree 2, and the loud rattles of its DOS and ProDOS when disk errors occurred and track goose egg synchronization was attempted.

Finding sectors [edit]

All 8-inch and some five¼-inch drives used a mechanical method to locate sectors, known as either hard sectors or soft sectors, and is the purpose of the pocket-sized hole in the jacket, off to the side of the spindle hole. A calorie-free beam sensor detects when a punched hole in the disk is visible through the hole in the jacket.

For a soft-sectored disk, in that location is only a single hole, which is used to locate the first sector of each track. Clock timing is so used to find the other sectors backside it, which requires precise speed regulation of the drive motor.

For a difficult-sectored deejay, in that location are many holes, one for each sector row, plus an boosted pigsty in a one-half-sector position, that is used to indicate sector nil.

The Apple 2 reckoner arrangement is notable in that it did not take an index hole sensor and ignored the presence of hard or soft sectoring. Instead, information technology used special repeating data synchronization patterns written to the disk betwixt each sector, to assist the estimator in finding and synchronizing with the information in each track.

The later 3½-inch drives of the mid-1980s did not utilize sector alphabetize holes, but instead also used synchronization patterns.

Near iii½-inch drives used a constant speed drive motor and contain the same number of sectors across all tracks. This is sometimes referred to as Constant Angular Velocity (CAV). In order to fit more data onto a deejay, some three½-inch drives (notably the Macintosh External 400K and 800K drives) instead use Constant Linear Velocity (CLV), which uses a variable speed drive motor that spins more slowly equally the head moves away from the center of the disk, maintaining the aforementioned speed of the head(s) relative to the surface(s) of the disk. This allows more sectors to be written to the longer middle and outer tracks every bit the track length increases.

Sizes [edit]

While the original IBM 8-inch disk was actually so defined, the other sizes are defined in the metric system, their usual names being but rough approximations.[29]

Different sizes of floppy disks are mechanically incompatible, and disks can fit but 1 size of drive. Drive assemblies with both 3+ 1⁄2 -inch and 5+ i⁄4 -inch slots were available during the transition period between the sizes, but they contained two separate drive mechanisms. In addition, there are many subtle, usually software-driven incompatibilities betwixt the two. 5+ 1⁄4 -inch disks formatted for utilize with Apple Two computers would exist unreadable and treated every bit unformatted on a Commodore. As computer platforms began to form, attempts were made at interchangeability. For example, the "SuperDrive" included from the Macintosh SE to the Power Macintosh G3 could read, write and format IBM PC format 3+ 1⁄ii -inch disks, merely few IBM-compatible computers had drives that did the opposite. eight-inch, 5+ one⁄four -inch and 3+ ane⁄2 -inch drives were manufactured in a variety of sizes, most to fit standardized drive bays. Aslope the common disk sizes were non-classical sizes for specialized systems.

viii-inch floppy disk [edit]

Floppy disks of the get-go standard are 8 inches in diameter,[1] protected by a flexible plastic jacket. It was a read-only device used past IBM as a way of loading microcode.[xxx] Read/write floppy disks and their drives became available in 1972, but it was IBM's 1973 introduction of the 3740 data entry organisation[31] that began the institution of floppy disks, chosen past IBM the Diskette one, every bit an manufacture standard for information interchange. Formatted diskette for this system store 242,944 bytes.[32] Early on microcomputers used for engineering, business, or word processing often used one or more than viii-inch disk drives for removable storage; the CP/M operating system was adult for microcomputers with 8-inch drives.

The family of 8-inch disks and drives increased over time and after versions could shop up to 1.ii MB;[33] many microcomputer applications did non need that much capacity on one disk, so a smaller size disk with lower-price media and drives was feasible. The 5+ ane⁄4 -inch drive succeeded the 8-inch size in many applications, and developed to about the aforementioned storage chapters as the original 8-inch size, using college-density media and recording techniques.

5+ 1⁄4 -inch floppy disk [edit]

5¼-inch floppies, front and dorsum

Uncovered

5+ 1⁄iv ‑inch disk machinery with deejay inserted.

The head gap of an fourscore‑track loftier-density (1.2 MB in the MFM format) 5+ 1⁄4 ‑inch bulldoze (a.1000.a. Mini diskette, Mini deejay, or Minifloppy) is smaller than that of a forty‑rail double-density (360 KB if double-sided) drive simply can likewise format, read and write 40‑rail disks provided the controller supports double stepping or has a switch to do so. five+ 1⁄iv -inch 80-track drives were likewise called hyper drives.[nb 2] A blank twoscore‑rail disk formatted and written on an 80‑track drive tin be taken to its native drive without problems, and a deejay formatted on a twoscore‑track drive can be used on an 80‑track drive. Disks written on a twoscore‑track bulldoze and so updated on an 80 rails drive become unreadable on any 40‑runway drives due to track width incompatibility.

Single-sided disks were coated on both sides, despite the availability of more than expensive double sided disks. The reason usually given for the higher price was that double sided disks were certified mistake-gratis on both sides of the media. Double-sided disks could be used in some drives for single-sided disks, as long every bit an alphabetize signal was non needed. This was done one side at a time, by turning them over (flippy disks); more expensive dual-head drives which could read both sides without turning over were later produced, and somewhen became used universally.

three+ i⁄2 -inch floppy disk [edit]

Internal parts of a

3+ ane⁄2 -inch floppy disk.

  1. A hole that indicates a high-capacity disk.
  2. The hub that engages with the drive motor.
  3. A shutter that protects the surface when removed from the drive.
  4. The plastic housing.
  5. A polyester sheet reducing friction against the disk media equally it rotates inside the housing.
  6. The magnetic coated plastic deejay.
  7. A schematic representation of one sector of data on the disk; the tracks and sectors are not visible on bodily disks.
  8. The write protection tab (unlabeled) in upper left.

A

3+ 1⁄2 -inch floppy deejay drive

In the early on 1980s, many manufacturers introduced smaller floppy drives and media in diverse formats. A consortium of 21 companies eventually settled on a iii+ one⁄2 -inch design known as the Micro diskette, Micro disk, or Micro floppy, similar to a Sony design just improved to support both single-sided and double-sided media, with formatted capacities generally of 360 KB and 720 KB respectively. Single-sided drives shipped in 1983,[34] and double-sided in 1984. The double-sided, high-density 1.44 MB (actually 1440 KiB = one.41 MiB) disk bulldoze, which would become the about popular, first shipped in 1986.[35] The first Macintosh computers used single-sided iii+ 1⁄2 -inch floppy disks, but with 400 KB formatted capacity. These were followed in 1986 past double-sided 800 KB floppies. The higher capacity was achieved at the same recording density by varying the deejay-rotation speed with head position so that the linear speed of the deejay was closer to constant. Later Macs could also read and write 1.44 MB Hard disk drive disks in PC format with stock-still rotation speed. Higher capacities were similarly achieved by Acorn'due south RISC OS (800 KB for DD, 1,600 KB for HD) and AmigaOS (880 KB for DD, 1,760 KB for Hd).

All 3+ ane⁄two -inch disks take a rectangular hole in i corner which, if obstructed, write-enables the deejay. A sliding detented piece can exist moved to block or reveal the part of the rectangular hole that is sensed by the bulldoze. The Hd 1.44 MB disks take a second, unobstructed pigsty in the opposite corner that identifies them equally being of that capacity.

In IBM-uniform PCs, the three densities of 3+ one⁄ii -inch floppy disks are backwards-uniform; higher-density drives can read, write and format lower-density media. It is also possible to format a disk at a lower density than that for which information technology was intended, but but if the deejay is first thoroughly demagnetized with a bulk eraser, as the loftier-density format is magnetically stronger and volition prevent the deejay from working in lower-density modes.

Writing at dissimilar densities than those at which disks were intended, sometimes by altering or drilling holes, was possible just not supported by manufacturers. A hole on 1 side of a 3+ 1⁄2 -inch disk can be altered as to make some disk drives and operating systems treat the disk as one of college or lower density, for bidirectional compatibility or economic reasons.[ clarification needed ] [36] [37] Some computers, such as the PS/2 and Acorn Archimedes, ignored these holes altogether.[38]

Other sizes [edit]

Other smaller floppy sizes were proposed, peculiarly for portable or pocket-sized devices that needed a smaller storage device.

  • three¼-inch floppies otherwise like to five¼-inch floppies were proposed by Tabor and Dysan.
  • Three-inch disks similar in construction to three½-inch were manufactured and used for a time, particularly by Amstrad computers and word processors.
  • A two-inch nominal size known every bit the Video Floppy was introduced by Sony for utilise with its Mavica still video camera. [39]
  • An incompatible two-inch floppy produced by Fujifilm called the LT-1 was used in the Zenith Minisport portable reckoner. [40]

None of these sizes achieved much market success.[41]

Sizes, performance and capacity [edit]

Floppy disk size is often referred to in inches, even in countries using metric and though the size is defined in metric. The ANSI specification of three+ ane⁄ii -inch disks is entitled in role "ninety mm (3.5-inch)" though 90 mm is closer to 3.54 inches.[42] Formatted capacities are mostly set in terms of kilobytes and megabytes.

Historical sequence of floppy disk formats
Disk format Twelvemonth introduced Formatted storage capacity Marketed capacity
viii-inch: IBM 23FD (read-only) 1971 81.664 kB[43] non marketed commercially
8-inch: Memorex 650 1972 175 kB[44] ane.5 megabit full runway[44]
eight-inch: SS SD

IBM 33FD / Shugart 901

1973 242.844 kB[43] 3.1 megabit unformatted
8-inch: DS SD

IBM 43FD / Shugart 850

1976 568.320 kB[43] six.2 megabit unformatted
5+ 1⁄iv -inch (35 runway) Shugart SA 400 1976[45] 87.five KB[46] 110 kB
viii-inch DS DD

IBM 53FD / Shugart 850

1977 962–1,184 KB depending upon sector size 1.2 MB
5+ ane⁄iv -inch DD 1978 360 or 800 KB 360 KB
five+ ane⁄4 -inch Apple Disk 2 (Pre-DOS 3.3) 1978 113.75 KB (256 byte sectors, 13 sectors/rails, 35 tracks) 113 KB
five+ 1⁄four -inch Atari DOS 2.0S 1979 90 KB (128 byte sectors, xviii sectors/runway, 40 tracks) xc KB
5+ 1⁄iv -inch Commodore DOS one.0 (SSDD) 1979[47] 172.five KB[48] 170 KB
5+ 1⁄4 -inch Commodore DOS 2.1 (SSDD) 1980[49] 170.75 KB[48] 170 KB
5+ one⁄4 -inch Apple Disk II (DOS three.3) 1980 140 KB (256 byte sectors, sixteen sectors/track, 35 tracks) 140 KB
5+ 1⁄four -inch Apple tree Disk 2 (Roland Gustafsson'southward RWTS18) 1988 157.5 KB (768 byte sectors, 6 sectors/rail, 35 tracks) Game publishers privately contracted third party custom DOS.
five+ one⁄4 -inch Victor 9000 / ACT Sirius 1 (SSDD) 1982[50] 612 KB (512 byte sectors, 11-xix variable sectors / rails, eighty tracks) 600 KB
5+ one⁄4 -inch Victor 9000 / Human activity Sirius 1 (DSDD) 1982[51] 1196 KB (512 byte sectors, 11-19 variable sectors / rail, eighty tracks) 1200 KB
iii+ one⁄2 -inch HP SS 1982 280 KB (256 byte sectors, 16 sectors/track, lxx tracks) 264 KB
5+ ane⁄4 -inch Atari DOS 3 1983 127 KB (128 byte sectors, 26 sectors/rail, 40 tracks) 130 KB
three-inch 1982[52] [53] ? 125 KB (SS/SD),

500 KB (DS/DD)[53]

3+ i⁄ii -inch SS DD (at release) 1983 360 KB (400 KB on Macintosh) 500 KB
3+ 1⁄2 -inch DS DD 1983 720 KB (800 KB on Macintosh and RISC Bone,[54] 880 KB on Amiga) 1 MB
5+ 1⁄4 -inch QD 1980[55] 720 KB 720 KB
5+ 1⁄iv -inch RX50 (SSQD) circa 1982 — 400 KB
5+ 1⁄4 -inch HD 1982[56] ane,200 KB 1.2 MB
3-inch Mitsumi Quick Disk 1985 128 to 256 KB ?
three-inch Famicom Disk System (derived from Quick Disk) 1986 112 KB 128 KB[57]
two-inch 1989 720 KB[58] ?
2+ 1⁄2 -inch Abrupt CE-1600F,[59] CE-140F (chassis: FDU-250, medium: CE-1650F)[lx] 1986[59] [60] [61] turnable diskette with 62,464 bytes per side (512 byte sectors, viii sectors/track, 16 tracks, GCR (4/five) recording)[59] [60] two× 64 KB (128 KB)[59] [threescore]
5+ 1⁄four -inch[62] Perpendicular 1986[61] 100 KB per inch[61] ?
3+ 1⁄2 -inch Hd 1986[63] 1,440 KB (ane,760 KB on Amiga) ane.44 MB (two.0 MB unformatted)
3+ one⁄2 -inch Hard disk 1987 one,600 KB on RISC Bone[54] i.6 MB
three+ 1⁄2 -inch ED 1987[64] 2,880 KB (3,200 KB on Sinclair QL) two.88 MB
3+ 1⁄2 -inch Floptical (LS) 1991 20,385 KB 21 MB
3+ i⁄two -inch SuperDisk (LS-120) 1996 120.375 MB 120 MB
3+ one⁄ii -inch SuperDisk (LS-240) 1997 240.75 MB 240 MB
3+ 1⁄2 -inch HiFD 1998/99 ? 150/200 MB
Abbreviations: SD = Single Density; DD = Double Density; QD = Quad Density; Hard disk drive = High Density; ED = Extra-loftier Density; [65] [66] [67] [68] [69] LS = Laser Servo; HiFD = High capacity Floppy Disk; SS = Single Sided; DS = Double Sided
Formatted storage capacity is total size of all sectors on the disk:
  • For 8-inch run across List of floppy disk formats#IBM 8-inch formats. Spare, hidden and otherwise reserved sectors are included in this number.
  • For 5+ 1⁄four - and three+ ane⁄2 inch capacities quoted are from subsystem or organization vendor statements.

Marketed chapters is the capacity, typically unformatted, by the original media OEM vendor or in the case of IBM media, the first OEM thereafter. Other formats may get more or less chapters from the same drives and disks.

A box of virtually 80 floppy disks together with one USB memory stick. The stick is capable of holding over 130 times as much data as the entire box of disks put together.

Data is by and large written to floppy disks in sectors (angular blocks) and tracks (concentric rings at a constant radius). For example, the Hard disk drive format of three½-inch floppy disks uses 512 bytes per sector, 18 sectors per rail, 80 tracks per side and two sides, for a total of i,474,560 bytes per disk.[70] [ failed verification ] Some disk controllers can vary these parameters at the user's request, increasing storage on the disk, although they may not be able to be read on machines with other controllers. For example, Microsoft applications were often distributed on 3+ ane⁄2 -inch 1.68 MB DMF disks formatted with 21 sectors instead of xviii; they could still exist recognized past a standard controller. On the IBM PC, MSX and nigh other microcomputer platforms, disks were written using a constant angular velocity (CAV) format,[64] with the deejay spinning at a constant speed and the sectors belongings the aforementioned amount of information on each track regardless of radial location.

Because the sectors have constant athwart size, the 512 bytes in each sector are compressed more near the deejay'southward centre. A more space-efficient technique would be to increase the number of sectors per track toward the outer edge of the disk, from 18 to 30 for example, thereby keeping nearly constant the amount of concrete disk space used for storing each sector; an example is zone fleck recording. Apple tree implemented this in early Macintosh computers past spinning the deejay more than slowly when the head was at the border, while maintaining the information rate, allowing 400 KB of storage per side and an extra lxxx KB on a double-sided disk.[71] This higher capacity came with a disadvantage: the format used a unique drive machinery and control circuitry, meaning that Mac disks could non be read on other computers. Apple eventually reverted to constant angular velocity on Hard disk drive floppy disks with their after machines, still unique to Apple tree as they supported the older variable-speed formats.

Deejay formatting is usually washed by a utility plan supplied by the calculator Bone manufacturer; generally, it sets up a file storage directory system on the deejay, and initializes its sectors and tracks. Areas of the disk unusable for storage due to flaws can be locked (marked every bit "bad sectors") and then that the operating arrangement does non attempt to use them. This was time-consuming then many environments had quick formatting which skipped the mistake checking process. When floppy disks were often used, disks pre-formatted for pop computers were sold. The unformatted capacity of a floppy deejay does not include the sector and track headings of a formatted disk; the deviation in storage between them depends on the drive's application. Floppy deejay drive and media manufacturers specify the unformatted capacity (for example, ii MB for a standard 3+ ane⁄2 -inch HD floppy). It is unsaid that this should not be exceeded, since doing so volition near likely outcome in performance problems. DMF was introduced permitting one.68 MB to fit onto an otherwise standard three+ 1⁄2 -inch disk; utilities then appeared allowing disks to exist formatted equally such.

Mixtures of decimal prefixes and binary sector sizes crave care to properly summate total chapters. Whereas semiconductor memory naturally favors powers of two (size doubles each time an address pin is added to the integrated circuit), the capacity of a deejay drive is the production of sector size, sectors per track, tracks per side and sides (which in hard disk drives with multiple platters tin be greater than 2). Although other sector sizes have been known in the past, formatted sector sizes are now almost always gear up to powers of two (256 bytes, 512 bytes, etc.), and, in some cases, deejay capacity is calculated equally multiples of the sector size rather than only in bytes, leading to a combination of decimal multiples of sectors and binary sector sizes. For example, ane.44 MB 3+ 1⁄2 -inch HD disks have the "Grand" prefix peculiar to their context, coming from their capacity of 2,880 512-byte sectors (i,440 KiB), consistent with neither a decimal megabyte nor a binary mebibyte (MiB). Hence, these disks hold ane.47 MB or 1.41 MiB. Usable data capacity is a role of the disk format used, which in plow is adamant by the FDD controller and its settings. Differences between such formats tin can result in capacities ranging from approximately 1300 to 1760 KiB (1.80 MB) on a standard iii+ 1⁄two -inch loftier-density floppy (and upwards to nearly two MB with utilities such as 2M/2MGUI). The highest capacity techniques require much tighter matching of bulldoze head geometry between drives, something not e'er possible and unreliable. For example, the LS-240 bulldoze supports a 32 MB capacity on standard 3+ 1⁄ii -inch HD disks,[72] but this is a write-in one case technique, and requires its own drive.

The raw maximum transfer rate of 3+ 1⁄2 -inch ED floppy drives (2.88 MB) is nominally i,000 kilobits/southward, or approximately 83% that of single-speed CD‑ROM (71% of sound CD). This represents the speed of raw data $.25 moving nether the read head; however, the effective speed is somewhat less due to space used for headers, gaps and other format fields and can be even further reduced by delays to seek between tracks.

See also [edit]

  • Berg connector for 3½-inch floppy drive
  • dd (Unix)
  • Disk paradigm
  • Don't Copy That Floppy
  • Floppy disk controller
  • Floppy disk hardware emulator
  • Floppy disk variants
  • Hd
  • History of the floppy disk
  • Shugart jitney – popular mainly for viii-inch drives, and partially for five¼-inch
  • XDF
  • VGA-Copy copy tool (retries on errors, over-formatted floppies), DOS, discontinued
  • Zip bulldoze

Notes [edit]

  1. ^ The cost of a hd with a controller in the mid 1980s was thousands of dollars, for chapters of 80 MB or less.
  2. ^ "Hyper bulldoze" was an alternative proper noun for five¼-inch lxxx-track HD floppy drives with one.2 MB capacity. The term was used f.due east. past Philips Austria for their Philips :Yes and Digital Research in conjunction with DOS Plus.

References [edit]

  1. ^ a b c Teja, Edward R. (1985). The Designer's Guide to Disk Drives (1st ed.). Reston, Virginia, USA: Reston / Prentice hall. ISBN0-8359-1268-X.
  2. ^ a b Fletcher, Richard (30 January 2007). "PC World Announces the End of the Floppy Disk". The Daily Telegraph. Archived from the original on ii January 2012. Retrieved 2 Baronial 2020.
  3. ^ "1971: Floppy disk loads mainframe calculator information". Computer History Museum. Computer History Museum. Archived from the original on 8 Dec 2015. Retrieved 1 December 2015.
  4. ^ "Five decades of disk drive industry firsts". Archived from the original on 26 July 2011. Retrieved 15 October 2012.
  5. ^ IBM's 370/145 Uncovered; Interesting Curves Revealed, Datamation, November 1, 1970
  6. ^ Watson (24 May 2010). "The Floppy Disk". Canadian Business organization. Vol. 83, no. eight. p. 17.
  7. ^ Porter, James (November 1992). 1992 Disk/Trend Report - Flexible Disk Drives (Report). p. DT14-iii.
  8. ^ a b c "The Microfloppy—One Key to Portability", Thomas R. Jarrett, Computer Technology Review, winter 1983 (Jan 1984), pp. 245–7
  9. ^ Picture show of disk
  10. ^ 1991 Deejay/Tendency Written report, Flexible Disk Drives, Figure 2
  11. ^ Reinhardt, Andy (12 August 1996). "Iomega'southward Zip drives need a fleck more zip". Concern Calendar week. No. 33. The McGraw-Hill Companies. ISSN 0007-7135. Archived from the original on 6 July 2008.
  12. ^ "floppy". LinuxCommand.org. iv January 2006. Archived from the original on 27 July 2011. Retrieved 22 June 2011.
  13. ^ Spring, Tom (24 July 2002). "What Has Your Floppy Drive Done for You Lately? PC makers are yet continuing by floppy drives despite vanishing consumer demand". PC Earth. Archived from the original on 24 December 2011. Retrieved 4 April 2012.
  14. ^ "R.I.P. Floppy Disk". BBC News. 1 Apr 2003. Archived from the original on xvi February 2009. Retrieved 19 July 2011.
  15. ^ Derbyshire, David (30 January 2007). "Floppy disks ejected as demand slumps". The Daily Telegraph. Archived from the original on 22 May 2011. Retrieved 19 July 2011.
  16. ^ "Federal Agencies Need to Accost Aging Legacy Systems" (PDF). Report to Congressional Requesters. U.s.a. Regime Accountability Office. May 2016. Archived (PDF) from the original on 2 June 2016. Retrieved 26 May 2016.
  17. ^ Trujillo, Mario (25 May 2016). "US nuclear emergency messaging organisation still uses floppy disks". The Colina. Archived from the original on 29 May 2016. Retrieved 30 May 2016.
  18. ^ "How to use Floppy Disk on Windows 10". nine March 2016. Archived from the original on 17 Nov 2018. Retrieved 11 June 2019.
  19. ^ Warren, Tom (11 August 2020). "Boeing 747s still go disquisitional updates via floppy disks: A rare expect inside a 20-year-old airliner". The Verge. Vox Media. Retrieved 26 Feb 2021.
  20. ^ "Notice of Termination of Sales of 3.5-inch Floppy Disks". 23 April 2010. Retrieved 14 September 2022.
  21. ^ SORREL, CHARLIE (26 April 2010). "Sony Announces the Death of the Floppy Disk". Retrieved 14 September 2022.
  22. ^ Robinson, Dan (20 September 2022). "'Last man standing in the floppy disk business' reckons his company has 4 years left". The Register. Retrieved 23 September 2022.
  23. ^ Hilkmann, Niek; Walskaar, Thomas (12 September 2022). "We Spoke With the Concluding Person Standing in the Floppy Deejay Business". Retrieved xiv September 2022. Turns out the obsolete floppy is way more than in need than you lot'd think
  24. ^ Landphair, Ted (10 March 2007). "So Long, Faithful Floppies". VOA News. Voice of America. Archived from the original on 10 Oct 2016. Retrieved 25 Dec 2008.
  25. ^ "The Disk II". Apple tree II History. two December 2008. Archived from the original on 19 February 2018. Retrieved 17 Feb 2018. Wozniak'south technique would allow the drive to do self-synchronization ("soft sectoring"), non have to deal with that trivial timing hole, and save on hardware.
  26. ^ (M)Tronics SCS (twenty May 2007). "Floppy-Disketten-Laufwerke" [Floppy deejay drives] (in German). Archived from the original on 19 June 2017. Retrieved 19 June 2017.
  27. ^ Norman, Donald (1990). "Chapter i". The Design of Everyday Things. New York, United states of america: Doubleday. ISBN0-385-26774-6.
  28. ^ Porter, Jim, ed. (2005). "Oral History Panel on eight inch Floppy Disk Drives" (PDF). p. iv. Archived from the original (PDF) on 13 May 2015. Retrieved 22 June 2011.
  29. ^ X3.162, ANSI, 1994, Information Systems – Unformatted Flexible Disk Cartridge for Information Interchange, 5.25 in (130 mm), 96 Tracks per inch (3.8 Tracks per Millimeter), General, Physical, and Magnetic Requirements (includes ANSI X3.162/TC-one-1995) Specifies the general, physical, and magnetic requirements for interchangeability for the two-sided, five.25 in (130 mm) flexible disk cartridge
  30. ^ "Floppy Disk". Louisiana Land Academy. Archived from the original on 18 Oct 2014. Retrieved two December 2013.
  31. ^ "3740". Archives. IBM. 23 Jan 2003. Archived from the original on 25 December 2017. Retrieved 13 Oct 2014.
  32. ^ IBM 3740 Data Entry System System Summary and Installation Manual – Physical Planning (PDF). IBM. 1974. p. 2. Archived (PDF) from the original on xv February 2017. Retrieved vii March 2019 – via Stuttgart University. The diskette is nigh viii" (20 cm) square and has a net chapters of 1898 128-character records – about ane twenty-four hours's data entry activity. Each of the diskette's 73 magnetic recording tracks available for data entry can hold 26 sectors of up to 128 characters each.
  33. ^ "The IBM Diskette Full general Information Manual". DE: Z80. Archived from the original on 28 Oct 2014. Retrieved xiii October 2014.
  34. ^ Shea, Tom (13 June 1983). "Shrinking drives increase storage". InfoWorld. pp. 1, vii, 8, nine, 11. Shugart is one of the major subscribers to the iii1⁄2-inch micro-floppy standard, along with Sony and 20 other company ... Its single-sided SA300 micro-floppy bulldoze offers 500K of unformatted storage. Shugart's Kevin Burr said the obvious next pace is to put another 500K of storage on the other side of the diskette and that the firm volition come out with a double-sided 1-megabyte micro-floppy bulldoze soon.
  35. ^ 1986 Disk/Trend Report – Flexible Disk Drives. Disk/Trend, Inc. Nov 1986. p. FSPEC-59. Reports Sony shipped in 1Q 1986
  36. ^ "Managing Disks". Archived from the original on 24 May 2006. Retrieved 25 May 2006.
  37. ^ "A question of floppies". Archived from the original on ane October 2011. Retrieved 20 February 2011.
  38. ^ "Formatting 720K Disks on a 1.44MB Floppy". Floppy Drive. Archived from the original on 23 July 2011. Retrieved xi Feb 2011.
  39. ^ "Sony / Canon ii Inch Video Floppy". Museum of Obsolete Media. 2 May 2013. Archived from the original on 13 January 2018. Retrieved 4 Jan 2018.
  40. ^ "two inch lt1 floppy deejay". Museum of Obsolete Media. 22 July 2017. Archived from the original on 4 January 2018. Retrieved 4 Jan 2018.
  41. ^ Disk/Trend Study-Flexible Disk Drives, Deejay/Trend Inc., November 1991, pp. SUM-27
  42. ^ ANSI X3.137, 1- and Two-Sided, Unformatted, ninety-mm (3.5-inch) v,3-tpmm (135-tpi), Flexible Disk Cartridge for 7958 bpr Use. Full general, Physical and Magnetic Requirements.
  43. ^ a b c Engh, James T. (September 1981). "The IBM Diskette and Diskette Drive". IBM Periodical of Research and Evolution. 25 (5): 701–710. doi:10.1147/rd.255.0701.
  44. ^ a b "Memorex 650 Flexible Disc File" (PDF). Archived from the original (PDF) on 25 July 2011. Retrieved 22 June 2011.
  45. ^ Sollman, George (July 1978). "Evolution of the Minifloppy Product Family". IEEE Transactions on Magnetics. 14 (4): 160–66. doi:10.1109/TMAG.1978.1059748. ISSN 0018-9464. S2CID 32505773.
  46. ^ "Shugart SA 400 Datasheet". Swtpc. 25 June 2007. Archived from the original on 27 May 2014. Retrieved 22 June 2011.
  47. ^ Beals, Gene (n.d.). "New Commodore Products: A Quick Review" (PDF). PET User Notes. Vol. two, no. i. Montgomeryville, Pennsylvania. p. ii. Archived (PDF) from the original on eleven June 2016. Retrieved 7 October 2018.
  48. ^ a b W, Raeto Collin (January 1982). Programming the PET/CBM: The Reference Encyclopedia For Commodore PET & CBM Users. COMPUTE! Books. p. 167. ISBN0-942386-04-3 . Retrieved 7 October 2018.
  49. ^ Commodore Business Machines (five February 1980). "cbmsrc / DOS_4040 / dos". GitHub . Retrieved vii October 2018.
  50. ^ "Victor 9000 Hardware Reference Manual" (PDF). Archived (PDF) from the original on 29 January 2022. Retrieved 12 September 2022.
  51. ^ "Victor 9000 Hardware Reference Manual" (PDF). Archived (PDF) from the original on 29 January 2022. Retrieved 12 September 2022.
  52. ^ "Chronology of Events in the History of Microcomputers − 1981–1983 Business Takes Over". Archived from the original on 7 Dec 2008. Retrieved 4 October 2008.
  53. ^ a b "Three-inch floppy disk product announced" (PDF). Archived from the original (PDF) on viii August 2012. Retrieved 4 October 2008.
  54. ^ a b "vi. Using floppy and hard discs". RISC OS 3.7 User Guide. 21 January 1997. Retrieved four Jan 2022. [ permanent dead link ]
  55. ^ Porter, James (Dec 1982). 1982 Disk/Trend Report – Flexible Deejay Drives. Disk/Trend. p. DT13-3. The original 48 tpi drives were joined by 96tpi drives from Tandon, Micro Peripherals and Micropolis in 1980 ...
  56. ^ 1986 Disk/Trend Report, Flexible Disk Drives
  57. ^ "Revisiting the Famicom Deejay Arrangement". Eurogamer. 27 July 2019. {{cite web}}: CS1 maint: url-status (link)
  58. ^ "Viability of 2-Inch Media Standard for PCs in Doubtfulness". InfoWorld. 11 (31): 21. 31 July 1989.
  59. ^ a b c d "Model CE-1600F" (PDF). Sharp PC-1600 Service Manual. Yamatokoriyama, Japan: Abrupt Corporation, Data Systems Grouping, Quality & Reliability Control Eye. July 1986. pp. 98–104. Archived (PDF) from the original on 23 March 2017. Retrieved 12 March 2017.
  60. ^ a b c d Precipitous Service Transmission Model CE-140F Pocket Disk Bulldoze (PDF). Sharp Corporation. 00ZCE140F/SME. Archived (PDF) from the original on 11 March 2017. Retrieved 11 March 2017.
  61. ^ a b c Bateman, Selby (March 1986). "The Time to come of Mass Storage". COMPUTE!. No. 70. COMPUTE! Publications, Inc. p. 18. Archived from the original on 1 July 2018. Retrieved 7 October 2018.
  62. ^ JP S6344319A, Kitagami, Osamu & Fujiwara, Hideo, "Production of perpendicular magnetic recording medium", published 1988-02-25, assigned to Hitachi Maxell
  63. ^ "Vendor Introduces Ultra High-Density Floppy Disk Media". InfoWorld. 8 (45): 19. x November 1986.
  64. ^ a b Mueller, Scott (2004). Upgrading and Repairing PCs, 15th Anniversary Edition. Que Publishing. p. 1380. ISBN0-7897-2974-1 . Retrieved 16 July 2011.
  65. ^ Mueller, Scott (1994). Hardware-Praxis – PCs warten reparieren, aufrüsten und konfigurieren (in German) (3rd ed.). Addison-Wesley Publishing Company. p. 441. ISBNthree-89319-705-2.
  66. ^ Inc, InfoWorld Media Grouping (14 Oct 1991). "InfoWorld". InfoWorld Media Group, Inc. – via Google Books.
  67. ^ Shah, Katen A. (1996) [September 1992, Apr 1992]. Intel 82077SL for Super-Dense Floppies (PDF) (Application Note) (ii ed.). Intel Corporation, IMD Marketing. AP-358, 292093-002. Archived (PDF) from the original on 19 June 2017. Retrieved nineteen June 2017.
  68. ^ Inc, Ziff Davis (10 September 1991). "PC Magazine". Ziff Davis, Inc. – via Google Books.
  69. ^ Inc, InfoWorld Media Group (19 March 1990). "InfoWorld". InfoWorld Media Group, Inc. – via Google Books.
  70. ^ "Affiliate eight: Floppy Disk Drives" (PDF). Archived (PDF) from the original on 27 January 2012. Retrieved 16 July 2011.
  71. ^ "The Original Macintosh". Folklore. Archived from the original on five December 2013. Retrieved 3 December 2013.
  72. ^ "Backdrop of Storage Systems". Mt. San Antonio College. Archived from the original on 7 December 2013.

Further reading [edit]

  • Weyhrich, Steven (2005). "The Disk II": A detailed essay describing ane of the kickoff commercial floppy disk drives (from the Apple Two History website).
  • Immers, Richard; Neufeld, Gerald G. (1984). Inside Commodore DOS: The Complete Guide to the 1541 Disk Operating System. Datamost & Reston Publishing Company (Prentice-Hall). ISBN 0-8359-3091-2.
  • Englisch, Lothar; Szczepanowski, Norbert (1984). The Beefcake of the 1541 Disk Drive. One thousand Rapids, Michigan, United states of america, Abacus Software (translated from the original 1983 German language edition, Düsseldorf, Data Becker GmbH). ISBN 0-916439-01-1.
  • Hewlett Packard: 9121D/South Disc Retentiveness Operator'southward Manual; printed 1 September 1982; role number 09121-90000.

External links [edit]

Wikimedia Commons has media related to Diskette.

  • HowStuffWorks: How Floppy Disk Drives Work
  • Computer Hope: Information almost estimator floppy drives
  • NCITS (mention of ANSI X3.162 and X3.171 floppy standards)
  • Floppy disk drives and media technical data
  • The Floppy User Guide -historical technical fabric
  • Summary of Floppy Disk Types and Specifications

Floppy Disk 5 1 4 Usb,

Source: https://en.wikipedia.org/wiki/Floppy_disk

Posted by: jameshinet1956.blogspot.com

0 Response to "Floppy Disk 5 1 4 Usb"

Post a Comment

Subscribe to: Post Comments (Atom)

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel