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] ]
] data exchange port.]] ] port in which a ] is connected.]]


A '''floppy disk hardware emulator''' is a device that emulates a mechanical ] drive with a ] or network ] that is ] with the drive it replaces, similar to how ]s replace mechanical ]s. A '''floppy disk hardware emulator''' or '''semi-virtual diskette''' (SVD) is a device that emulates a ] drive with a ] or network ] that is ] with the drive it replaces, similar to how ]s replace mechanical ]s.


== History == == History ==


Older models of ]s, ] and ] often used floppy disk drives for data transfer. Older equipment may be difficult to replace or upgrade because of cost, requirement for continuous availability or unavailable upgrades. Proper operation may require ], software and data to be read and written from and to floppies, forcing users maintain floppy drives on supporting systems.<ref></ref> Older models of ]s, ]s and ] often used floppy disk drives for data transfer. Older equipment may be difficult to replace or upgrade because of cost, requirement for continuous availability or unavailable upgrades. Proper operation may require ], software and data to be read and written from and to floppies, forcing users to maintain floppy drives on supporting systems.<ref>{{Cite web|url=https://www.techrepublic.com/article/techrepublic-tutorial-dont-be-too-quick-to-dump-the-floppy/|title=Don't be too quick to dump the floppy|last=Hardin|first=Ken|date=March 18, 2003|website=]|archive-url=https://web.archive.org/web/20180614083012/https://www.techrepublic.com/article/techrepublic-tutorial-dont-be-too-quick-to-dump-the-floppy/|archive-date=June 14, 2018|url-status=live}}</ref>


Floppy disks and floppy drives are gradually going out of production<ref></ref><ref></ref><ref>] (3M), and Maxell]</ref><ref></ref><ref></ref> and replacement of malfunctioning drives, and the systems hosting them, is becoming increasingly difficult. Floppy disks themselves are fragile, or may need to be replaced often. An alternative is to use a floppy disk hardware emulator, a device which appears to be a standard floppy drive to the old equipment by interfacing directly to the ], while storing data in another medium such as a ], ], or a ] on a computer network. Emulators can also be used as a higher-performance replacement for mechanical floppy disk drives. Floppy disks and floppy drives are gradually going out of production,<ref>{{Cite news|url=http://news.bbc.co.uk/2/hi/technology/6314251.stm|title=PC World says farewell to floppy|date=January 30, 2007|work=]|archive-url=https://web.archive.org/web/20180216222934/http://news.bbc.co.uk/2/hi/technology/6314251.stm|archive-date=February 16, 2018|url-status=live}}</ref><ref>{{Cite news|url=http://news.bbc.co.uk/2/hi/uk_news/2905953.stm|title=R.I.P. Floppy Disk|date=April 1, 2003|work=]|archive-url=https://web.archive.org/web/20180719111950/http://news.bbc.co.uk/2/hi/uk_news/2905953.stm|archive-date=July 19, 2018|url-status=live}}</ref><ref>{{Cite web |url=http://www.reghardware.com/2010/04/26/sony_stops_selling_floppies/ |title=3.5-inch floppy still available from Verbatim, &#91;&#91;Imation&#93;&#93; (3M), and Maxell |access-date=2011-11-24 |archive-url=https://web.archive.org/web/20101130145956/http://www.reghardware.com/2010/04/26/sony_stops_selling_floppies/ |archive-date=2010-11-30 |url-status=dead }}</ref><ref>{{Cite web|url=https://geeknewscentral.com/2010/04/26/tribute-to-floppy-disk-as-sony-discontinues-production/|title=Tribute to Floppy Disk as Sony discontinues production|last=Powers|first=Jeffrey|date=April 26, 2010|website=Geek News Central|archive-url=https://web.archive.org/web/20100501204759/https://geeknewscentral.com/2010/04/26/tribute-to-floppy-disk-as-sony-discontinues-production/|archive-date=May 1, 2010|url-status=live}}</ref> and replacement of malfunctioning drives, and the systems hosting them, is becoming increasingly difficult. Floppy disks themselves are fragile, or may need to be replaced often. An alternative is to use a floppy disk hardware emulator, a device which appears to be a standard floppy drive to the old equipment by interfacing directly to the ], while storing data in another medium such as a ], ], or a ] on a computer network. Emulators can also be used as a higher-performance replacement for mechanical floppy disk drives.


== Emulation process == == Emulation process ==


A typical floppy disk controller sends an ] / ] / ] encoded signal to the drive to write data, and expects a similar signal returned when reading the drive.<ref></ref> On a write, a hardware ] or a software-based filter component undoes the encoding, and stores the sector data as logically written by the host. An inverse mechanism translates the stored data back into an encoded signal when the data is read. Noisy raw data signals are filtered and cleaned up before conversion. A typical floppy disk controller sends an ] / ] / ] encoded signal to the drive to write data, and expects a similar signal returned when reading the drive.<ref>{{Cite book|url=http://www.lintech.org/comp-per/07MAGREC.pdf|title=Computer Peripherals|publisher=Nanyang Technological University|location=Singapore|publication-date=October 16, 2001|chapter=Magnetic Recording Fundamentals|archive-url=https://web.archive.org/web/20181002001916/http://www.lintech.org/comp-per/07MAGREC.pdf|archive-date=October 2, 2018|url-status=live}}</ref> On a write, a hardware ] or a software-based filter component undoes the encoding, and stores the sector data as logically written by the host. An inverse mechanism translates the stored data back into an encoded signal when the data is read. Noisy raw data signals are filtered and cleaned up before conversion.


Most FDC interfaces do not directly address tracks, rather provide "step-in" and "step-out" pulses. Those, and the current sector number virtually rotating under the emulated read/write head, are tracked by the emulator in order to determine which sector is to be accessed.<ref></ref><ref></ref> Most FDC interfaces do not directly address tracks; instead they provide "step-in" and "step-out" pulses. Those, and the current sector number virtually rotating under the emulated read/write head, are tracked by the emulator in order to determine which sector is to be accessed.<ref>{{Cite web|url=http://www.hermannseib.com/documents/floppy.pdf|title=The floppy user guide|last=Haardt|first=Michael|last2=Knaff|first2=Alain|date=June 11, 2001|archive-url=https://web.archive.org/web/20190213173042/http://www.hermannseib.com/documents/floppy.pdf|archive-date=February 13, 2019|url-status=live|last3=Niemi|first3=David C.}}</ref><ref>{{Cite web|url=http://www.pcguide.com/ref/fdd/index.htm|title=Floppy Disk Drives|last=Kozierok|first=Charles M.|website=The PC Guide|archive-url=https://web.archive.org/web/20010304025138/http://www.pcguide.com/ref/fdd/index.htm|archive-date=March 4, 2001|url-status=dead}}</ref>


Because the interface to the floppy drive is very low-level, emulators must maintain the approximate timing of floppy disk operations. This may require the emulator to provide buffering, with some delay in updating the permanent storage. Because the interface to the floppy drive is very low-level, emulators must maintain the approximate timing of floppy disk operations. This may require the emulator to provide buffering, with some delay in updating the permanent storage.


The emulator saves the data written to the floppy in either local storage (stand-alone emulators), or in a remote storage device or data exchange module (stateless emulators). The emulator saves the data written to the floppy in either local storage (stand-alone emulators), or in a remote storage device or data exchange module (stateless emulators).
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* Direct access to some dedicated ] (e.g.: a 1.44MB partition on a USB key) * Direct access to some dedicated ] (e.g.: a 1.44MB partition on a USB key)
* Floppy file system translation (e.g.: FAT12 floppy ↔ USB key folder) * Floppy file system translation (e.g.: FAT12 floppy ↔ USB key folder)
* ISO floppy ]s (e.g.: raw floppy ↔ .iso USB key file) * Floppy ]s (e.g.: raw floppy ↔ .img/.iso USB key file)


''Direct access'' and ''ISO image'' implementations can also emulate system / non-standard floppies, whose file system can't be simply translated. ''Direct access'' and ''floppy image'' implementations can also emulate system / non-standard floppies, whose file system can't be simply translated.


''ISO image'' implementation can also be coupled with a ] to seamlessly emulate floppy drives on a computer. ''Floppy image'' implementation can also be coupled with a ] to seamlessly emulate floppy drives on a computer.


Some devices can store multiple floppy images, and provide a mechanism to select which emulated floppy is mounted on the emulated drive. Some devices can store multiple floppy images, and provide a mechanism to select which emulated floppy is mounted on the emulated drive.
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== References == == References ==


{{refs}} {{reflist}}


== See also == == See also ==


* ]
* ] * ]
* ] * ]
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] ]
]
] ]
] ]

Latest revision as of 19:09, 27 July 2024

A floppy disk hardware emulator for a 3½ drive.
The front of an emulator, showing the USB port in which a flash drive is connected.

A floppy disk hardware emulator or semi-virtual diskette (SVD) is a device that emulates a floppy disk drive with a solid state or network storage device that is plug compatible with the drive it replaces, similar to how solid-state drives replace mechanical hard disk drives.

History

Older models of computers, electronic musical instruments and industrial automation often used floppy disk drives for data transfer. Older equipment may be difficult to replace or upgrade because of cost, requirement for continuous availability or unavailable upgrades. Proper operation may require operating system, software and data to be read and written from and to floppies, forcing users to maintain floppy drives on supporting systems.

Floppy disks and floppy drives are gradually going out of production, and replacement of malfunctioning drives, and the systems hosting them, is becoming increasingly difficult. Floppy disks themselves are fragile, or may need to be replaced often. An alternative is to use a floppy disk hardware emulator, a device which appears to be a standard floppy drive to the old equipment by interfacing directly to the floppy disk controller, while storing data in another medium such as a USB thumb drive, Secure Digital card, or a shared drive on a computer network. Emulators can also be used as a higher-performance replacement for mechanical floppy disk drives.

Emulation process

A typical floppy disk controller sends an MFM / FM / GCR encoded signal to the drive to write data, and expects a similar signal returned when reading the drive. On a write, a hardware PLL or a software-based filter component undoes the encoding, and stores the sector data as logically written by the host. An inverse mechanism translates the stored data back into an encoded signal when the data is read. Noisy raw data signals are filtered and cleaned up before conversion.

Most FDC interfaces do not directly address tracks; instead they provide "step-in" and "step-out" pulses. Those, and the current sector number virtually rotating under the emulated read/write head, are tracked by the emulator in order to determine which sector is to be accessed.

Because the interface to the floppy drive is very low-level, emulators must maintain the approximate timing of floppy disk operations. This may require the emulator to provide buffering, with some delay in updating the permanent storage.

The emulator saves the data written to the floppy in either local storage (stand-alone emulators), or in a remote storage device or data exchange module (stateless emulators).

Data exchange

The floppy disk emulator can provide other systems access to the data on the emulated floppy in a number of ways:

  • Direct access to some dedicated disk partition (e.g.: a 1.44MB partition on a USB key)
  • Floppy file system translation (e.g.: FAT12 floppy ↔ USB key folder)
  • Floppy disk images (e.g.: raw floppy ↔ .img/.iso USB key file)

Direct access and floppy image implementations can also emulate system / non-standard floppies, whose file system can't be simply translated.

Floppy image implementation can also be coupled with a virtual drive to seamlessly emulate floppy drives on a computer.

Some devices can store multiple floppy images, and provide a mechanism to select which emulated floppy is mounted on the emulated drive.

References

  1. Hardin, Ken (March 18, 2003). "Don't be too quick to dump the floppy". TechRepublic. Archived from the original on June 14, 2018.
  2. "PC World says farewell to floppy". BBC News. January 30, 2007. Archived from the original on February 16, 2018.
  3. "R.I.P. Floppy Disk". BBC News. April 1, 2003. Archived from the original on July 19, 2018.
  4. "3.5-inch floppy still available from Verbatim, [[Imation]] (3M), and Maxell". Archived from the original on 2010-11-30. Retrieved 2011-11-24.
  5. Powers, Jeffrey (April 26, 2010). "Tribute to Floppy Disk as Sony discontinues production". Geek News Central. Archived from the original on May 1, 2010.
  6. "Magnetic Recording Fundamentals". Computer Peripherals (PDF). Singapore: Nanyang Technological University. October 16, 2001. Archived (PDF) from the original on October 2, 2018.
  7. Haardt, Michael; Knaff, Alain; Niemi, David C. (June 11, 2001). "The floppy user guide" (PDF). Archived (PDF) from the original on February 13, 2019.
  8. Kozierok, Charles M. "Floppy Disk Drives". The PC Guide. Archived from the original on March 4, 2001.

See also

Categories: