8-inch, 5+1⁄4-inch, and 3+1⁄2-inch floppy disks

This is a list of different floppy disk formats.

Physical formats

SizeDensitySidesTrackstpibpiSectoringCoercivityUnformatted capacity per side
2 inch Video Floppy52256>800 kB or 50 fields of analog video
2 inch LT-1Double80245
21⁄2 inchSingle164864 kB
3 inch QuickDisk
3.25 inchSingle1801404,625250 kB
Double9,250500 kB
31⁄2 inchSingle24067.58,650Soft665 Oe250 kB[citation needed]
Double801358,717665 Oe500 kB[citation needed]
High8013517,434720-750 Oe1 MB
Extended8013534,868900 Oe2 MB
Triple240406.536,7006.5 MB
4 inch DemiDiskette1
51⁄4 inchSingle/Double240485,876Soft or hard300 Oe250 kB
Quad77100300 Oe500 kB (Micropolis-compatible)
Quad80965,922300 Oe500 kB
High80969,646Soft600 Oe833 kB
EH10412529,5606.5 MB
51⁄4 inch Apple FileWareDouble28062.5Soft851 kiB
8 inchSingle77483,268-3,408Soft or hard (inner edge)300 Oe1 MB
Double6,8161 MB
HD1549620,560600 Oe9.6 MB
8 inch Memorex FD6501502,400Hard (outer edge)1.5 Mb
651643,1002.5 Mb
8 inch BurroughsDouble21391507,1002

Logical formats

Throughout the 1970s and 1980s, many different logical disk formats were used, depending on the hardware platform.

Common floppy disk formats, logical characteristics by platform
PlatformSizeDensitySidesTracks/ sideSectors/ trackBytes/ sectorSectoringCapacityrpmEncodingNote
Acorn51⁄4 inchSingle14010256Soft100 kB300FM
80200 kB
Double14016256160 kBMFM
80320 kB
2640 kB
31⁄2 inchDouble28016256640 kB300MFMFormat L: MOS (Electron, Master Compact)
51024800 kBFormat D: Arthur, RISC iXFormat E: RISC OS
High101,600 kBFormat F: RISC OS 3 and later. Archimedes models before the A5000 require an upgraded floppy drive.
Agat51⁄4 inchDouble28021256840 kB300MFM
Amiga51⁄4 inchDouble24011512Soft440 kB300MFM
Quad80880 kB
31⁄2 inchDouble880 kB
High191,520 kBGCR
221,760 kB150MFM
Amstrad CPC/PCW3 inchDouble1409512180 kB300MFMSingle head drive, but double-sided floppy discs (total of 360 kB per floppy)
Amstrad PCW8512/95123 inchDouble2809512720 kB300MFM720 kB mode uses both sides - ensure disc inserted correct way up.
Apple II51⁄4 inchDouble13513256Soft113.75 kB300GCR
116140 kB
31⁄2 inchDouble180Variable (8-12)512400 kB394 - 590GCR
2800 kB
High280185121,440 kB300MFM
Apple Lisa51⁄4 inch FileWareDouble246Variable (15-22)512Soft851 kB218 - 320GCR
Apple Lisa 2/Macintosh XL, Macintosh31⁄2 inchDouble180Variable (8-12)512Soft400 kB394 - 590GCR
Macintosh2800 kB
High280185121,440 kB300MFM
Atari 8-bit51⁄4 inchSingle14018128Soft90 kB288FM
Dual26128130 kBMFM
Double18256180 kB
Double218256360 kB300
Atari ST/TT/Falcon31⁄2 inchDouble1809512Soft360 kB300MFM
2720 kB
High181,440 kB
Burroughs MD1228 inchDouble213944256Soft6.26 MB524MFM
Coleco ADAM51⁄4 inchDouble1408512soft160 kB300MFM
Commodore 64 (8-bit)51⁄4 inchDouble135Variable (17-21) ZCAV256Soft170 kB300GCR
2340 kB
Quad177Variable (23-29) ZCAV521 kB
21,042 kB
31⁄2 inchDouble28010512800 kBMFM
Commodore 128 (CP/M)5 1/4Double24026128Soft260K300MFMCommodore 1571
16256320K
9512360K
51,024400K
Commodore 90051⁄4 inchHigh28013-16512Soft1,200kB?GCR
DEC RX018 inchSingle17726128250 kB360FM
DEC RX028 inchDouble17726256500 kB360FM/MFM
DEC RX5051⁄4 inchQuad18010512400 kB300MFM
HP 9114A31⁄2 inchDouble28016256128-710kB600MFMUsed with HP 110 and Portable Series 40 & 70
HP 9895A8 inchDouble277292561.18 MB360MFM
HP 9130K51⁄4 inchDouble23516256286 kB300MFM
IBM 33FD8 inchSingle17726128240.5 kiB360FMDiskette 1
15256277.5 kiB
8512296 kiB
IBM 43FD226128481 kiBDiskette 2
15256555 kiB
IBM 53FDDouble26256962 kiBMFMDiskette 2D
155121.08 MiB
81,0241.16 MiB
IBM PC compatibles8 inchSingle17726128Soft250.25 kB360FM
2500.5 kB
Double181,024616 kBMFM
21,232 kB
51⁄4 inchDouble1408512160 kB300MFM
2320 kB
19180 kB
2360 kB
Quad1808320 kB300
2640 kB
High280151,200 kB360
31⁄2 inchDouble1808512320 kB300MFM
9360 kB
28640 kB
9720 kB
High181,440 kB
211,680 kBDMF
821,720 kB
Extended80362,880 kB
Memorex 6508 inchSingle15083,500 bHard1.4 Mb375FM
Memorex 651Single64321.056 b2.2 Mb
MGT SAM Coupé31⁄2 inchDouble28010512800 kB300MFM
NEC PC-988 inchSingle17726128250.25 kB360FM
Double27781,0241,232 kBMFM
51⁄4 inchDouble2808512640 kB360MFM
9720 kB
High151,200 kB
77 (80)81,0241,232 (1,280) kB
31⁄2 inchDouble2808512640 kB360MFM
9720 kB
High151,200 kB3-mode
77 (80)81,0241,232 (1,280) kB
80185121.44 MB300
Triple240385129,120 kB360NEC PC-88 VA3 2TD drive only
Osborne 151⁄4 inchSingle14010256Soft100 kB300FM
Double51,024200 kBMFM
Sega SF-70003 inchSingle24016256160 kB??Expansion unit for SC-3000 home computer. Capacity is per side.
SHARP X6800051⁄4 inchHigh27781,0241,232 kB360MFM
31⁄2 inch
SHARP CE-1600F, CE-140F21⁄2 inchSingledrive: 1, diskette: 2 (flippable)1685122× 64 kB270GCR (4/5)Internally based on FDU-250 Micro Floppy Disk Drive Unit
Tandy TRS-8051⁄4 inchSingle13510256Soft88 kB300FMModel 1/3/4
51⁄4 inchDouble14018256180 kBMFMModel 1/3/4P
51⁄4 inchDouble24018256360 kBMFMModel 4D
8 inchDouble17726256500 kBMFMModel 2
31⁄2 inchSingle14021,280100 kBFMTandy Portable Disk Drive (aka Brother FB-100, knitking FD-19)
31⁄2 inchSingle18021,280200 kBFMUsed only in Tandy Portable Disk Drive 2
51⁄4 inchDouble13518256157 kBMFMColor Computer
Thomson51⁄4 inchSingle1401612880 kB300FMThomson UD90.070
Double2256320 kBMFMThomson DD90-320
31⁄2 inchDouble18016256320 kB300MFMThomson TO9, Thomson DD09-350
Double2640 kBThomson TO8D, TO9+, Thomson DD90-352
Victor 9000 / ACT Sirius 151⁄4 inchSingle18011-19 (variable)512612 kB252-417 (variable)GCRDisks varied sectors/track and disk speed to keep consistent bit density across tracks
Double25121,196 kB
Vtech Laser210/VZ20051⁄4 inchSingle?4016?Soft78 kB?FMRPM: 75.

See also

  • Zip drive (floppy-like, but incompatible medium using different technology)
  • PocketZip (floppy-like, but incompatible medium using different technology)
  • SuperDisk (floppy-like with drives also compatible with 3.5" floppy disks)
  • Magneto-optical drive (floppy-like, but incompatible medium using different technology)
  • List_of_Ecma_standards (ECMA standards 54, 59, 66, 69, 70, 78, 99, 100, 125 and 147)

Notes

  • (PDF). Product Reference Literature (Fifth ed.). IBM. August 1979.
  • . David Gesswein.
  • . University of Amsterdam. from the original on July 2, 2016.

External links

  • Media related to Floppy disk at Wikimedia Commons
  • at the Museum of Obsolete Media