# List of floppy disk formats

This is a list of different floppy disk formats.

## Physical formats

| Size | Density | Sides | Tracks | tpi | bpi | Sectoring | Coercivity | Unformatted capacity per side |
| 2 inch Video Floppy | | | 52 | 256 | | | | >800 kB or 50 fields of analog video |
| 2 inch LT-1 | double | | 80 | 245 | | | | |
| 21⁄2 inch | Single | | 16 | 48 | | | | 64 kB |
| 3 inch QuickDisk | | | | | | | | |
| 3.25 inch | single | 1 | 80 | 140 | 4,625 | | | 250 kB |
| 3.25 inch | double | 1 | 80 | 140 | 9,250 | | | 500 kB |
| 31⁄2 inch | Single | 2 | 40 | 67.5 | 8,650 | soft | 665 Oe | 250 kB |
| 31⁄2 inch | Double | 2 | 80 | 135 | 8,717 | soft | 665 Oe | 500 kB |
| 31⁄2 inch | High | 2 | 80 | 135 | 17,434 | soft | 720-750 Oe | 1 MB |
| 31⁄2 inch | Extended | 2 | 80 | 135 | 34,868 | soft | 900 Oe | 2 MB |
| 31⁄2 inch | Triple | 2 | 240 | 406.5 | 36,700 | soft | 900 Oe | 6.5 MB |
| 4 inch DemiDiskette | | 1 | | | | | | |
| 51⁄4 inch | Single/Double | 2 | 40 | 48 | 5,876 | soft or hard | 300 Oe | 250 kB |
| 51⁄4 inch | Quad | 2 | 77 | 100 | | soft or hard | 300 Oe | 500 kB (Micropolis-compatible) |
| 51⁄4 inch | Quad | 2 | 80 | 96 | 5,922 | soft or hard | 300 Oe | 500 kB |
| 51⁄4 inch | High | 2 | 80 | 96 | 9,646 | soft | 600 Oe | 833 kB |
| 51⁄4 inch | EH | 2 | 104 | 125 | 29,560 | soft | | 6.5 MB |
| 51⁄4 inch Apple FileWare | Double | 2 | 80 | 62.5 | | soft | | 851 kiB |
| 8 inch | Single | | 77 | 48 | 3,268-3,408 | soft or hard (inner edge) | 300 Oe | 1 MB |
| 8 inch | Double | | 77 | 48 | 6,816 | soft or hard (inner edge) | 300 Oe | 1 MB |
| 8 inch | HD | | 154 | 96 | 20,560 | | 600 Oe | 9.6 MB |
| 8 inch Memorex FD | 650 | 1 | 50 | | 2,400 | hard (outer edge) | | 1.5 Mb |
| 8 inch Memorex FD | 651 | 1 | 64 | | 3,100 | hard (outer edge) | | 2.5 Mb |
| 8 inch Burroughs | Double | 2 | 139 | 150 | 7,100 | | | 2 |

## 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 :
| Platform | Size | Density | Sides | Tracks/ side | Sectors/ track | Bytes/ sector | Sectoring | Capacity | rpm | Encoding | Note |
| Acorn | 51⁄4 inch | Single | 1 | 40 | 10 | 256 | soft | 100 kB | 300 | FM |
| Acorn | 51⁄4 inch | Single | 1 | 80 | 10 | 256 | soft | 200 kB | 300 | FM |
| Acorn | 51⁄4 inch | Double | 1 | 40 | 16 | 256 | soft | 160 kB | 300 | MFM |
| Acorn | 51⁄4 inch | Double | 1 | 80 | 16 | 256 | soft | 320 kB | 300 | MFM |
| Acorn | 51⁄4 inch | Double | 2 | 80 | 16 | 256 | soft | 640 kB | 300 | MFM |
| Acorn | 31⁄2 inch | Double | 2 | 80 | 16 | 256 | soft | 640 kB | 300 | MFM | Format L: MOS (Electron, Master Compact) |
| Acorn | 31⁄2 inch | Double | 2 | 80 | 5 | 1024 | soft | 800 kB | 300 | MFM | Format D: Arthur, RISC iXFormat E: RISC OS |
| Acorn | 31⁄2 inch | High | 2 | 80 | 10 | 1024 | soft | 1,600 kB | 300 | MFM | Format F: RISC OS 3 and later. Archimedes models before the A5000 require an upgraded floppy drive. |
| Agat | 51⁄4 inch | Double | 2 | 80 | 21 | 256 | | 840 kB | 300 | MFM | |
| Amstrad CPC/PCW | 3 inch | Double | 1 | 40 | 9 | 512 | | 180 kB | 300 | MFM | Single head drive, but double-sided floppy discs (total of 360 kB per floppy) |
| Amstrad PCW8512/9512 | 3 inch | Double | 2 | 80 | 9 | 512 | | 720 kB | 300 | MFM | 720 kB mode uses both sides - ensure disc inserted correct way up. |
| Apple II | 51⁄4 inch | Double | 1 | 35 | 13 | 256 | soft | 113.75 kB | 300 | GCR | |
| Apple II | 51⁄4 inch | Double | 1 | 35 | 16 | 256 | soft | 140 kB | 300 | GCR | |
| Apple II | 31⁄2 inch | Double | 1 | 80 | Variable (8-12) | 512 | soft | 400 kB | 394 - 590 | GCR | |
| Apple II | 31⁄2 inch | Double | 2 | 80 | Variable (8-12) | 512 | soft | 800 kB | 394 - 590 | GCR | |
| Apple II | 31⁄2 inch | High | 2 | 80 | 18 | 512 | soft | 1,440 kB | 300 | MFM | |
| Apple Lisa | 51⁄4 inch FileWare | Double | 2 | 46 | Variable (15-22) | 512 | soft | 851 kB | 218 - 320 | GCR | |
| Apple Lisa 2/Macintosh XL, Macintosh | 31⁄2 inch | Double | 1 | 80 | Variable (8-12) | 512 | soft | 400 kB | 394 - 590 | GCR | |
| Apple Macintosh | 31⁄2 inch | Double | 2 | 80 | Variable (8-12) | 512 | soft | 800 kB | 394 - 590 | GCR | |
| Apple Macintosh | 31⁄2 inch | High | 2 | 80 | 18 | 512 | soft | 1,440 kB | 300 | MFM | |
| Atari 8-bit | 51⁄4 inch | Single | 1 | 40 | 18 | 128 | soft | 90 kB | 288 | FM | |
| Atari 8-bit | 51⁄4 inch | Dual | 1 | 40 | 26 | 128 | soft | 130 kB | 288 | MFM | |
| Atari 8-bit | 51⁄4 inch | Double | 1 | 40 | 18 | 256 | soft | 180 kB | 288 | MFM | |
| Atari 8-bit | 51⁄4 inch | Double | 2 | 40 | 18 | 256 | soft | 360 kB | 300 | MFM | |
| Atari ST/TT/Falcon | 31⁄2 inch | Double | 1 | 80 | 9 | 512 | soft | 360 kB | 300 | MFM |
| Atari ST/TT/Falcon | 31⁄2 inch | Double | 2 | 80 | 9 | 512 | soft | 720 kB | 300 | MFM |
| Atari ST/TT/Falcon | 31⁄2 inch | High | 2 | 80 | 18 | 512 | soft | 1,440 kB | 300 | MFM |
| Coleco ADAM | 51⁄4 inch | Double | 1 | 40 | 8 | 512 | soft | 160 kB | 300 | MFM |
| Commodore 64 (8-bit) | 51⁄4 inch | Double | 1 | 35 | Variable (17-21) ZCAV | 256 | soft | 170 kB | 300 | GCR | |
| Commodore 64 (8-bit) | 51⁄4 inch | Double | 2 | 35 | Variable (17-21) ZCAV | 256 | soft | 340 kB | 300 | GCR | |
| Commodore 64 (8-bit) | 51⁄4 inch | Quad | 1 | 77 | Variable (23-29) ZCAV | 256 | soft | 521 kB | 300 | GCR | |
| Commodore 64 (8-bit) | 51⁄4 inch | Quad | 2 | 77 | Variable (23-29) ZCAV | 256 | soft | 1,042 kB | 300 | GCR | |
| Commodore 64 (8-bit) | 31⁄2 inch | Double | 2 | 80 | 10 | 512 | soft | 800 kB | 300 | MFM | |
| Commodore Amiga | 51⁄4 inch | Double | 2 | 40 | 11 | 512 | soft | 440 kB | 300 | MFM | |
| Commodore Amiga | 51⁄4 inch | Quad | 2 | 80 | 11 | 512 | soft | 880 kB | 300 | MFM | |
| Commodore Amiga | 31⁄2 inch | Double | 2 | 80 | 11 | 512 | soft | 880 kB | 300 | MFM | |
| Commodore Amiga | 31⁄2 inch | High | 2 | 80 | 19 | 512 | soft | 1,520 kB | 300 | GCR | |
| Commodore Amiga | 31⁄2 inch | High | 2 | 80 | 22 | 512 | soft | 1,760 kB | 150 | MFM | |
| Commodore 900 | 51⁄4 inch | High | 2 | 80 | 13-16 | 512 | Soft | 1,200kB | ? | GCR | https://vintagecomputer.ca/files/Commodore/C900/C900%20Floppy%20Specification.pdf |
| IBM 33FD | 8 inch | Single | 1 | 77 | 26 | 128 | | 240.5 kiB | 360 | FM | Diskette 1 |
| IBM 33FD | 8 inch | Single | 1 | 77 | 15 | 256 | | 277.5 kiB | 360 | FM | Diskette 1 |
| IBM 33FD | 8 inch | Single | 1 | 77 | 8 | 512 | | 296 kiB | 360 | FM | Diskette 1 |
| IBM 43FD | 8 inch | Single | 2 | 77 | 26 | 128 | | 481 kiB | 360 | FM | Diskette 2 |
| IBM 43FD | 8 inch | Single | 2 | 77 | 15 | 256 | | 555 kiB | 360 | FM | Diskette 2 |
| IBM 53FD | 8 inch | Double | 2 | 77 | 26 | 256 | | 962 kiB | 360 | MFM | Diskette 2D |
| IBM 53FD | 8 inch | Double | 2 | 77 | 15 | 512 | | 1.08 MiB | 360 | MFM | Diskette 2D |
| IBM 53FD | 8 inch | Double | 2 | 77 | 8 | 1,024 | | 1.16 MiB | 360 | MFM | Diskette 2D |
| DEC RX01 | 8 inch | Single | 1 | 77 | 26 | 128 | | 250 kB | 360 | FM | |
| DEC RX02 | 8 inch | Double | 1 | 77 | 26 | 256 | | 500 kB | 360 | FM/MFM | |
| DEC RX50 | 51⁄4 inch | Quad | 1 | 80 | 10 | 512 | | 400 kB | 300 | MFM |
| IBM PC compatibles | 8 inch | Single | 1 | 77 | 26 | 128 | soft | 250.25 kB | 360 | FM | |
| IBM PC compatibles | 8 inch | Single | 2 | 77 | 26 | 128 | soft | 500.5 kB | 360 | FM | |
| IBM PC compatibles | 8 inch | Double | 1 | 77 | 8 | 1,024 | soft | 616 kB | 360 | MFM | |
| IBM PC compatibles | 8 inch | Double | 2 | 77 | 8 | 1,024 | soft | 1,232 kB | 360 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Double | 1 | 40 | 8 | 512 | soft | 160 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Double | 2 | 40 | 8 | 512 | soft | 320 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Double | 1 | 40 | 9 | 512 | soft | 180 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Double | 2 | 40 | 9 | 512 | soft | 360 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Quad | 1 | 80 | 8 | 512 | soft | 320 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | Quad | 2 | 80 | 8 | 512 | soft | 640 kB | 300 | MFM | |
| IBM PC compatibles | 51⁄4 inch | High | 2 | 80 | 15 | 512 | soft | 1,200 kB | 360 | MFM | |
| IBM PC compatibles | 31⁄2 inch | Double | 1 | 80 | 8 | 512 | soft | 320 kB | 300 | MFM |
| IBM PC compatibles | 31⁄2 inch | Double | 1 | 80 | 9 | 512 | soft | 360 kB | 300 | MFM |
| IBM PC compatibles | 31⁄2 inch | Double | 2 | 80 | 8 | 512 | soft | 640 kB | 300 | MFM |
| IBM PC compatibles | 31⁄2 inch | Double | 2 | 80 | 9 | 512 | soft | 720 kB | 300 | MFM |
| IBM PC compatibles | 31⁄2 inch | High | 2 | 80 | 18 | 512 | soft | 1,440 kB | 300 | MFM |
| IBM PC compatibles | 31⁄2 inch | High | 2 | 80 | 21 | 512 | soft | 1,680 kB | 300 | MFM | DMF |
| IBM PC compatibles | 31⁄2 inch | High | 2 | 82 | 21 | 512 | soft | 1,720 kB | 300 | MFM | DMF |
| IBM PC compatibles | 31⁄2 inch | Extended | 2 | 80 | 36 | 512 | soft | 2,880 kB | 300 | MFM |
| MGT SAM Coupé | 31⁄2 inch | Double | 2 | 80 | 10 | 512 | | 800 kB | 300 | MFM | |
| NEC PC98 | 8 inch | Single | 1 | 77 | 26 | 128 | | 250.25 kB | 360 | FM | |
| NEC PC98 | 8 inch | Double | 2 | 77 | 8 | 1,024 | | 1,232 kB | 360 | MFM | |
| NEC PC98 | 51⁄4 inch | Double | 2 | 80 | 8 | 512 | | 640 kB | 360 | MFM |
| NEC PC98 | 51⁄4 inch | Double | 2 | 80 | 9 | 512 | | 720 kB | 360 | MFM | |
| NEC PC98 | 51⁄4 inch | High | 2 | 80 | 15 | 512 | | 1,200 kB | 360 | MFM |
| NEC PC98 | 51⁄4 inch | High | 2 | 77 (80) | 8 | 1,024 | | 1,232 (1,280) kB | 360 | MFM | |
| NEC PC98 | 31⁄2 inch | Double | 2 | 80 | 8 | 512 | | 640 kB | 360 | MFM |
| NEC PC98 | 31⁄2 inch | Double | 2 | 80 | 9 | 512 | | 720 kB | 360 | MFM |
| NEC PC98 | 31⁄2 inch | High | 2 | 80 | 15 | 512 | | 1,200 kB | 360 | MFM | 3-mode |
| NEC PC98 | 31⁄2 inch | High | 2 | 77 (80) | 8 | 1,024 | | 1,232 (1280) kB | 360 | MFM | 3-mode |
| NEC PC98 | 31⁄2 inch | High | 2 | 80 | 18 | 512 | | 1.44 MB | 300 | MFM |
| NEC PC98 | 31⁄2 inch | Triple | 2 | 240 | 38 | 512 | | 9,120 kB | 360 | MFM | NEC PC-88 VA3 2TD drive only |
| Osborne 1 | 51⁄4 inch | Single | 1 | 40 | 10 | 256 | soft | 100 kB | 300 | FM |
| Osborne 1 | 51⁄4 inch | Double | 1 | 40 | 5 | 1,024 | soft | 200 kB | 300 | MFM |
| Sega SF-7000 | 3 inch | Single | 2 | 40 | 16 | 256 | | 160 kB | ? | ? | Expansion unit for SC-3000 home computer. Capacity is per side. |
| SHARP X68000 | 51⁄4 inch | High | 2 | 77 | 8 | 1,024 | | 1,232 kB | 360 | MFM | |
| SHARP X68000 | 31⁄2 inch | High | 2 | 77 | 8 | 1,024 | | 1,232 kB | 360 | MFM | |
| SHARP CE-1600F, CE-140F | 21⁄2 inch | Single | drive: 1, diskette: 2 (flippable) | 16 | 8 | 512 | | 2× 64 kB | 270 | GCR (4/5) | Internally based on FDU-250 Micro Floppy Disk Drive Unit |
| Thomson | 51⁄4 inch | Single | 1 | 40 | 16 | 128 | | 80 kB | 300 | FM | Thomson UD90.070 |
| Thomson | 51⁄4 inch | Double | 2 | 40 | 16 | 256 | | 320 kB | 300 | MFM | Thomson DD90-320 |
| Thomson | 31⁄2 inch | Double | 1 | 80 | 16 | 256 | | 320 kB | 300 | MFM | Thomson TO9, Thomson DD09-350 |
| Thomson | 31⁄2 inch | Double | 2 | 80 | 16 | 256 | | 640 kB | 300 | MFM | Thomson TO8D, TO9+, Thomson DD90-352 |
| Victor 9000 / ACT Sirius 1 | 51⁄4 inch | Single | 1 | 80 | 11-19 (variable) | 512 | | 612 kB | 252-417 (variable) | GCR | Disks varied sectors / track and disk speed to keep consistent bit density across tracks |
| Victor 9000 / ACT Sirius 1 | 51⁄4 inch | Double | 2 | 80 | 11-19 (variable) | 512 | | 1,196 kB | 252-417 (variable) | GCR | Disks varied sectors / track and disk speed to keep consistent bit density across tracks |
| Tandy TRS-80 | 51⁄4 inch | Single | 1 | 35 | 10 | 256 | soft | 88 kB | 300 | FM | Model 1/3/4 |
| Tandy TRS-80 | 51⁄4 inch | Double | 1 | 40 | 18 | 256 | soft | 180 kB | 300 | MFM | Model 1/3/4P |
| Tandy TRS-80 | 51⁄4 inch | Double | 2 | 40 | 18 | 256 | soft | 360 kB | 300 | MFM | Model 4D |
| Tandy TRS-80 | 8 inch | Double | 1 | 77 | 26 | 256 | soft | 500 kB | 300 | MFM | Model 2 |
| Tandy TRS-80 | 31⁄2 inch | Single | 1 | 40 | 2 | 1,280 | soft | 100 kB | 300 | FM | Tandy Portable Disk Drive (aka Brother FB-100, knitking FD-19) |
| Tandy TRS-80 | 31⁄2 inch | Single | 1 | 80 | 2 | 1,280 | soft | 200 kB | 300 | FM | Used only in Tandy Portable Disk Drive 2 |
| Tandy TRS-80 | 51⁄4 inch | Double | 1 | 35 | 18 | 256 | soft | 157 kB | 300 | MFM | Color Computer |
| HP 9114A | 31⁄2 inch | Double | 2 | 80 | 16 | 256 | | 128-710kB | 600 | MFM | Used with HP 110 and Portable Series 40 & 70 |
| HP 9895A | 8 inch | Double | 2 | 77 | 29 | 256 | | 1.18 MB | 360 | MFM | |
| HP 9130K | 51⁄4 inch | Double | 2 | 35 | 16 | 256 | | 286 kB | 300 | MFM | |
| Burroughs MD122 | 8 inch | Double | 2 | 139 | 44 | 256 | soft | 6.26 MB | 524 | MFM | |
| Memorex 650 | 8 inch | single | 1 | 50 | 8 | 3,500 b | hard | 1.4 Mb | 375 | FM | |
| Memorex 651 | 8 inch | single | 1 | 64 | 32 | 1.056 b | hard | 2.2 Mb | 375 | FM | |
| Platform | Size | Density | Side | Track | Sector | Byte | Sectoring | Capacity | RPM | Encoding | Note |
| Commodore 128 (CP/M) | 5 1/4 | Double | 2 | 40 | 26 | 128 | Soft | 260K | 300 | MFM | Commodore 1571 |
| | | | | | 16 | 256 | | 320K | | | |
| | | | | | 9 | 512 | | 360K | | | |
| | | | | | 5 | 1,024 | | 400K | | | |
https://www.c64-wiki.com/wiki/Commodore_1571
https://vintagecomputer.ca/files/Commodore/C900/C900%20Floppy%20Specification.pdf