This is a list of different floppy disk formats.
Size | Density | Sides | Tracks | tpi | bpi | Sectoring | Coercivity | Unformatted capacity per side |
---|---|---|---|---|---|---|---|---|
2 inch Video Floppy | 52 | 256 | >800 kB[1] | |||||
2 inch LT-1 | double | 80 | 245 | |||||
21⁄2 inch | Single | 16[2][3] | 48[2] | 64 kB | ||||
3 inch QuickDisk | ||||||||
3.25 inch | single | 1 | 80[4] | 140 | 4,625 | 250 kB | ||
double | 9,250 | 500 kB | ||||||
31⁄2 inch | Single | 2 | 40[5] | 67.5 | 8,650 | soft | 665 Oe | 250 kB[citation needed] |
Double | 80 | 135 | 8,717 | 665 Oe[6] | 500 kB[citation needed] | |||
High | 80 | 135 | 17,434 | 720-750 Oe | 1 MB | |||
Extended | 80 | 135 | 34,868 | 900 Oe | 2 MB | |||
Triple[7] | 240[8] | 406.5[8] | 36,700[8] | 6.5 MB | ||||
4 inch DemiDiskette | 1[9] | |||||||
51⁄4 inch | Single/Double | 2 | 40 | 48 | 5,876 | soft or hard | 300 Oe | 250 kB |
Quad | 77 | 100 | 300 Oe | 500 kB (Micropolis-compatible) | ||||
Quad | 80 | 96 | 5,922 | 300 Oe | 500 kB | |||
High | 80 | 96 | 9,646 | soft | 600 Oe | 833 kB | ||
EH[10] | 104 | 125 | 29,560 | 6.5 MB[11] | ||||
51⁄4 inch
Apple FileWare |
Double | 2 | 80 | 62.5 | soft | 851 kiB[12] | ||
8 inch | Single | 77 | 48 | 3,268-3,408 | soft or hard (inner edge) | 300 Oe | 1 MB | |
Double | 6,816 | 1 MB | ||||||
HD[13] | 154 | 96 | 20,560 | 600 Oe | 9.6 MB[14] | |||
8 inch Memorex FD | 650 | 1[15] | 50[15] | 2,400 | hard (outer edge) | 1.5 Mb[15] | ||
651 | 64[16] | 3,100 | 2.5 Mb[16][17] | |||||
8 inch Burroughs | Double | 2 | 139 | 150 | 7,100 | 2[18] |
Throughout the 1970s and 1980s, many different logical disk formats were used, depending on the hardware 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 | |
80 | 200 kB | ||||||||||
Double | 1 | 40 | 16 | 256 | 160 kB | MFM | |||||
80 | 320 kB | ||||||||||
2 | 640 kB | ||||||||||
31⁄2 inch | Double | 2 | 80 | 16 | 256 | 640 kB | 300 | MFM | Format L: MOS (Electron, Master Compact) | ||
5 | 1024 | 800 kB |
| ||||||||
High | 10 | 1,600 kB | 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 | [NB 1] | |
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 | [NB 2] |
1 | 16 | 140 kB | |||||||||
31⁄2 inch | Double | 1 | 80 | Variable (8-12) | 512 | 400 kB | 394 - 590 | GCR | [NB 3] | ||
2 | 800 kB | ||||||||||
High | 2 | 80 | 18 | 512 | 1,440 kB | 300 | MFM | [NB 4] | |||
Apple Lisa | 51⁄4 inch FileWare | Double | 2 | 46 | Variable (15-22) | 512 | soft | 851 kB | 218 - 320[19] | 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 | 2 | 800 kB | |||||||||
High | 2 | 80 | 18 | 512 | 1,440 kB | 300 | MFM | ||||
Atari 8-bit | 51⁄4 inch | Single | 1 | 40 | 18 | 128 | soft | 90 kB | 288 | FM | [NB 5] |
Double | 26 | 128 | 130 kB | MFM | |||||||
Double | 18 | 256 | 180 kB | ||||||||
Double | 2 | 18 | 256 | 360 kB | 300 | ||||||
Atari ST/TT/Falcon | 31⁄2 inch | Double | 1 | 80 | 9 | 512 | soft | 360 kB | 300 | MFM | |
2 | 720 kB | ||||||||||
High | 18 | 1,440 kB | |||||||||
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 | [NB 6] |
2 | 340 kB | ||||||||||
Quad | 1 | 77 | Variable (23-29) ZCAV | 521 kB | |||||||
2 | 1,042 kB | ||||||||||
31⁄2 inch | Double | 2 | 80 | 10 | 512 | 800 kB | MFM | ||||
Commodore Amiga | 51⁄4 inch | Double | 2 | 40 | 11 | 512 | soft | 440 kB[NB 7] | 300 | MFM | [NB 8] |
Quad | 80 | 880 kB[NB 9] | |||||||||
31⁄2 inch | Double | 880 kB | |||||||||
High | 19 | 1,520 kB | GCR | [NB 10] | |||||||
22 | 1,760 kB | 150 | MFM | [NB 8] | |||||||
IBM 33FD | 8 inch | Single | 1 | 77 | 26 | 128 | 240.5 kiB | 360 | FM | Diskette 1[20] | |
15 | 256 | 277.5 kiB | |||||||||
8 | 512 | 296 kiB | |||||||||
IBM 43FD | 2 | 26 | 128 | 481 kiB | Diskette 2[20] | ||||||
15 | 256 | 555 kiB | |||||||||
IBM 53FD | Double | 26 | 256 | 962 kiB | MFM | Diskette 2D[20] | |||||
15 | 512 | 1.08 MiB | |||||||||
8 | 1,024 | 1.16 MiB | |||||||||
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[21] | 8 inch | Single | 1 | 77 | 26 | 128 | soft | 250.25 kB[NB 11][21][22][23] | 360 | FM | [NB 12] |
2 | 500.5 kB[NB 11][21][22][23] | ||||||||||
Double | 1 | 8 | 1,024 | 616 kB[NB 11][22][23] | MFM | ||||||
2 | 1,232 kB[NB 11][21][22][23] | ||||||||||
51⁄4 inch | Double | 1 | 40 | 8 | 512 | 160 kB[NB 11] | 300 | MFM | |||
2 | 320 kB[NB 11] | ||||||||||
1 | 9 | 180 kB[NB 11] | |||||||||
2 | 360 kB[NB 11] | ||||||||||
Quad[NB 13] | 1 | 80 | 8 | 320 kB[NB 11] | 300 | ||||||
2 | 640 kB[NB 11] | ||||||||||
High | 2 | 80 | 15 | 1,200 kB[NB 11] | 360 | ||||||
31⁄2 inch | Double | 1 | 80 | 8 | 512 | 320 kB[NB 11] | 300 | MFM | |||
9 | 360 kB[NB 11] | ||||||||||
2 | 8 | 640 kB[NB 11] | |||||||||
9 | 720 kB[NB 11] | ||||||||||
High | 18 | 1,440 kB[NB 11] | |||||||||
21 | 1,680 kB[NB 11] | DMF[NB 14] | |||||||||
82 | 1,720 kB[NB 11] | ||||||||||
Extended | 80 | 36 | 2,880 kB[NB 11] | ||||||||
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[NB 11] | 360 | FM | ||
Double | 2 | 77 | 8 | 1,024 | 1,232 kB[NB 11] | MFM | |||||
51⁄4 inch | Double | 2 | 80 | 8 | 512 | 640 kB[NB 11] | 360 | MFM | |||
9 | 720 kB[NB 11] | ||||||||||
High | 15 | 1,200 kB[NB 11] | |||||||||
77 (80)[NB 15] | 8 | 1,024 | 1,232 (1,280) kB[NB 11][NB 15] | [NB 15] | |||||||
31⁄2 inch | Double | 2 | 80 | 8 | 512 | 640 kB[NB 11] | 360 | MFM | |||
9 | 720 kB[NB 11] | ||||||||||
High | 15 | 1,200 kB[NB 11] | 3-mode[NB 16][NB 15] | ||||||||
77 (80)[NB 15] | 8 | 1,024 | 1,232 (1280) kB[NB 11][NB 15] | ||||||||
80 | 18 | 512 | 1.44 MB[NB 11] | 300 | |||||||
Triple | 240 | 38 | 512 | 9,120 kB | 360 | NEC PC-88 VA3 2TD drive only[8][7] | |||||
Osborne 1[24] | 51⁄4 inch | Single | 1 | 40 | 10 | 256 | soft | 100 kB | 300 | FM | |
Double | 5 | 1,024 | 200 kB | 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[NB 11] | 360 | MFM | ||
31⁄2 inch | |||||||||||
SHARP CE-1600F, CE-140F | 21⁄2 inch[2][3] | 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[2] | |
Thomson | 51⁄4 inch | Single | 1 | 40 | 16 | 128 | 80 kB | 300 | FM | Thomson UD90.070 | |
Double | 2 | 256 | 320 kB | MFM | Thomson DD90-320[NB 17] | ||||||
31⁄2 inch | Double | 1 | 80 | 16 | 256 | 320 kB | 300 | MFM | Thomson TO9, Thomson DD09-350 | ||
Double | 2 | 640 kB | Thomson TO8D, TO9+, Thomson DD90-352[NB 18] | ||||||||
Victor 9000 / ACT Sirius 1[26] | 51⁄4 inch | Single | 1 | 80 | 11-19 (variable) | 512 | 612 kB[27] | 252-417 (variable) | GCR | Disks varied sectors / track and disk speed to keep consistent bit density across tracks[26] | |
Double | 2 | 512 | 1,196 kB[27] | ||||||||
Tandy TRS-80 | 51⁄4 inch | Single | 1 | 35 | 10 | 256 | soft | 88 kB | 300 | FM | Model 1/3/4 |
51⁄4 inch | Double | 1 | 40 | 18 | 256 | 180 kB | MFM | Model 1/3/4P | |||
51⁄4 inch | Double | 2 | 40 | 18 | 256 | 360 kB | MFM | Model 4D | |||
8 inch | Double | 1 | 77 | 26 | 256 | 500 kB | MFM | Model 2 | |||
31⁄2 inch | Single | 1 | 40 | 2 | 1,280 | 100 kB[28] | FM | Tandy Portable Disk Drive (aka Brother FB-100, knitking FD-19) | |||
31⁄2 inch | Single | 1 | 80 | 2 | 1,280 | 200 kB[29] | FM | Used only in Tandy Portable Disk Drive 2 | |||
51⁄4 inch | Double | 1 | 35 | 18 | 256 | 157 kB[30] | MFM | Color Computer | |||
HP 9114A | 31⁄2 inch | Double | 2 | 80 | 16 | 256 | 128-710kB[31] | 600 | MFM | Used with HP 110 and Portable Series 40 & 70 | |
HP 9895A | 8 inch | Double | 2 | 77 | 29 | 256 | 1.18 MB[32] | 360 | MFM | ||
HP 9130K | 51⁄4 inch | Double | 2 | 35 | 16 | 256 | 286 kB[33] | 300 | MFM | ||
Burroughs MD122 | 8 inch | Double | 2 | 139 | 44 | 256 | soft | 6.26 MB[18] | 524 | MFM | |
Memorex 650 | 8 inch | single | 1 | 50 | 8 | 3,500 b | hard | 1.4 Mb[15] | 375 | FM | |
Memorex 651 | single | 64 | 32 | 1.056 b | 2.2 Mb[17] |
Platform | Size | Density | Side | Track | Sector | Byte | Sectoring | Capactiy | 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