Throughout the 1970s and 1980s, many different logical disk formats were used, depending on the hardware platform.
More information Platform, Size ...
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 |
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 |
- Format D: Arthur, RISC iX
- Format E: RISC OS
|
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] |
Dual |
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] |
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[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 (1,280) 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.
[25] |
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] |
|
Close
More information Platform, Size ...
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 |
|
|
|
Close
https://www.c64-wiki.com/wiki/Commodore_1571
https://vintagecomputer.ca/files/Commodore/C900/C900%20Floppy%20Specification.pdf