Floppy Disk Information
These tables are presented as information for the most widely used and popular various stages of floppy disk and diskette history, leading to the current generation of floppy drives in the IBM PC compatible computers. The information here is not intended to show all manufacturers, drives, computers, schemes or devices that were available to the technology sector in general. You may also wish to see our Removable Media Information.
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| Floppy Diskette Data Storage Standards For Compatible PCs |
| | 360KB
DSDD
(1976) | 720 KB
DSDD
(1980) | 1.2 MB
DSHD
(1978) | 1.44 MB
DSHD
(1984) | 2.88 MB
DSED
(1988-IBM) |
| Bit density (max) BPI | 5,876 | 8717 | 9869 | 17434 | 34868 |
| Bytes per Cluster | 1024 | 1024 | 512 | 512 | 1024 |
| Bytes per Sector | 512 | 512 | 512 | 512 | 512 |
| Clusters | 354 | 713 | 2371 | 2847 | 2863 |
| Coating Coercivity (oersteds) | 290 | 650 | 660 | 720 | 1200 |
| Coating Thickness (micrometers) | 2.5 | 1.9 | 1.3 | 0.9 | 0.9 |
| Dimensions | 5¼" | 3½" | 5¼" | 3½" | 3½" |
| Directory Entries | 112 | 112 | 224 | 112 | 240 |
| Directory Sectors | 7 | 7 | 14 | 14 | 15 |
| DOS Version Requirement | v1.0-3.0 | v3.2 | v3.0 | v3.3 | v5.0 |
| FAT Type | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| File Allocation Tables | 2 | 2 | 2 | 2 | 2 |
| Formatted Bytes | 368640 | 737280 | 1228800 | 1474560 | 2949120 |
| Heads | 2 | 2 | 2 | 2 | 2 |
| Interface | MFM | MFM | MFM | MFM | MFM |
| Magnetic Coating Type | Ferrite | Ferrite | Cobalt | Cobalt | Barium |
| Media Density | Low | Low | High | High | Extra-High |
| Media Descriptor Byte | FDH | F9H | F9H | F0H | F0H |
| RPM | 300 | 300 | 300 | 300/360 | 300/360 |
| Sectors | 720 | 1440 | 2400 | 2880 | 5760 |
| Sectors per Cluster | 2 | 2 | 1 | 1 | 2 |
| Sectors per FAT | 2 | 3 | 7 | 9 | 9 |
| Sectors per Track | 9 | 9 | 15 | 18 | 36 |
| Tracks | 40 | 80 | 80 | 80 | 80 |
| Tracks per Inch | 48 | 135 | 96 | 135 | 135 |
Standard 34-Pin
Floppy Drive Connector Cable |
Drive A:
Connector | Drive B:
Connector: | Function | | Drive A:
Connector | Drive B:
Connector: | Function |
| 1 | 1 | Ground | 18 | 18 | Direction (Stepper Motor) |
| 2 | 2 | Unused | 19 | 19 | Ground |
| 3 | 3 | Ground | 20 | 20 | Step Pulse |
| 4 | 4 | Unused | 21 | 21 | Ground |
| 5 | 5 | Ground | 22 | 22 | Write Data |
| 6 | 6 | Unused | 23 | 23 | Ground |
| 7 | 7 | Ground | 24 | 24 | Write Enable |
| 8 | 8 | Index | 25 | 25 | Ground |
| 9 | 9 | Ground | 26 | 26 | Track 0 |
| 16 | 10 | Motor Enable A | 27 | 27 | Ground |
| 15 | 11 | Ground | 28 | 28 | Write Protect |
| 14 | 12 | Drive Select B | 29 | 29 | Ground |
| 13 | 13 | Ground | 30 | 30 | Read Data |
| 12 | 14 | Drive Select A | 31 | 31 | Ground |
| 11 | 15 | Ground | 32 | 32 | Select Head 1 |
| 10 | 16 | Motor Enable B | 33 | 33 | Ground |
| 17 | 17 | Ground | 34 | 34 | Unused |
| Diskette Innovation Timeline |
| Year | Capacity | Size | Sides | Density |
| 1971 | 1.0 KB | 8" | 1 | Single |
| 1973 | 256 KB | 8" | 1 | Single |
| | 160 KB | 8" | 1 | Single |
| | 320 KB | 8" | 1 | Double |
| 1978 | 512 KB | 8" | 1 | Double |
| | 720 KB | 8" | 2 | Double |
| | 1.2 MB | 8" | 2 | Double |
| 1976 | 160 KB | 5¼" | 1 | Double |
| 1976 | 180 KB | 5¼" | 1 | Double |
| 1978 | 320 KB | 5¼" | 2 | Double |
| 1978 | 360 KB | 5¼" | 2 | Double |
| | 720 KB | 5¼" | 2 | Double |
| 1978 | 1.2 MB | 5¼" | 2 | High |
| 1980 | 720 KB | 3½" | 2 | Double |
| 1984 | 1.44 MB | 3½" | 2 | High |
| 1988 | 2.88 MB | 3½" | 2 | Quad |
| 1996 | 120 MB | 3½" | 2 | Ultra-High |
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Version 1.0.1
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