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Standard Floppy Disk Formats Supported by MS-DOS

This article was previously published under Q75131
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SUMMARY
By using DRIVER.SYS and/or the DRIVPARM command in the CONFIG.SYS file, youcan select a variety of floppy disk formats for use with MS-DOS. The tablesbelow describe the standard floppy disk formats supported by variousversions of MS-DOS and show the switches used for DRIVER.SYS andFORMAT.EXE.
MORE INFORMATION
The tables below include information on the following:
   Number of heads (sides)   Number of cylinders (tracks)   Number of sectors per track   Total number of sectors   Number of free sectors   Number of sectors per cluster   Total number of clusters   Number of sectors per FAT (file allocation table)   Number of FAT copies   Number of root directory sectors   Number of reserved sectors   Number of hidden sectors   Number of bytes per sector   Number of bytes per cluster   Number of root directory entries   The media descriptor byte for each format   What recording density was used to create the floppy disk   Under what MS-DOS version this format was first supported   What parameter to use with DRIVER.SYS for this format   What parameter to use with FORMAT.EXE for this format   Whether or not the changed-diskette line is supported				

NOTES

  1. The switches shown for DRIVER.SYS can also be used for DRIVPARM. Example: The line "Device=C:\DOS\DRIVER.SYS /D:1 /F:9 /C" in the CONFIG.SYS file specifies that floppy disk drive B is a 2.88-megabyte (MB) 3.5-inch floppy disk drive that supports the changed-diskette line.

    Example: The line "DRIVPARM=/D:1 /F:9 /C" in the CONFIG.SYS file specifies that the floppy disk drive B is a 2.88-MB 3.5-inch floppy disk drive that supports the Change line.

    Example: The command "FORMAT B: /F:720" formats a double-sided double-density 720K floppy disk in a 1.44-MB or 2.88-MB 3.5-inch floppy disk drive that is installed in the computer as floppy disk drive B.
  2. The following charts refer to "Clusters," whereas MS-DOS 5.0 and later refer to "Allocation Units." These two terms are equivalent and describe the same data structure.
  3. Multiple formats with the same DRIVER.SYS switch is NOT an error.
  4. Multiple formats with the same media descriptor byte does NOT indicate an error.
  5. Valid media descriptor bytes for MS-DOS are listed below:
          Byte   Capacity   Media Size and Type      ---------------------------------------------------      F0     2.88 MB    3.5-inch, 2-sided, 36-sector      F0     1.44 MB    3.5-inch, 2-sided, 18-sector      F9     720K       3.5-inch, 2-sided, 9-sector      F9     1.2 MB     5.25-inch, 2-sided, 15-sector      FD     360K       5.25-inch, 2-sided, 9-sector      FF     320K       5.25-inch, 2-sided, 8-sector      FC     180K       5.25-inch, 1-sided, 9-sector      FE     160K       5.25-inch, 1-sided, 8-sector      FE     250K       8-inch, 1-sided, single-density      FD     500K       8-inch, 2-sided, single-density      FE     1.2 MB     8-inch, 2-sided, double-density      F8     -----      Fixed disk						
  6. Both track and cylinder numbers are zero-based. For example, 360K 5.25-inch floppy disks have 40 tracks numbered 0 through 39. Similarly, head numbers and side numbers are also zero-based. For example, 360K 5.25-inch floppy disks have sides 0 and 1 (corresponding to heads 0 and 1). However sectors are one-based. For example, 360K 5.25-inch floppy disks have sectors numbered 1 through 9.

Standard Floppy Disk Formats Supported by MS-DOS

3.5 Inch

Formatted Capacity 720K 1.44 MB 2.88 MB

# of Heads (Sides)         2         2         2# of Cyls (Tracks)        80        80        80# of Sectors/Track         9        18        36Total # of Sectors      1440      2880      5760# of Free Sectors       1426      2847      5726# Sectors/Cluster          2         1         2Total # of Clusters      713      2847      2863# Sectors/FAT              3         9         9# of FAT Copies            2         2         2# of Root Dir Sectors      7        14        15# Reserved Sectors         1         1         1# of Hidden Sectors        0         0         0# of Bytes/Sector        512       512       512# of Bytes/Cluster      1024       512      1024# Root Dir Entries       112       224       240Media Descriptor          F9        F0        F0Recorded Density      Double      High      HighMS-DOS Version Began    3.20      3.30      5.00DRIVER.SYS Switch       /F:2      /F:7      /F:9FORMAT.EXE Switch     /F:720   /F:1.44   /F:2.88Change-Line Support      YES       YES       YES5.25 Inch				

Formatted Capacity 160K 180K 320K 360K 1.2 MB

# of Heads (Sides)         1        1        2        2         2# of Cyls (Tracks)        40       40       40       40        80# of Sectors/Track         8        9        8        9        15Total # of Sectors       320      360      640      720      2400# of Free Sectors        313      351      630      708      2371# Sectors/Cluster          1        1        2        2         1Total # of Clusters      313      351      315      354      2371# of Sectors/FAT           1        2        1        2         7# of FAT Copies            2        2        2        2         2# of Root Dir Sectors      4        4        7        7        14# Reserved Sectors         1        1        1        1         1# of Hidden Sectors        0        0        0        0         0# of Bytes/Sector        512      512      512      512       512# of Bytes/Cluster       512      512     1024     1024       512# Root Dir Entries        64       64      112      112       224Media Descriptor          FE       FC       FF       FD        F9Recorded Density      Double   Double   Double   Double      HighMS-DOS Version Began    1.00     2.00     1.10     2.00      3.00DRIVER.SYS Switch       /F:0     /F:0     /F:0     /F:0      /F:1FORMAT.EXE Switch     /F:160   /F:180   /F:320   /F:360    /F:1.2Change-Line Support       NO       NO       NO       NO       YES8-Inch				

Formatted Capacity 250K 500K 1.2 MB

# of Heads (Sides)         1        2        2# of Cyls (Tracks)        77       77       77# of Sectors/Track        26       26        8Total # of Sectors      2002     4004     1232# of Bytes/Sector        128      128     1024# of Bytes/Cluster       512      512     1024# Sectors/Cluster          4        4        1Total # of Clusters      497      997     1227# Reserved Sectors         1        4        1# of Hidden Sectors        3        0        0# Sectors/FAT              6        6        2# of FAT Copies            2        2        2# Root Dir Entries        68       68      192Media Descriptor          FE       FD       FERecorded Density      Single   Single   DoubleMS-DOS Version Began    1.00     2.00     2.00Change-Line Support       NO       NO       NO				
6.22 1.00 1.10 2.00 3.00 3.20 3.21 3.30 3.30a 4.00 4.01 4.01a 5.00 5.00a 6.00 6.20
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Article ID: 75131 - Last Review: 05/12/2003 20:40:35 - Revision: 2.0

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