DOCUMENT:Q75131 17-DEC-2000 [msdos]
TITLE :Standard Floppy Disk Formats Supported by MS-DOS
PRODUCT :Microsoft Disk Operating System
PROD/VER:MS-DOS:1.x,2.x,3.x,4.x,5.x,6.0,6.2,6.21,6.22
OPER/SYS:
KEYWORDS:
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The information in this article applies to:
- Microsoft MS-DOS operating system versions 1.x, 2.11, 3.1, 3.2, 3.21, 3.3, 3.3a, 4.0, 4.01, 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22
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SUMMARY
=======
By using DRIVER.SYS and/or the DRIVPARM command in the CONFIG.SYS file, you can
select a variety of floppy disk formats for use with MS-DOS. The tables below
describe the standard floppy disk formats supported by various versions of
MS-DOS and show the switches used for DRIVER.SYS and FORMAT.EXE.
MORE INFORMATION
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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
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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
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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
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3.5 Inch
Formatted Capacity 720K 1.44 MB 2.88 MB
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# of Heads (Sides) 2 2 2
# of Cyls (Tracks) 80 80 80
# of Sectors/Track 9 18 36
Total # of Sectors 1440 2880 5760
# of Free Sectors 1426 2847 5726
# Sectors/Cluster 2 1 2
Total # 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 112 224 240
Media Descriptor F9 F0 F0
Recorded Density Double High High
MS-DOS Version Began 3.20 3.30 5.00
DRIVER.SYS Switch /F:2 /F:7 /F:9
FORMAT.EXE Switch /F:720 /F:1.44 /F:2.88
Change-Line Support YES YES YES
5.25 Inch
Formatted Capacity 160K 180K 320K 360K 1.2 MB
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# of Heads (Sides) 1 1 2 2 2
# of Cyls (Tracks) 40 40 40 40 80
# of Sectors/Track 8 9 8 9 15
Total # of Sectors 320 360 640 720 2400
# of Free Sectors 313 351 630 708 2371
# Sectors/Cluster 1 1 2 2 1
Total # 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 64 112 112 224
Media Descriptor FE FC FF FD F9
Recorded Density Double Double Double Double High
MS-DOS Version Began 1.00 2.00 1.10 2.00 3.00
DRIVER.SYS Switch /F:0 /F:0 /F:0 /F:0 /F:1
FORMAT.EXE Switch /F:160 /F:180 /F:320 /F:360 /F:1.2
Change-Line Support NO NO NO NO YES
8-Inch
Formatted Capacity 250K 500K 1.2 MB
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# of Heads (Sides) 1 2 2
# of Cyls (Tracks) 77 77 77
# of Sectors/Track 26 26 8
Total # of Sectors 2002 4004 1232
# of Bytes/Sector 128 128 1024
# of Bytes/Cluster 512 512 1024
# Sectors/Cluster 4 4 1
Total # 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 68 192
Media Descriptor FE FD FE
Recorded Density Single Single Double
MS-DOS Version Began 1.00 2.00 2.00
Change-Line Support NO NO NO
Additional query words: 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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Keywords :
Technology : kbMSDOSSearch kbMSDOS321 kbMSDOS400 kbMSDOS1xSearch kbMSDOS320 kbMSDOS330a kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS310 kbMSDOS500 kbMSDOS330 kbMSDOS401 kbMSDOS500a kbMSDOS211
Version : MS-DOS:1.x,2.x,3.x,4.x,5.x,6.0,6.2,6.21,6.22
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