Microsoft KB Archive/69577

= FORMAT and 8-Sector Disks in MS-DOS =

Article ID: 69577

Article Last Modified on 5/12/2003

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APPLIES TO


 * Microsoft MS-DOS 4.0 Standard Edition
 * Microsoft MS-DOS 4.01 Standard Edition
 * Microsoft MS-DOS 5.0 Standard Edition
 * Microsoft MS-DOS 5.0a
 * Microsoft MS-DOS 6.0 Standard Edition
 * Microsoft MS-DOS 6.2 Standard Edition
 * Microsoft MS-DOS 6.21 Standard Edition
 * Microsoft MS-DOS 6.22 Standard Edition

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This article was previously published under Q69577



SUMMARY
When you issue the MS-DOS version 4.x FORMAT command with any of the following parameters

/8

/n:8

/f:160

/f:320

FORMAT neither asks for a volume label nor places a BIOS parameter block (BPB) in the boot sector of the resulting disk. In MS-DOS 5.0 and later, if you issue the FORMAT command with any of the above parameters, FORMAT places a BPB in the boot sector, but the disk does not have a volume label.

NOTE: The switches in this list are mutually exclusive. In MS-DOS 6.0, 6.2, and 6.21, you must include a /t parameter with the /n parameter.



MORE INFORMATION
The MS-DOS 4.01 FORMAT utility does not place a BPB in the boot record when a disk is formatted to 8 sectors per track. Disks formatted with 8 sectors per track are considered to be destined for MS-DOS 1.0 compatibility and therefore do not have a defined BPB.

The FORMAT utility also does not ask for a volume label when a disk is formatted to 8 sectors per track. Like the BPB, a volume label is not defined for DOS version 1.0 disks.

The lack of a normal BPB can cause problems for some utility programs that try to read the disk directly. The information stored in a post-1.0 BPB provides information that helps these utilities to locate the FATs and the root directory. These utility programs cannot be used on 8-sector disks.

Because the lack of a BPB can cause problems for some utility programs, the FORMAT utility in MS-DOS versions 5.0 and later places a BPB in the boot record. Appropriate values are included in the BPB. However, the volume label prompt is still skipped, and the final disk has no volume label.

Additional query words: 6.22 4.00 4.01 4.01a 5.00 6.00 6.20

Keywords: KB69577

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