Q73033: Workarounds for the MS-DOS 1024-Cylinder Limit

Article: Q73033
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22; WINDOWS:95
Operating System(s): 
Keyword(s): msdos
Last Modified: 17-DEC-2000

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The information in this article applies to:

- Microsoft MS-DOS operating system versions 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 
- Microsoft Windows 95 
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SUMMARY
=======

Because MS-DOS uses the ROM BIOS to access the hard drive, MS-DOS is limited to
the standard AT ROM BIOS interface's maximum of 1024 cylinders. It is possible
to have a CMOS Setup allow viewing the full number of cylinders but still have
the BIOS limited to using only 1024 cylinders.

MORE INFORMATION
================

There are four methods to work around this problem:

- Purchase a hard disk controller card that translates the drive's parameters
  into values acceptable to the ROM BIOS and to MS-DOS. This allows you to
  partition and format the entire drive with MS-DOS. For information about
  purchasing such a controller, contact your hard drive or hard drive
  controller manufacturer.

- Use a software package to translate the drive's parameters into values
  acceptable to MS-DOS. Examples of this type translation software include
  SpeedStor from Storage Dimensions and Disk Manager from OnTrack Software.

  Warning: A side effect of this solution can cause data corruption with most
  disk caches, including Microsoft's SMARTDRV.SYS. This is why later versions
  of SMARTDRV.SYS, which were shipped with Windows version 3.00a and MS-DOS
  version 5.0, refuse to load if the partitions created by these utilities
  exist. MS-DOS 5.0 allows an override of this safety feature; however, it
  should not be used if the disk has more than 1024 cylinders and translation
  software is installed.

  See section 7.5 of the MS-DOS 5 Upgrade README.TXT for more information.

- Use only the first 1024 cylinders of the disk.

- Purchase a hard drive with 1024 cylinders or less.

The products included above, Disk Manager and SpeedStor, including their software
drivers in the Microsoft MS-DOS 5 Upgrade, are manufactured by vendors
independent of Microsoft; we make no warranty, implied or otherwise, regarding
these products' performance or reliability. This information is included only
for the user's convenience.

MS-DOS 5.x compatible versions of the drivers used by these products are included
in the Microsoft MS-DOS 5 Upgrade.

Additional query words: 6.22 3.20 3.21 3.30 3.30a 4.00 4.01 4.01a 5.00 6.00 6.20 6.21

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Keywords          : msdos 
Technology        : kbWin95search kbZNotKeyword3 kbMSDOSSearch kbMSDOS321 kbMSDOS400 kbMSDOS320 kbMSDOS330a kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS310 kbMSDOS500 kbMSDOS330 kbMSDOS401 kbMSDOS500a
Version           : MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22; WINDOWS:95

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