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Q68986: Change-Line Support and XT-Class Computers

Article: Q68986
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:3.x,4.x,5.x,6.0,6.2,6.21,6.22
Operating System(s): 
Keyword(s): 
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 
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SYMPTOMS
========

If you have a 3.5-inch floppy disk drive attached to an XT-class computer
system, when you change disks and use the DIR command, you may see the directory
from the previous disk.

CAUSE
=====

This occurs because MS-DOS assumes that the 3.5-inch drive has change-line error
detection. Most 3.5-inch drives provide change-line support; however, due to XT
architecture, the change-line signal is not passed to MS-DOS.

WORKAROUND
==========

Adding a DRIVPARM command to the CONFIG.SYS file may correct this problem. The
following is sample DRIVPARM command to specify a 720-kilobyte 3.5-inch B
drive:

  DRIVPARM=/D:1 /F:2

Please note that the /C change-line support switch is omitted. When MS-DOS
updates the drive parameters, it may remove the change-line support
requirement.

The floppy disk drive manufacturer may be able to provide a device driver that
corrects the change-line problem. A last option is to install a floppy drive
controller and BIOS that fully support change-line error detection.

Additional query words: 6.22 3.3 3.30 3.3a 3.30a 4.0 4.00 4.01 5.00 5.00a 6.00 6.20

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Keywords          :  
Technology        : 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

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