Change-Line Support and XT-Class Computers (68986)
The information in this article applies to:
• Microsoft MS-DOS operating system 3.1
• Microsoft MS-DOS operating system 3.2
• Microsoft MS-DOS operating system 3.21
• Microsoft MS-DOS operating system 3.3
• Microsoft MS-DOS operating system 3.3a
• Microsoft MS-DOS operating system 4.0
• Microsoft MS-DOS operating system 4.01
• Microsoft MS-DOS operating system 5.0
• Microsoft MS-DOS operating system 5.0a
• Microsoft MS-DOS operating system 6.0
• Microsoft MS-DOS operating system 6.2
• Microsoft MS-DOS operating system 6.21
• Microsoft MS-DOS operating system 6.22
This article was previously published under Q68986
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.
| Modification Type: |
Major |
Last Reviewed: |
5/12/2003 |
| Keywords: |
KB68986 |
|