Erratic Floppy Drive Behavior on Mitsubishi 286 (76185)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q76185


On a Mitsubishi 286 machine, after upgrading to Microsoft MS-DOS version 5.0, a "Sector Not Found Error" message may be displayed when trying to write or execute a file on a floppy disk. Also, it may seem that MS-DOS is incorrectly perceiving the drive density. The CMOS settings may read 1.2 MB. However, if a disk utility is run, it may show the density as 360K.


The above problem is due to the particular version of ROM BIOS on some Mitsubishi 286 motherboards. Version 1.52f does not directly support 1.2 MB disk drives; it initializes the disk base table to 9 sectors per track when it should be using 15 sectors per track for 1.2 MB disks.

Using DRIVPARM will not alleviate this problem because BIOS version 1.52f will not support the calls DRIVPARM uses to change the drive type.

A BIOS upgrade will solve the problem. To obtain an upgrade, call Mitsubishi technical support at (800) 344-6352.

The product included here is manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.

Modification Type: Major Last Reviewed: 11/23/1999
Keywords: KB76185