BUG: FDISK Reports Incorrect Disk Capacity for Certain PCMCIA / PCCARD ATA Drives

ID: Q239119

The information in this article applies to:

Microsoft Windows 95
Microsoft Windows 98

SYMPTOMS

FDISK, when run from an MS-DOS box after Windows has been started, reports the wrong disk size for PCCARD-based ATA drives that contain a storage capacity greater than 1023 cylinders. This issue generally applies to disk drives that do not appear in real mode prior to protected-mode Windows (this problem occurs, for example, with drives where the controller has no BIOS extension, so MS-DOS has no way of knowing that they exist).

CAUSE

A bug in the IDE device driver, Esdi_506.pdr, results in FDISK using INT 13 function 8 to obtain disk geometry information. This function truncates the cylinder count to a 10-bit value.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

Additional query words:

Keywords : kbWinOS95bug kbWinOS98bug kbDSupport kbGrpWin9xDDK
Version : WINDOWS:95
Platform : WINDOWS
Issue type : kbbug