Technical Advisory
Intel Motherboards using the 82371SB PIIX3 Component
April 26, 1996
Description
The retail version of Microsoft Windows* 95 may not
recognize the Intel 82371SB PIIX3 IDE controller
on Intel motherboards, causing the BIOS to disable
the secondary IDE channel. This can result in IDE
devices (such as CD-ROM drives) not being detected
or disappearing after the system is rebooted.
This affects only the retail version of Windows 95.
The OEM version has an updated MSHDC.INF file
included in the OPK release and is not affected by
this issue.
Root Cause
The 82371SB is not included in the list of IDE
controllers in the MSHDC.INF file shipped with
the retail version of Windows 95. During installation,
Windows 95 sees the IDE functionality but can't
identify the exact controller type. It enables
the primary IDE channel of the 82371SB, but assumes
that the secondary IDE channel belongs to a non-plug
and play ISA IDE controller. Windows 95 then adds
this information to the plug and play configuration
area. When the system is rebooted, the motherboard
BIOS interprets this information as indicating an
ISA IDE expansion card has been installed, and
disables the onboard secondary IDE channel -
rendering any devices on this channel inaccessible.
The most common symptom is that the CD-ROM drive
will not be recognized by Windows 95 after rebooting
the system.
Affected Products
This issue affects all Intel motherboard products
with the 82371SB component.
Workaround / Action
To determine how the system has been configured,
look in the Windows 95 Device Manager (click START,
SETTINGS, CONTROL PANEL, double click on the SYSTEM
icon, then click on the Device Manager tab). Double
click on Hard Disk Controllers. If you see the
following drivers listed, the system has NOT been
configured correctly:
-Hard Disk Controllers
-Primary IDE Controller (single FIFO)
-Standard Dual PCI IDE Controller
-Standard IDE/ESDI Hard Disk Controller
An Install Wizard has been developed that adds an
entry for the 82371SB IDE controller into the
MSHDC.INF file. This utility (file name IDEINFUP.EXE,
self-extracting zip file format) is available from
the Intel FTP site at ftp://ftp.intel.com/pub/patch,
or from the Intel BBS (503-264-7999). Download this
utility and follow the instructions to update the
hard drive configuration file.
OEM Products and Services Division
Intel Corporation
*Other trademarks and brands are the property of
their respective owners.