Technical Advisory
Intel Motherboards using the 82371SB PIIX3 Component

April 24, 1996


Description

The retail version of Microsoft Windows* 95 may not recognize identify 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 cant 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.  Currently, these products are the Advanced/ML, Advanced/RH, and
VS440FX.


Workaround / Action

To determine if the system has not been configured correctly, 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 82371SBIDE.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.


*Other trademarks and brands are the property of their respective owners.
