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Document ID: JBAR-3CALQ8

IBM PC330/PC350 - Unknown PCI device showing conflict with secondary IDE controller

Applicable to: World-Wide

Problem :
Customers have been reporting a conflict after they install the Bus-mastering IDE drivers on 65x7 systems running Windows 95. Windows 95 reports this as being a conflict between the Secondary IDE controller and an unknown PCI device. The unknown PCI device is actually the Universal Synchronous Bus (USB).

Problem Analysis :
The conflict is due to the following :
When the systems posts with nothing attached to the secondary IDE controller, BIOS will not reserve IRQ 15 for it. Instead, the USB, being the plug-n-play device that it is, will take IRQ 15. The bus-mastering IDE drivers for Windows 95 are coded to take IRQ 14 for the primary and IRQ 15 for the secondary controller. So Windows 95 reports a conflict because the driver for the secondary IDE controller is trying to use IRQ 15 when the USB is actually using it.

Fix :
There are currently two ways of preventing the USB from using IRQ 15:
1) Put a device on the secondary controller.
2) Make IRQ 15 unavailable in the Configuration Utility.

Search Keywords

Hint Category

Windows 95

Date Created

12-12-96

Last Updated

11-05-98

Revision Date

23-04-99

Brand

IBM PC

Product Family

PC 330, PC 350

Machine Type

6577, 6587

Model

Various

TypeModel

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