High Bandwidth May Not Be Available with 1394 Open Host Controller (252958)



The information in this article applies to:

  • Microsoft Windows 98 Second Edition

This article was previously published under Q252958

SYMPTOMS

Institute of Electrical and Electronics Engineering (IEEE) 1394 devices that require more than 200 megabits per second (Mbps) bandwidth may be unable to allocate this bandwidth when the device is connected to a 1394 host controller on a Windows 98 Second Edition-based computer.

CAUSE

This problem can occur if the 1394 OpenHCI host controller contains 4 or more ports. The 1394bus.sys driver for Windows 98 Second Edition is not able to parse the Self-ID packets properly if the 1394 Host Controller sends multiple Self-ID packets to the computer (which occurs if the controller contains 4 or more ports). Under this condition, the 1394 bus driver sets the controller speed capability to 200 Mbps instead of 400 Mbps. Any 1394 physical-layer unit (PHY) which contains more than 3 ports must send multiple self-ID packets, because each 1394 self-ID packet can describe a maximum of 3 ports.

RESOLUTION

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next service pack that contains this fix.

To resolve this problem immediately, download the fix by clicking the download link later in this article or contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The following files are available for download from the Microsoft Download Center:
The English-language version of this fix contains the following files:
   Date     Time     Version     Size     File name   
   ---------------------------------------------------
   2/8/00   3:47pm   4.10.2225   38,016   1394bus.sys 
   2/8/00   3:43pm   4.10.2225   36,256   Ohci1394.sys
				
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.

STATUS

Microsoft has confirmed that this is a problem in Windows 98 Second Edition.

MORE INFORMATION

The following OpenHCI 1394 controllers/chipsets are known to be affected by this problem:
  • VIA Technologies VT6304 PHY (physical layer) chipset


For additional information about Windows 98 and Windows 98 Second Edition hotfixes, click the article number below to view the article in the Microsoft Knowledge Base:

206071 General Information About Windows 98 and Windows 98 Second Edition Hotfixes

For additional information about this problem as it occurs on Windows 2000, click the article number below to view the article in the Microsoft Knowledge Base:

253152 Under Windows 2000, NetMeeting Runs Without Video With VIA 1394

For additional information about another issue resolved by this update, click the article number below to view the article in the Microsoft Knowledge Base:

252183 1394 Host Controller Driver Does Not Retry Busy Devices Properly


Modification Type:MinorLast Reviewed:9/26/2005
Keywords:kbHotfixServer kbQFE kbdownload kbenv kbfix kbgraphxlinkcritical kbHardware kbprb kbQFE KB252958