Microsoft KB Archive/294465

= Garbled Video from Camera That Is Connected By Using an IEEE 1394 CardBus Adapter =

Article ID: 294465

Article Last Modified on 1/31/2007

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APPLIES TO


 * Microsoft Windows Millennium Edition

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This article was previously published under Q294465



If this article does not describe your hardware-related issue, please see the following Microsoft Web site to view more articles about hardware:

http://support.microsoft.com/default.aspx/w98?sid=460

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
When you try to view the video output from My Computer or any other digital video program, the video may not be displayed properly. Note that this is more likely to occur when you are using an IEEE 1394 CardBus adapter that is inserted into slot 2 of the CardBus controller while slot 1 is empty.



CAUSE
This issue can be caused by a delay in data transfer when you are using the PCI Clock Run protocol with the TI1450 CardBus controller if the IEEE 1394 adapter is in slot 2 while slot 1 is empty. This leaves slot 1 in a D2 power state. The transfer delay itself is what is garbling the video, as the controller is only receiving partial data.



RESOLUTION
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To work around this issue, use either of the following methods:

Method 1
Use slot 1 for the IEEE 1394 PC Card, or if possible, insert another card into slot 1.

Method 2
Disable power management for the CardBus controller. To do so, use Registry Editor (Regedit.exe) to locate the following registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\PCI

Add a new binary value to this key, and replace the default name &quot;New Value #1&quot; with &quot;AC1B104C&quot; (without the quotation marks). Modify the value of AC1B104C to &quot;00 00 00 20&quot; (without the quotation marks), and then restart your computer.

NOTE: This setting does not affect the CardBus controller's ability to go into Standby or Hibernate.



MORE INFORMATION
When the IEEE 1394 card is inserted in slot 2, the power state of slot 1 is D2 and slot 2 is D0. When picture data transfer is initiated by the IEEE 1394 CardBus adapter in slot 2 and the PCI clock is stopped according to PCI Clock Run protocol, the IEEE 1394 CardBus card asserts a -CLKRUN signal in CardBus to request the restart of the PCI clock. However, the TI 1450 CardBus controller asserts a -CLKRUN signal in the PCI bus 00 with the delay time. This delay of the -CLKRUN assertion in the PCI bus 00 causes the delay of the PCI clock restart, and the transferred data by using the IEEE 1394 CardBus adapter during the delay time is lost. This results in the garbled video.

The following computers are known to be affected by this issue:
 * IBM ThinkPad Models T20, T21, A20m/p, A21m/p

NOTE: This problem will exist in all future Thinkpad models that are equiped with the TI 1450 Cardbus contoller.

To determine if your computer is equipped with a TI 1450 cardbus controller, follow these steps:
 * 1) Click Start, point to Settings, click Control Panel, and then double-click System.
 * 2) Click the Device Manager tab, and then double-click the PCMCIA socket branch to expand it.

The type of PCMCIA controller is listed below this branch.

Additional query words: HWPCMCIA dv HWIEEE

Keywords: kbhardware kbprb KB294465

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