DMA causes problems



Hi there
When I enable DMA on my hard drives and cdrom and then try and run zip files or setup files I often get an crc error or an I/O error. Occasionally files that were working are now apparently corrupted. Often, but not always, the errors seem to occur when the zip program is unzipping a large file (such as a .wad file). The problem occurs whether I try to install from cd's or copy the files from the cd to the hard drive and try and install or unzip from there.
When I disable DMA things work OK.
I have a western digital and a seagate Hard drive, and a Sony cdrom and Sony burner. The hard drives are on the primary IDE and the two cd's are on the secondary IDE.

I have an Aopen motherbord with a VIA Apollo chip, Celeron 466, 256 meg RAM and am running Windows 98. I have all the latest drivers from Microsoft for Windows and all the latest drivers from Aopen for the motherboard.

Any suggestions?

Thanks in advance



I'm assuming the problem occurs when DMA is enabled on the channel that has the CD-ROM drives, but if you disable that one, it works, right? Regardless of how the other channel is set? Check that first off.

Also, I'd try re-seating your IDE cables, or better yet, try another cable. They can come loose pretty easily inside the case, and I've seen some IDE cables take enough abuse that the connector comes loose and you get an intermittent connection, which causes problems.

Dave Farquhar
Author, <i>Optimizing Windows for Games, Graphics and Multimedia</i> (O'Reilly)
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