Can't Enable DMA

[mrhair]

Hello, I am having trouble enabling DMA for my hard drive, DVD and CDRW drives. Previously, DMA was enabled for all the drives, but I recently did a clean install of Windows 98 and now I can't get the DMA boxes for the drives to remain checked. Any help would be appreciated. Thanks.

 

[HaVoC]

First, check to see if DMA mode is enabled in the BIOS for both IDE channels. PIO Mode 4 is a bad thing if that's what you see.

My other suggestion is to check your cabling. Your HD should ideally be b]alone[/b] on the primary IDE channel as the master. The CD-RW and CD/DVD drive should be on the secondary IDE.

Some CD-RW and CD drives don't support UDMA, so this will cause the HD to fall out into PIO modes if they share the same IDE channel. Hope this helps.

 

[mrhair]

Hey,
My boot drive is on a Promise ATA/66 card, so that one has UDMA mode 4 automatically. Also, I have a Maxtor hard drive on the primary IDE and the DVD and CDRW on the secondary. They've always been set up like this though I've never had this problem before. In the BIOS, my Asus automatically detects the drives. It gives the dvd and cdrw PIO mode 4 but disables UDMA and gives the hard drive DMA mode 2. Before though, I could still enable DMA in Windows, but not now after reinstalling. They are both newer drives and they do support DMA.

 

[downhiller80]

I'm pretty sure the promise cards ALWAYS have DMA enabled, whether it shows up or not. I know 98 has some issues with those DMA boxes. Maybe you have a service pack that corrected it before you re-installed?

Just because it isn't ticked doesn't mean it's not active!

Seb

 

[peemo]

Could be a function of using UDMA 4. I can't get the DMA box to stay checked on my CDROM in WIN98 and I'm using a Soyo 6BA+IV with Highpoint ATA66 controllers.

 

[403Forbidden]

id bios use pio mode 2 and and then dma will work

 

[mrhair]

Thanks for all the tips!
Just to make something clear, I only had one hard drive on the Promise Ultra66 card. The other hard drive and optical drives were using the onboard ide/33 channels. The drive on the Promise was always at 66 and there is no DMA checkbox for that drive, which is normal.
peemo: That's exactly what's happening. So I thought it might be caused by the Promise card itself or its drivers, so I took out the card and presto, DMA boxes stay checked now!
403Forbidden: Thanks for the tip, I tried changing the information in the BIOS from Auto to Manual so I could change the parameters, but when I did Windows wouldn't boot. So for now I am going to live with ata/33 until I get a mobo with onboard ata/66.
Thanks for the help everyone. By the way, do any of you know why playing a music cd would cause mouse lag in DOS games? Specifically: C&C: Red Alert and Duke Nukem 3D.

Thanks,
mrhair