dma checkbox won't stay checked

[Nir Aloni]

I am developing a new atapi device (cd). As part of my testings, I checked the DMA capability of my device. As the device was configured as master, I checked the dma checkbox in windows and rebooted. everything worked properely and the box remained checked.
As I configured my device as slave, and did the same process, after rebooting, the checkbox didn't remain checked.
some facts :

My device supports dma for sure
other cd devices worked properly either as slave or master on the sam host.

I think that the solution to my problem relies in : "what happens in software and hardware as I check the dma checkbox in windows" ?

please, help

[BigBlue66]

Hi and Welcome!

I think your best bet is to do a search on Direct Memory Access. You will see the PCGuide as one of the first hits.

I for one cannot summarize all there is to know about DMA in a couple of paragraphs.

Good luck.

Big Blue 66


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Woe is me.

[Nir Aloni]

hi,
belive it or not, I read all the sites about DMA and no one can answer my question.

Originally posted by BigBlue66:
Hi and Welcome!

I think your best bet is to do a search on Direct Memory Access. You will see the PCGuide as one of the first hits.

I for one cannot summarize all there is to know about DMA in a couple of paragraphs.

Good luck.

Big Blue 66

[BigBlue66]

Hi Nir,

Sorry to hear that. The only thing I can think of is that the DMA function works on the first peripheral (Master) that is hooked up to the IDE channel, and not the second one in line (Slave).

Sorry, that is probably not the answer you were seeking, but it's my best shot. At least it makes sense to a certain point, but as for why it might do that, I haven't a clue.

Hopefully, a few others will have an idea or two. Hang tight.

Cheers,

Big Blue 66


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Woe is me.

[bassvax]

Here are a couple of links discussing something similar...maybe they will help..If not, use Google (http://www.google.com) to find more info...there were several hits using this phrase "dma enabling on slave devices" http://www.PCGuide.com/ubb/smile.gif

MSKB Article 1 (http://support.microsoft.com/support/kb/articles/Q158/8/73.asp)

MSKB Article 2 (http://support.microsoft.com/support/kb/articles/Q182/5/32.ASP)

Solaris Article (http://groups.yahoo.com/group/solarisonintel/message/15915)

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