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Date: Sat, 4 Jun 2005 16:12:09 +0200
From: Joerg Sonnenberger <joerg@britannica.bec.de>
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Subject: Re: playing audio CD's on modern laptops
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On Sat, Jun 04, 2005 at 03:47:42PM +0200, Hans Petter Selasky wrote:
> Why is PIO mode not selected automatically by the ATAPI driver? Hence 
> obviously some manufacturers try to save money here, not supporting all modes 
> for all mediums? UDMA works for data CD-ROM's though.

(a) Because it adds a lot of overhead for normal operation e.g.
playing a DVD.
(b) Because not all drives are unable to correctly implement it,
for many ATAPI-DMA and CDDA works fine.

BTW, you can always switch without rebooting, atacontrol(8) is your friend.

Joerg