ATAPI & UDMA? [Re: (U)DMA Explained]

Vojtech Pavlik (vojtech-lists@twilight.ucw.cz)
Fri, 23 Oct 1998 11:53:17 +0200


On Thu, Oct 22, 1998 at 10:34:49AM -0500, Andre M. Hedrick wrote:

> A trailing tag with UDMA is considered, 100% native.
> A trailing tag with (U)DMA is considered, native capable (forgot to enable)
> A trailing tag with DMA is considered, straight Multi/Single Word native.

I have a question: I have an UDMA ATAPI CD-ROM, and a VIA MVP3. The bios
does find and report the CD-ROM as an UDMA drive, and everything is fine
there. Linux doesn't say a word about it, but I guess that's because
it only can do that for the haddrives. The CD-ROM is a 36x speed,
and does only 2.6 MB/sec under Linux ... so I doubt it's running UDMA,
unless the manufacturer lies about the true speed of the CD-ROM.

Now, how to check if the CD-ROM is running in UDMA mode?

Vojtech

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