I have dual boot machine with W2k and Slack 9. In W2k all storage devices (hd, DVD and CD-RW - all IDE) work in Ultra-DMA mode (set in "devices" section) without troubles.
In Slack I set DMA mode for hd (with hdparm), but have no idea, how to set it for DVD and CD-RW. Does Slack (or Linux) support DMA for removable storage?
And is this DMA mode I set with hdparm for hd the same as Ultra-DMA in Win? Or should I use any other way to set it? And what with DVD and CD-RW drives?

do a hdparm -i /dev/hdx and you get something like this

Model=Maxtor 4D060H3, FwRev=DAH017K0, SerialNo=D3HCV6YE
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=off
CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=120069936
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-6 T13 1410D revision 0: 1 2 3 4 5 6

on the line UDMA modes: you can see that there is a * that shows what you are using.

Thanks, ronin77, but what with DVD and CD-RW???

Change the x in /dev/hdx to the right letter for the drive.

hda: primary master
hdb: primary slave
hdc: secondary master
hdd: secondary slave

I think hdparm is suitable only for harddrives (that's way "hd" in its name). Probaly won't d do its job for removable.
But maybe I'm wrong?

yes you are wrong ... you can use the -d and -c commands with hdparm to check dma and IO_support on a device respectively..

*edit* and to change them modes also.

If your devices are IDE, even if you are using ide-scsi, hdparm will still work for the drives, just as ronin77 and DrOzz said. There will be portions of the hdparm output that don't apply to CDROM or DVDROM devices, but they will just give you errors while the applicable parts work as normal. Don't worry about it, just ignore the errors and pay attention to the valid output.

Thanks all of you, you were absolutely right.
One of the greatest things in Slack is that we can learn something new near everyday.