There actually are several questions related to my hard drive.
1. during the boot time BIOS says my HDD is "LBA ATA100 120Gb". Do I have to pass any parameters to kernel in order to use that "100". AFAIK, the default is 33. I can increase this to 66 by adding something like "idebus=66" to the "kernel" string in GRUB's menu. I can well be missing [mixing up] something.
2. dmesg says no DMA found. hdparm says dma is not enabled (and I can't enable it). reiserfsck warns about the same thing. All this makes me think that the motherboard does not contain a particular piece of hardware (what does "dma" look like, anyway? - is it "sotf" or "hard"?)

Vitalie Ciubotaru