Re: UltraDMA/33 support?

Bryn Paul Arnold Jones (
Mon, 26 Jan 1998 13:55:28 +0000 (GMT)

On Mon, 26 Jan 1998 wrote:

> Does Linux support UltraDMA/33 drives properly?
> I just bought a 4.3gig Quantum Fireball SE (the new one), and
> when I partitioned it, the partition table was all screwed up
> looking. The "begin" field did not match the "start" field.
> This drive's geometry is:
> C/H/S=14848/9/63

Ok, we're starting out with it unpartitioned ? You proberbly want to
translate that geometry by dividing the number of cyls by 2 until it's
less than 1024 (ie 1023 or less), and then doubbling the number of heads
that many times.

I'll give an example, my 3.2Gb disk claims CHS 6296/16/63, but fdisk sees
it translated to 787/128/63. 6296/(2*2*2) = 787, 16*(2*2*2) = 128. The
kernel only catches on to the translation when it examines the partition
table, but that could be because the disk isn't on the first IDE channel.

With a CHS of 14848/9/63 I get 928/144/63 using the same methord. If you
start fdisk on the disk as usual, and go to expert mode with the x
command, then use the h command to change the number of heads, and the c
command to change the number of cylinders, and then the r command to
change back to the main menu.

You should be able to partition it coherantly now, and the kernel should
notice the translation (at least after you reboot like your ment to).

> Linux fdisk complains when starting up that this drive has a
> large cylinder count. Does this mean that I just raked out $330
> for a drive I can't use in Linux?

Nope, it's just complaining, it'll complain about dos 6.xx partitions
might not work after you write out the partition table ;).

> If that is the case, does anyone have a projected date of when
> support will exist for my drive? I'm not looking at any
> whiz-bang code that pushes 200megs a second. Even if the drive
> runs slower than molasses in january, I'll be happy so long as it

Well the drive should support mword2 dma, so dma support should work fine ;)

> Anyone?
> Mike A. Harris | Homepage:

PGP Pub key      ID: 1024/30AF2D69
On-line, adj.:         FP: FC 4E 41 9E 64 C3 AB 28 A3 5A 57 F8 CC D9 A7 B8
    The idea that a human being should always be accessible to a computer.