ATA hard disk not recognized

[erauch@ai.mit.edu (Erik Rauch)]

I just replaced the stock hard drive in my Power Mac Cube with a new
Seagate Barracuda IV 40 GB hard drive. This is an Ultra ATA 100 (UDMA)
drive that came out a few months ago. It works fine with Mac OS 9 and
X.

However, the Debian install CD (November 2000) doesn't recognize the
hard drive at all. fdisk or any operation on /dev/hda responds with
"Device not configured", and the system log has no error messages or
other mentions of a hard drive; it is not mentioned at all (/dev/hdb,
the DVD-ROM, is).

Previously I installed Debian on this machine from the same CD image,
on the 20GB Maxtor disk that came with it, and had no problems.

/proc/modules and /proc/ide return nothing; /proc/dma says "4:
cascade". modprobe says "Can't open dependencies file
/lib/modules/2.2.18pre21/modules/dep (no such file or directory)".

I would appreciate any suggestions. 
Thanks.
-Erik