When I wanted to install Debian on an old P2, I couldn't boot from the CD because the old bios didn't support it. I instead used a script called 'debootstrap' on a working machine with a net connection. My host OS was Gentoo and debootstrap was available in portage:
* dev-util/debootstrap
Available versions: 0.2.41 0.2.45 0.2.45-r1 !0.3.2.2
Installed: 0.2.45-r1
Homepage: http://packages.qa.debian.org/d/debootstrap.html
Description: Debian bootstrap scripts
The 'debootstrap' script builds a minimal Debian system which you can chroot into. Once chrooted into the Debian environment, I used 'aptitude' to install a i386 kernel image into /boot. I then exited the chroot environment and used the host OS to burn the Debian filesystem to a cdrom.
I was now ready to boot the P2 with using a boot floppy (tomsrtbt). Once booted, I mounted and then copied the contents of the cdrom over to the hard disk. The last step was to set up the bootloader on the HD. To do this, I chrooted into my new Debian install and used 'lilo' to set up the MBR. That's it! I was able to reboot the machine and load up Debian.