this is what the read ne in install says.............
About the Smart Boot Manager image
The file `sbm.bin' that is available in this directory may be useful
to you if you are not able to directly boot the first CD because your
BIOS may be too old and may not support ISOLINUX.
Then, instead of booting on the CD directly, you create a Smart Boot
Manager floppy image by using the sbm.bin disk image. You can create this
floppy with rawrite (under DOS) or with dd (under Linux). Now you can
boot on this floppy disk and it will detect your CDROM and let you boot
on it bypassing any BIOS limitation.
What is SBM ?
Smart Boot Manager or briefly SmartBtmgr (SBM), is an OS independent
Boot Manager - a program that is loaded by the bios before any
operating system and allows you to choose which operating system to
SBM is included in Debian in two ways, the package bmconf allows us to
install and configure an old version of SBM and sbm wich is the latest
version of SBM with an installer.
What's the use of SBM on the CD then ?
SBM includes an IDE driver that allows us to boot the cds even on
machines with a BIOS that wouldn't support booting from CD, provided our
CDROM is an IDE one, that is, so you can make a SBM floppy and boot from
it and then tell it to boot from your CDROM.
Also, there are some cases where the BIOS would allow booting from the CD
but isolinux fails to boot from there, in this case you can either boot
using a CD other than the first, as the others don't use isolinux, or you
can make a SBM floppy and boot from this floppy and then tell SBM to boot
How do you make a SBM floppy ?
If you have SBM installed on a box you can run sbminst. Otherwise you can
put the sbm.bin floppy image that we provide with our cds onto a floppy
just like you would do with a rescue image.