Way back I set up a machine with three OS, MSDOS was the lowest sector.

Don't remember everything I did, but here is my grub.cfg

# menu.lst - See: grub(8), info grub, update-grub(8)
## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
default 1
timeout 177
color cyan/blue white/blue
#Quantian bootable partition config begins
title Quantian on (/dev/sda6)
root (hd0,5)
kernel /boot/vmlinuz root=/dev/sda6 ro ramdisk_size=100000 init=/etc/init lang=us apm=power-off nomce quiet vga=791
initrd /boot/initrd.img
savedefault
boot
# QUANTIAN bootable partition config ends
# XP bootable partition config begins
title XP on (/dev/sda1)
unhide (hd0,0)
hide (hd0,1)
root (hd0,0)
makeactive
chainloader +1
# Win XP bootable partition config ends
# DOS is in front of XP but was installed later so has a higher SDA number
# DOS bootable partition config begins
title DOS on (/dev/sda2)
hide (hd0,0)
unhide (hd0,1)
root (hd0,1)
makeactive
chainloader +1
# DOS bootable partition config ends

--
Vasos Panagiotopoulos panix.com/~vjp2/vasos.htm
---{Nothing herein constitutes advice. Everything fully disclaimed.}---

Something about MSDOS must be before cylinder 1024?

--
Vasos Panagiotopoulos panix.com/~vjp2/vasos.htm
---{Nothing herein constitutes advice. Everything fully disclaimed.}---