More information on the subject can be found, for example, in The REAL Multiboot.
When Windows NT is installed after DOS was installed, the existing DOS boot sector is overwritten with the NT boot sector. But immediately before that, the DOS boot sector is copied to a file BOOTSECT.DOS (usually in the root of C:).
Windows NT/2000 Multiboot
When MS-DOS is selected from the NT boot menu, NTLDR runs BOOTSECT.DOS, which in turn loads IO.SYS, loading DOS.
From the Oberon point of view, this boot manager can be installed on a new, bare hard disk which will host only DOS in the first primary partition and any number of Native/Active Oberon partitions (primary or logical).
The installation can be conducted with Oberon facilities in a hand's turn, provided a source machine with a Windows/DOS combination is available.
On the source machine:
[boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(3)\WINNT [operating systems] multi(0)disk(0)rdisk(0)partition(3)\WINNT="Microsoft Windows 2000 Professional" /fastdetect C:\ = "MS-DOS" C:\dev#part.MBR = "ETH Oberon / PC Native dd.mm.yy"
Here is a workable grub file for dual booting Linux and Bluebottle submitted by Alan Freed - Alan.D.Freed at nasa.gov
# grub.conf generated by anaconda # # Note that you do not have to rerun grub after making changes to this file # NOTICE: You have a /boot partition. This means that # all kernel and initrd paths are relative to /boot/, eg. # root (hd0,0) # kernel /vmlinuz-version ro root=/dev/hda3 # initrd /initrd-version.img #boot=/dev/hda default=1 timeout=10 splashimage=(hd0,0)/grub/splash.xpm.gz password --md5 title Red Hat Linux (2.4.18-18.8.0) root (hd0,0) kernel /vmlinuz-2.4.18-18.8.0 ro root=LABEL=/ hdb=ide-scsi initrd /initrd-2.4.18-18.8.0.img title Bluebottle rootnoverify (hd1,0) chainloader +1
Example of application: a boot manager to control 39 separate, fully functional operating systems, including ETH Oberon, on a machine, by Richard Robbins. This site also provides an insight on multiboot solutions and problems.
18 Mar 2003 - Copyright © 2003 ETH Zürich. All rights reserved.