I started a dual boot system with windows 98se and Fedora core 1. The grub loader from Fedora worked well and I could choose either os. I recently installed Suse 10.0 and found that the new boot loader has no reference to Fedora. The Fedora partitions are:
/dev/hda2 /boot
/dev/hda3 /
If I add a line in the suse boot loader settings for /dev/hda2 the system responds 'invalid or unsupported executable format'. In the grub menu, in place of where Fedora would be listed is:
Floppy /dev/fd0
I have a startup disk. I am assuming I can run the Fedora partion booting up by using the startup disk? So I dont mess up the hard disk, is there a prefered way to boot a multi boot system with a start up disk? I am assuming that I would pop the floppy in when I see the suse grub menu and choose the floppy option? Or if I let the computer boot from the floppy, will it automatically detect the Fedora partition and boot it up?

Why dont you edit your grubmenu with suse's Yast ( I think it's under system configuration.)

I would suggest you do this:
open a command shell and login as root and Yast's system configuration (where there is the bootloader option) Then:
Now browse to the folder /boot in FC5, not SuSe!! Open the file grub.lst or something like that. And see what the boot options are. Example:
copy the whole text from title Fedora core to the beginning of title Windows.

Then paste it into the utility SuSe uses to alter the boot files. I'm not using SuSe right now, so I can't say how you exactly find it.

Fiddle around! and voila! there you are!!

p.s. I will give you the exact directions, right after I install SuSe 10.1

The boot loader settings in Suse 10.0 are:
1. Clone
2. kernel (linux)
3. kernel via xen
4. other system (chainloader) (for an os like windows)

When using kernel (linux), it wants to know where the kernel and root are as well as a ramdisk and other boot options. I would assume hda3, since hda2 is the /boot, however, boot loader did not agree with me. I can browse those partitions inside boot loader settings. I also tied under radio button 'other', propose and merege with existing grub menus. It did not add a Fedora entry. I am stuck. How is your luck?

OK I've just done this to my suse 10 instalation, you have to modify the /boot/grub/menu.lst file, looks like yast will do it, but I've never used it so I did it the way I know.
As previous poster sugested, copy your core 1 /boot/grub/grub.conf entry and paste on to the end of suse /boot/grub/menu.lst file, then when you boot up you should get the suse menu + core1 and windows. You'll need to be logged in as root so be careful!!!
This is what my suse file looks like now, your's wont be quite the same because your core1 and windows partitions will be different. ----

# Modified by YaST2. Last modification on Mon Mar 13 08:24:06 UTC 2006

color white/blue black/light-gray
default 0
timeout 8
gfxmenu (hd0,5)/boot/message

###Don't change this comment - YaST2 identifier: Original name: linux###
title SUSE LINUX 10.0
root (hd0,5)
kernel /boot/vmlinuz root=/dev/hdb6 vga=0x31a selinux=0 resume=/dev/hdb5 splash=silent showopts
initrd /boot/initrd

###Don't change this comment - YaST2 identifier: Original name: Debian GNU/Linux, kernel 2.4.27-2-686 (/dev/hdb1)###
title Debian GNU/Linux, kernel 2.4.27-2-686 (/dev/hdb1)
kernel (hd0,0)/boot/vmlinuz-2.4.27-2-686 root=/dev/hdb1 ro
initrd (hd0,0)/boot/initrd.img-2.4.27-2-686

###Don't change this comment - YaST2 identifier: Original name: floppy###
title Floppy
chainloader (fd0)+1

###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- SUSE LINUX 10.0
root (hd0,5)
kernel /boot/vmlinuz root=/dev/hdb6 vga=normal showopts ide=nodma apm=off acpi=off noresume selinux=0 nosmp noapic maxcpus=0 edd=off 3
initrd /boot/initrd

#pasted from core4 13/5/06
title Core 3 (2.6.12-1.1381_FC3)
root (hd1,1)
kernel /vmlinuz-2.6.12-1.1381_FC3 ro root=/dev/hda3 rhgb quiet
initrd /initrd-2.6.12-1.1381_FC3.img
title XP
rootnoverify (hd1,0)
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1

If I understand the posts correctly, I need to mount the Fedora partition, log in as root, open a text editor and copy the Fedora boot info. Then paste the info into the end of Suse's yast boot loader file? I have a Fedora startup disk and this is a copy/paste from the boot disk syslinux.cfg file:

default linux
prompt 1
display boot.msg
timeout 100
label linux
kernel vmlinuz
append initrd=initrd.img rhgb root=/dev/hda3

The kernel is 2.4.22.

After examining the above copy/paste, is the boot disk designed to make the box boot into the correct partition (bypassing the yast boot loader)? And, is the above copy/paste enough info to append to my suse boot loader file using your Fedora copy/paste as a template?

Yes, you've got it.
But now I'm worried by the xen reference in your boot loader. I've just read a magazine article on it. That's a virtual machine program, if it's got into the act, I'm way out of my depth. Trouble is I'm no expert, just coming to terms with multibooting myself, so I can't give you in depth advice, only what I managed to getworking myself.
And no I don't think the startup disk info is quite enough, you'd be much better off with what's actually on Fedora's /boot/grub/grub.conf.
I think the boot disk is used when the operating system doesn't have an entry on the mbr, as is now the case with your core1, so yes you should be able to boot into core1 with it. Have you tried????
You'll need to make sure the floppy is set as the first boot device in your bios, I'm not sure about selecting floppy from the suse boot menu.
But that wont get you into windows, as it also bypasses the core1 boot menu.

Are you comfortable using a text editor to change files? vi or vim both work in suse, but they're not very intuitive to use at first, if you're not used to editing config files, might pay to practise first.

If you do man grub, that's got a detailed description of the whole boot process and how to modify it, including the start up disk.

Yes, I have used vi to edit the config file in Fedora core 1 so I could load the nvidia video driver. As you suggested, I did practice on a copy of the file before doing the actual editing. To do the editing, I had to go to runlevel 3, the vga text mode as root to do the editing. I will attempt the boot loader editing once I am sure I understand what I need to do.

The boot disk works! The floppy reference in the suse grub loader does not work (boot error). I have a feeling that the suse floppy loader is looking for suse specific files. Since it booted into the Fedora partition, I am going to browse to the boot loader file and copy it so the suse bootloader can be updated.

Ok, here is the copy/paste grub.conf file:

# 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 (hd0,1)
# kernel /vmlinuz-version ro root=/dev/hda3
# initrd /initrd-version.img
#boot=/dev/hda
default=1
timeout=10
splashimage=(hd0,1)/grub/splash.xpm.gz
title Fedora Core (2.4.22-1.2115.nptl)
root (hd0,1)
kernel /vmlinuz-2.4.22-1.2115.nptl ro root=LABEL=/ rhgb
initrd /initrd-2.4.22-1.2115.nptl.img
title DOS
rootnoverify (hd0,0)
chainloader +1

From the copy/paste, how much info is needed to edit to my suse boot loader file?

Well done, looks like you're almost there! This is the bit you need, good luck! --

title Fedora Core (2.4.22-1.2115.nptl)
root (hd0,1)
kernel /vmlinuz-2.4.22-1.2115.nptl ro root=LABEL=/ rhgb
initrd /initrd-2.4.22-1.2115.nptl.img
title DOS
rootnoverify (hd0,0)
chainloader +1

That did it! After editing the menu.lst file, it now boots from grub. The grub.conf from Fedora has a title DOS line. Is that ms dos from the Windows partition?

Have you tried selecting it to find out??
I guessed it was your windows instalation, detected by core1 when you installed it.
I was going to suggest you edit it to say "windows" I hope that I'm right and it does boot windows for you.
Cheers Mike