Thanks, Driver. Your hint put me on the trail to the solution, part of which at least was there on my Suse installation.
The documents themselves were not really any help, though. Perhaps if I would have spent the afternoon reading and digesting them, but I doubt it.
I found /etc/lilo.conf on Suse, left by one of my failed attempts, I believe, and got the Suse stanza info out of that.
My first attempts were rejected by the system; then I found out at the web site troubleshooters.com/linux/lilo.htm that I had to mount the Suse partition in Mandriva's /mnt directory, and put that address in lilo.conf. So it looks like this:
append=" showopts resume=/dev/hda8 splash=silent"
What seems odd to my incomplete understanding of the system is that the boot process continues to find /mnt/suse/boot/ every time, although that directory is not yet permanantly set to mount (in /etc/fstab), and so that drive is not found by, for example, the gui, after rebooting, without mounting it by hand again.
It also seems odd to me that instructions on how to do this were not easier to find, for surely systems running multiple Linux distros are relatively common.