I tried several things and help, again, is appreciated. @erik, @cinap: 9front and 9atom booted properly. 9atom live-boot option didn't work, but installation proceeded to [mountdist]. At that point I couldn't figure out a way to point it correctly to the distribution, my linux partition, though suggested, wouldn't mount. I had a plan9.iso there. Before that at [partdisk] I manually specified a 3GB partition in some raw free space I had. So I aborted, and then on I cannot boot into Linux (I had backed up, so no worries). Why should the existing linux boot partition get spoiled? Booting in with a rescue CD (Ubuntu Rescue Remix), I can 'fdisk -l' all the partitions as they were. The NTFS partition (I have Windows installed), and other ext3 partitions can be mounted and navigated except for the boot partition (where root was mounted).
@Thiery, I could key in characters at the 'boot from' prompt, but didn't try anything then. I have a MBR, not GPT. It's a typical dual- boot layout, having installed Ubuntu second, after Windows.
