Thanks to everybody who replied to my previous inquiry about booting Ubuntu in text mode. Eventually, I managed to figure out a solution, sort of, after combining several of the tips.
Much of the advice was sound but didn’t really apply in one way or another. For example, Ubuntu 11.04 uses GRUB2, which apparently differs significantly from the old GRUB. This means that many of the proposed solutions didn’t apply (unless I had reinstalled using the old GRUB, I don’t know). There’s no /etc/inittab, no menu.lst, editing the boot menu works differently, the vga= parameter is no longer supported, etc.
The Ctrl-Alt-F1 (etc) suggestions sort of worked, but gave me the same small font, plus I really wanted the system to *start up* in text mode.
The reason I chose Ubuntu in the first place was because it’s popular. My Secret Project (oh, the suspense ;-) involves building something on top of an Unixoid system, and Ubuntu seemed like a logical choice; it’s very actively developed, has drivers for a lot of hardware, etc. But on second thought, it might not have been a good choice for my purposes. Ubuntu strives to provide a smooth, user-friendly experience, which implies a desktop GUI. Support for terminals that boot up in text mode is, understandably, not their first priority.
However, there *are* Linuxen with different priorities. As reader “Kerobaros” pointed out in a comment, ArchLinux may be a better choice. So after a lot of fruitless experimenting with all the advice mentioned in the other comments, I decided, what the heck, I’ll give it a try. (It uses the old GRUB, so that made things easier as well.)
At first it did the same thing as Ubuntu: I could set the VGA mode/resolution in GRUB, and it would start up using that mode, but at some point during the booting process the screen would fall back to the 1024×768-based font. (I figure most people would actually prefer that font, since it’s much more crisp, and more text is visible on the screen, but for my old eyes, it’s not so good.)
Then eventually I read somewhere that this behavior is something that newer kernels do, and that the nomodeset option stops it from happening. It didn’t actually do that on Ubuntu 11.04, but it did on ArchLinux. So now I finally have a Linux install that sets the right font (80×25) and *keeps* it. ^_^
I did offer a bounty to the person who could solve this problem. Oddly enough, the “golden tip” turned out to be the suggestion to use Arch Linux. Several people mentioned “nomodeset”, and while it didn’t have the desired effect on Ubuntu, it does work properly with Arch. Given that I couldn’t get any of the other tips to work with Ubuntu 11 at all, I think that Kerobaros should get his pick of the prizes, if he/she wishes.