So, finally, in Post #12, you tell us you're not really serious about this, you're just farting about?
/Unsubscribes

I'm quite serious about it. As mentioned, I'd like "to get adapters for the X-Video Extension present" and/or "improve video performance" within this device somehow. That I have other devices doesn't detract from that.

Despite the various feedback I got from running mplayer that I described in post one, I think, as I mentioned in post 14, based on the helpful feedback of people here, that there's nothing more that can be done with this specific card. The program glxinfo indicates that direct rendering is happening, so I think that means the card is working as well as it's possible for it to work. Thus, thread solved.

I did create a screencast of this desktop, showing that, despite the computer's age, it still has the capacity to do a variety of things. As all of us here know, with Linux we need not fall prey to planned obsolescence.

Acknowledging that I threw in the towel on thinking the r128 driver package could be of any use, I did just notice this thread from the Debian mailing list, which states: I saw that the package xserver-xorg-video-r128 is now in the Sid repository. I tried it, but it fails, so for now I'm sticking with xserver-xorg-video-ati. Still, there may be some progress on this driver package in the future.

Just a further note: given that the package xserver-xorg-video-r128 is now being maintained by Adrian Bunk, I did file an addition to the bug report X doesn't start with r128 driver (ATI RAGE) [powerpc] to let him know that its non-working status is what I also experience.