Well, Flash Ultima 4 turned out to not last half as long as I expected... Back in '86, a release with the best graphics & music available to consumers ran well on computers even 2-3 years old. Upgrade it to VGA (i.e. graphics for 1990), same music, convert into Flash, and combat is unplayably slow on a 1.6GHz/512MB machine. Lest you forget, that's the same speed as a current netbook.
I looked into the updated version of Ultima IV for modern operating systems, which is called xu4. It appears to be one of the many projects that began as a Linux conversion that gained a lot of steam in Windows. Unfortunately, they stopped updating the binaries for Linux five fucking years ago (though they find the time for OS X).
So I tried the Windows release in Wine... DOSBox happily let me set up the old music/graphics upgrade, and running the old (updated) DOS version went well. However, hitting any key during the xu4 startup sequence crashes it, and even if I do get all the way into the game, there's no fucking sound. I triple-checked my audio settings, but no luck.
I decided on a whim to head for Ultima VI instead, and after very little DOSBox tinkering, had it running really well. I soon found, annoyingly, that it won't let me start a new game or delete my ancient one. It wants me to create a new player disk, which is difficult considering it's all based on files, and I haven't sorted out how to do that. Tried an old utility for the purpose, but being based in DOS, it wanted a hard drive letter...no, I don't want to do that much setup.
So I'm going to fucking make Ultima V run; so far I have the game in DOS, plus sound -- just no music. Just not going to get all the way now, because after a night of increasingly hating people and computers, it's now fucking time for bed. AARRGH.