Maybe old news here, but I just discovered this. Best part, it works in real DOS. 😀 I just patched Ultima 3 and Ultima 5 and I have to say this is amazing! If you're a fan of these old Ultimas, do yourself a favor and patch your installs. They took the original music from the Apple and Commodore versions, converted to MIDI, and you can play with any soundcard. General MIDI sounds best, but Sound Blaster sounds great too. Ultima 3 also has the option to update graphics to VGA, EGA, 16 color CGA or 4 color CGA as well as some nice enhancements like being able to quit to DOS. 😀 More info:
Ultima 3: http://exodus.voyd.net/ultima3.html
Ultima 5: http://exodus.voyd.net/ultima5.html

Growing up playing these games on an Apple II with a Mockingboard, the DOS versions always felt lifeless. Now, it's like I'm sitting at my Apple II again. If you played these on the C64, you'll feel the same way.

Enjoy.

BTW, these patches are quite a few years old, so I'm sorry if it's old news to you all.

edit: forgot to mention, they built in a frame limiter too.