Well, my only experience with DosBox so far is Syndicate Wars. I learned that menus run differently from the game itself. In SW, the menus run at cycles=17500 and the game runs at cycles=80000. To get there, set cycleup=10000 and hit ctrl+F12 to increase speed.

If U6 menus are running too fast, set cycledown=whatever and hit ctrl+F11 to decrease speed. It may be running too fast. I beat U6 as a kid so I'm not going to try it again soon 😀 If you like U6, try Savage Empire and Martian Dreams as well. Truly the best games of all-time.

Check the comments on Syndicate Wars for other settings, like output=ddraw, xms=16/32/64 etc. I bet you can get it to work.

I have no idea, mine works just fine. The fade-in/fade-out transition is a little slow, but I'm used to that (it's like that in every game I have, that I can think of off hand.) Are you sure the rest of the game is at the correct speed? I based mine on the speaker sounds (do they sound close to what they represent, how do spells look/sound when cast, etc...) I don't have access to my main computer right now or I'd attach my config file.

It's mostly the television screen that is way too fast. Everything else seems fine. Unlike the rest of the game, though, the intro is not speed-limited.

Well, it's not only the TV screen, but the whole intro animation running too fast (the scrolling to the window, the clouds drawing nearer, the lightning that strikes the circle of stones in the garden,...).

@FeedingDragon: Yes, speed is correct, I run it at 2000 cycles. That comes close to what (I recall) it was like on my old 286. The game itself is working well, speaker sounds, walking speed etc.

It's only the intro sequence that's messed up a bit. Like I said, it's not a major problem as it doesn't influence the game itself, but I still find it rather strange, considering it was alright up to v0.58.
I can only guess that it has something to do with the improvements in graphics emulation (😕?)

Now that you mention it, I'm not sure I've actually tested U6 with any recent DOSBox. I set everything up back with 0.5? (not sure which exact version it was,) then started playing them all from the beginning. I'm only about half way through U4 now. Yes, I'm going fairly slow, not playing as much as I did when they first came out, and I'm taking a lot of notes this time.

I've played U6 so often, I know that effect by heart. It happened on real hardware in exactly the same way, for example on my old 486. As was previously said, some parts of the animations are not rate-limited, so they run as fast as they can. You need to reduce speed even more, try 1000 or 700 cycles. And then use that neat trick with "cycleup=<difference between low and high speed>" gigawing2 suggested.

I've found a very simple and quite strange solution: I was playing U6 with normal core all the time, setting core=dynamic fixed the problem. 😕
I have no idea why, but somehow the animations run about 4-5 times faster when using normal core. Interesting...

Sounds like there is a timing loop at last, but it might be using some instruction that's slower than others in normal core, so timing gets wrong. Since my 486 I posessed back then had an AMD CPU, it might be the same effect, different timing than true Intel CPUs