It took a while but I finally found where Dune draws the talking heads. This is 9 sprites put together.
The game builds a list of the sprites (still working on how), and if I copy the list from my emulator, “Duke Leto, your father” show's up.
I spent a long time on how the game reads the lip sync data that's in the .voc-files, but Dune completely ignores that when audio is not enabled – and my emulator doesn't have audio yet…
