Part of the screen goes black sometimes when encountering invisible NPCs or reading a scroll of magic mapping. Happens all the time to me in Water Dragon Cave and just happened to me in ToEF when I read a magic mapping scroll. Cannot see around me, but I see the mini-map just fine so I was able to navigate out of the level. Came back and the screen was still black. Saved the game and reopened, the screen was still black.

I am playing ADOM Release 60 on a MacBook.

Thanks!