I used to have the same problem, but it has been so long since I messed with it I can't remember. Try putting in 0 NOEMS. I think also MemMaker? in DOS might help. Anyway I got this game working in the new Dosbox .72 with sound even! But get this GNB 5 does not work with sound even though it was a newer game! Anyone fix this with the new Dosbox?
