the I can't remember about DS and DS$, but these may use some formerly unused page 0 locations. I do recall though that the 8000 series used the former table screen line status bytes (whether the first or second half of an 80-character line), which was not needed when screen lines were 80 character anyway, for a lot of things used in the new screen management routines. The Fat 40, however, did need the screen line status bytes, and stuck the screen management junk at the end of the 2nd cassette buffer. So Cassette #2 can only be used for loading and saving programs on the fat 40. Other data gets corrupted. Anyway, West should contain it all, so best of luck when you get your copy... Philip.