Chuck(G)
25k Member
Or NAPLPS, or Teletext.
As mentioned, one legitimate use case of forcing 'well behaved' apps into graphics mode is for charset localization (on CGA), but somehow I doubt that was the motive.
Or Videotex.
As some of the third-party ANSI implementations demonstrate, there is a certain advantage to abstracting the display interface. Scrolling of a text display using normal Int 10h routines on a PC XT was very slow--you moved the entire screen in memory for each newline. On the other hand, if you simply changed the starting location for the display and allowed it to "wraparound", scrolling was very fast. The downside was that the memory location for any line changed every time the display scrolled. A driver could track that position transparently.