<sect>Video Code
<p>
I have largely reorganized the video code. Be aware that a lot of code
is now in a different place, and some files were moved or renamed.

<sect1>C files
<p>
<descrip>
<tag>video/video.c</tag>    global variables, init/cleanup code
                  video_init(), video_close(), load_file(),
                  video_config_init()

<tag>video/int10.c</tag>    int10 emulation (formerly int10.h), Scroll, 
                  clear_screen, char_out, set_video_mode

<tag>video/vc.c</tag>       console switching code (formerly video.c)
<tag>video/console.c</tag>  console mode routines

<tag>video/et4000.c,
video/s3.c,
video/trident.c</tag>  card-dependent console/graphics switching routines

<tag>video/vga.c</tag>      console mode? graphics?

<tag>video/terminal.c</tag> terminal mode video update routines (ansi/ncurses)

<tag>video/X.c</tag>        Xwindow stuff
</descrip>

<sect1>Header files
<p>
<descrip>
<tag>video/vc.h</tag>       def's relating to console switching 
                  (formerly include/video.h)

<tag>include/video.h</tag>  def's for general video status variables and functions
</descrip>

<sect1>Notes
<p>
<itemize>
<item> we now have 'virtual' video support. Every video front-end defines a
  static, initialized structure 'Video_xxx' (e.g. Video_console)
  which contains (mostly) pointers to the appropriate routines
  for certain tasks. 
<p>  Please use this when implementing new video front ends!
  (See video/video.h for more info)
<item> most of the video code & defs is removed from emu.c and emu.h
  (now mostly in video/video.c)
<item> int10.h no longer exists (now in video/int10.c)
<item> sigalrm now again checks the dirty bit(s) in vm86s.screen_bitmap
  before calling update_screen.
<p>
  At the moment, it doesn't seem to achieve much, but it might help
  when we use mark's scroll detector, and will be absolutely necessary
  for a good X graphics support.
<p>
  Note that for all video memory modifications done outside of vm86
  mode we must now use set_dirty()  (defined in int10.c).
  <em>this is currently disabled. To enable it, set VIDEO_CHECK_DIRTY
  to 1 in include/video.c.</em>
</itemize>

<sect1>Todo
<p>
<itemize>
<item> cleanup terminal/console mode initialization
  (currently called from video_init() in video.c)
  termioInit(), termioClose() should probably be split 
  up somehow (i.e. general/terminal/console)
<item> fix bug: screen is not restored properly when killing dosemu
  in graphics mode
<item> properly implement set_video_mode()   (int10.c)
<item> cursor in console mode ok?
<item> put int10.c into video.c?
<item> put vc.c into console.c?
</itemize>
