Opening an Intuition screen in one of the new modes requires the
specification of 32 bits of mode data.  The newscreen.viewmodes field is a
UWORD (16 bits).  Therefore, the new Release 2 function openscreentags()
must be used along with a SA_DisplayID tag which specifies the 32-bit
ModeID.  See the "intuition screens" chapter for more on this.

The new display modes also introduce some complexity for applications that
want to support "mode-sensitive" processing.  If a program wishes to open
a screen in the highest resolution that a user has available, there are
many more cases to handle under Release 2.  Therefore, it will become
increasingly important to algorithmically layout a screen for correct,
functional and aesthetic operation.  All the information needed to be
mode-flexible is available through the display database functions
(explained below).