Compatibility: ◄Undoc► ?? 
 Expects: AL    character to display
 Returns: ??    undocumented

    Info: This is ◄undocumented► through DOS 6.0 and I can't find much
          about it.

          INT 29H outputs a character to the screen.  When ANSI.SYS is
          resident, it intercepts this vector; otherwise, it is handled
          internally by DOS.

          My disassembly shows that the routine fetches the current screen
          color into BL and then passes AL on to INT 10H 09H (write
          character).  It updates the cursor position.  It also appears to
          take special action on:

            07H BEL (make a beep; don't update cursor)
            08H BS  (backspace; cursor backwards one column)
            0aH LF  (line feed; cursor to next line; scroll if needed)
            0dH CR  (carriage return; cursor to start of line)
            1bH ESC (ANSI Escape Sequences)

          This fn is NOT particularly fast, compared to hand-optimized
          writes directly to video memory.  In fact,  I can see no
          advantage over using, say INT 10H 0eH.  However, it is a bit
          faster than handle-oriented file output to the CON device.

See Also: Character I/O Functions
          INT 2fH 1a00H (is ANSI installed?)
          ANSI Escape Sequences
          DOS Interrupts