INT 29 - DOS Fast Character I/O (Undocumented 2.x+)

AL = character to write

returns nothing ???

- used by DOS device drivers to output data to the screen if

bit 4 of the device attribute word is set

- similar to ~INT 21,2~ and ~INT 21,9~ but much faster

- simply calls the BIOS ~INT 10,E~ in DOS versions 2.x and 3.x

- advances the cursor after character output