Int 21 Fn 4403  - DOS 2+ - Ioctl - Write To Character Device Control Chan  [D]

   AX = 4403h
   BX = file handle referencing character device
   CX = number of bytes to write
   DS:DX -> data to write

Return: CF clear if successful
       AX = number of bytes actually written
   CF set on error
       AX = error code (01h,05h,06h,0Dh) (see AH=59h)

Notes: format of data is driver-specific (see below for some specific cases)
   if the file handle refers to "4DOSSTAK", the 4DOS (v2.x-3.03)
     KEYSTACK.SYS driver will push the specified characters on the
     keyboard stack; similarly for "NDOSSTAK", the NDOS KEYSTACK.SYS
     driver will push the characters onto the keyboard stack

See Also: AX=4400h,AX=4402h,AX=4405h,INT 2F/AX=122Bh,INT 2F/AX=D44Dh

See Also: INT 2F/AX=D44Fh