DOS / Interrupts / 29

                        Interrupt 29h   FAST PUTCHAR

Input	DOS1	N	DOS2	Y	DOS3	Y	DOS5	Y	Output
AX			Character						AX
BX									BX
CX									CX
DX									DX
ES:DI									CF

     This  method   is  extremely  fast  (much  faster  than  DOS  21h
     subfunctions 02h and 09h,  for  example), and it is portable, even to
     "non-compatible" MS-DOS computers.

Notes:

     1)   Documented  by Digital Research's DOS Reference as  provided
          with the DEC Rainbow

     2)   If ANSI.SYS  is  installed,  character  output  is  filtered
          through it.

     3)   Works on the IBM  PC  and  compatibles,  Wang PC, HP-150 and
          Vectra, DEC  Rainbow,  NEC  APC,  Texas  Instruments  PC and
          others

     4)   This interrupt is  called  from the DOS's output routines if
          output  is going to a device rather than  a  file,  and  the
          device driver's attribute word has bit 3 (04h) set to "1".

     5)   This call has been tested  with MSDOS 2.11, PCDOS 2.1, PCDOS
          3.1, PCDOS 3.2, and PCDOS 3.3.

     6)   Used  in  IBMBIO.COM  as  a  vector to int 10, function  0Eh
          (write TTY) followed by an IRET.