Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

   ◄Summary►  ◄Detail►  ◄Key to Flags►
──────────────────────────────────────────────────────────────────────────────
 
Output String to Port                            Flags:  O D I T S Z A P C
                                                         ═════════════════
80186/286/386 Only
 
Syntax:  OUTS DX,src
         OUTSB
         OUTSW
 
  Sends a string to a port. The string is considered the source and must
  be pointed to by DS:SI (even if an operand is given). The output
  port is specified in DX. For each element sent, SI is adjusted
  according to the size of the operand and the status of the direction
  flag. SI is increased if the direction flag has been cleared with
  CLD or decreased if the direction flag has been set with STD.
 
  If the OUTS form of the instruction is used, an operand must be
  provided to indicate the size of data elements to be sent.  A segment
  override can be given.  If OUTSB (bytes) or OUTSW (words) is used, the
  instruction determines the size of the data elements to be sent.  No
  operand is allowed with OUTSB or OUTSW.
 
  OUTS and its variations are usually used with the REP prefix. Before
  the instruction is executed, CX should contain the number of elements
  to send.
                                    -♦-