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out of date.
INS/INSB/INSW
◄Summary► ◄Detail► ◄Key to Flags►
──────────────────────────────────────────────────────────────────────────────
Input from Port to String Flags: O D I T S Z A P C
80186/286/386 Only ═════════════════
Syntax: INS dest,src
INSB
INSW
Receives a string from a port. The string is considered the destination
and must be pointed to by ES:DI (even if an operand is given).
The input port is specified in DX. For each element received, DI
is adjusted according to the size of the operand and the status of the
direction flag. DI is increased if the direction flag has been cleared
with CLD or decreased if the direction flag has been set with STD.
If the INS form of the instruction is used, a destination operand must
be provided to indicate the size of the data elements to be processed
and DX must be specified as the source operand containing the port
number. A segment override is not allowed. If INSB (bytes) or INSW
(words) is used, the instruction determines the size of the data
elements to be received. No operands are allowed with INSB or INSW.
INS and its variations are usually used with the REP prefix. Before
the repeated instruction is executed, CX should contain the number of
elements to be received.
-♦-