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documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

   ◄INT 21H Summary►  ◄Contents►  ◄Index►  ◄INT Instruction►
──────────────────────────────────────────────────────────────────────────────
 
You can perform all the functions below more easily with DOS2 functions.
The services below are documented so you can analyze code written for DOS1.
 
Hex #  Dec #     Name
14H     20       Sequential Read
15H     21       Sequential Write
21H     33       Random Read
22H     34       Random Write
24H     36       Set Relative Record Number
27H     39       Random Block Read
28H     40       Random Block Write
                                    -♦-