| AH=01h | Read A Character |
| AH=02H | Write/Print A Character |
| AH=09H | Write/Print a String |
| AH=0Ah | Buffered keyboard input. |
| AH=2AH | Get System Date |
| AH=2BH | Set System Date |
| AH=2CH | Get System Time |
| AH=2DH | Set System Time |
| AH=3CH | Create a File |
| AH=3DH | Open a File |
| AH=3EH | Close a File |
| AH=3FH | Read From File |
| AH=40H | Write to File |