List of Useful Interrupt Subfunctions

Interrupt. SubFunction. Input. Output.
10h (VIDEO INTERRUPT) 00 (SET_MODE)
Sets the Video mode
AL=mode number
-
-
0Ch (WRITE_DOT)
Puts a dot on the screen
Graphics modes only
DX=row
CX=column
AL=colour
-
0Dh (READ_DOT)
Reads a dot on screen
Graphics modes only
DX=row
CX=column
-
AL=colour
-
-
16h (KBD_IO) 00 (AWAIT_CHAR)
Reads a character from keyboard
- AL=character
AH=scan_code
01 (PREVIEW_KEY)
Checks to see if a key is ready
Does not remove key from buffer
- Zero flag set - key ready
AL=character
AH=scancode
21h (DOS_INTERRUPT) 01 (KEYBOARD_INPUT)
Reads and displays one character
- AL=character read
-
02 (DISPLAY_OUTPUT)
Displays one character on screen
DL=character
-
-
08 (NO_ECHO_INPUT)
Same as 01 but not displayed
- AL=character
-
09 (PRINT_STRING)
Displays a string on screen
String must end with "$"
DX=address of string
-
-
-
0A (BUFFERED_INPUT)
Reads a string from keyboard
DX=address of buffer
First character=max length
-
Second char of buffer=length of input
Rest of buffer=input string
followed by carriage return (0Dh)
4Ch (EXIT) AL=exit code -