The following table summarizes the main I/O functions. These functions are used to
read a character or a string from the keyboard and display it on the screen.
They are used to input data to a program, and display characters or strings,
which could be the output of the program.
|Function||Input in ||Effect
|01H ||AH ||Read a character with echo on the screen and store it in AL.
|02H ||AH,Character in DL ||Display the character given in DL on the screen. AL=Character Displayed.
|06H ||AH,Character in DL ||Same as function 02 but interrupted by Ctrl + Break.
|08h ||AH ||Read a character without echo and store it in AL.
|09H ||AH, offset in DX ||Display the string terminated by a ‘$’ sign, starting at the address given in DX.
|0AH ||AH, offset in DX ||Read a string of characters from the keyboard and store it at the address given in DX.
Table: Simple I/O DOS function calls