Determines whether a character is ready for input, returning a flag and also the character itself, if one is waiting.
Call with:
AH = 11H
Returns:
If key waiting to be input
Zero flag = clear
AH = keyboard scan code
AL = character
If no key waiting
Zero flag = set
Notes:
Use this function for the enhanced keyboard instead of Int 16H Function 00H. It allows applications to test for the additional F11, F12, and cursor control keys.
The character returned by this function when the zero flag is clear is not removed from the type-ahead buffer. The same character and scan code will be returned by the next call to Int 16H Function 10H.