Compatibility: 1.0+
Expects: AH    0bH
Returns: AL    0ffH if a character is available from the Standard Input
0    if no character is available
Info: Checks the status of the Standard Input.

If Ctrl-Break is detected, INT 23H is executed.

Notes:   Use before Fns 01H, 07H, and 08H to avoid having DOS wait for a

  This is a simple, non-destructive way to check for Ctrl-Break
during long calculations or other processing that does not
normally look for input.  It lets the user abort from such a

See Also: INT 16H
- -

DOS Fn 0bH: Check Input Status