Int 21 Fn 33 - Dos 2+ - Extended Break Checking [D]
AH = 33h
AL = subfunction
00h get current extended break state
Return: DL = current state, 00h = off, 01h = on
01h set state of extended ^C/reak checking
DL = new state
00h off, check only on character I/O functions
01h on, check on all DOS functions
Return: (Novell DOS 7) DL = old state of extended Break checks
Note: under DOS 3.1+ and DR DOS, this function does not use any of the
DOS-internal stacks and may thus be called at any time
See Also: AX=3302h