INT 23h (35)             Break Address

    Contains the address to which control is passed in response to a
    Break-key action. When a program is executed, DOS copies this address
    into offset 0Eh through 11h of the Program Segment Prefix.

    The Break action is generated either by Ctrl-C or (on the IBM PC
    family and many clones) Ctrl-Break. Normally, DOS checks for a Break
    only during character I/O functions. With extended Break checking in
    effect (see Interrupt 21h, Function 33h), DOS checks for Break during
    any I/O function.