Int 2F Fn 120A  U - DOS 3+ Internal - Perform Critical Error Interrupt     [D]

   AX = 120Ah
   DS = SS = DOS DS (must be using a DOS internal stack)
   STACK: WORD extended error code

Return: AL = user response (0=ignore, 1=retry, 2=abort, 3=fail)
   CF clear if retry, set otherwise
   STACK unchanged

Notes: can only be called during a DOS function call, as it uses various
     fields in the SDA to set up the registers for the INT 24
   reportedly sets current DPB's first root directory sector to 1

See Also: INT 24