INTO             Interrupt on Overflow               Flags: O D I T S Z A P C
0 0

Logic:    if (OF = 1)
PUSHF              ; Push flags onto stack
TF   0             ; Clear Trap Flag
IF   0             ; Disable Interrupts
CALL FAR (10h)     ; The INTO vector is at 0000:0010h

INTO activates interrupt type 4 if the Overflow Flag is set; otherwise
it does nothing. This interrupt operates identically to an "INT 4" if
the overflow flag is set, in which case INTO pushes the flags
register, clears the Trap and Interrupt-enable Flags, pushes CS and
IP, then transfers control to the interrupt-num 4 handler, which is
pointed to by the vector at location 10h.  If the interrupt handler
returns using an IRET instruction, the original flags are restored.

Operands                  Clocks   Transfers  Bytes   Example
no operands              53 or 4       5        1     INTO

Notes:         The flags are stored in the same format as that used
by the PUSHF instruction.

INTO can be used after an operation that may cause
overflow, to call a recovery procedure.

See also: INT
See also: IRET
See also: JNO
See also: JO
See also: PUSHF
See also: CALL
See also: INT 04h
See also: Flags

INTO Interrupt on Overflow