The INT 04H vector can be used as one way to minimize the size of programs

that perform a lot of arithmetic operations.

After any arithmetic operation, the INTO instruction will test for

arithmetic overflow, and if the CPU flag is set (OF=OV=1), then INT 04H

is executed.

You might see code such as:

mov ax,var_1

add ax,var_2

into ;2-byte test for arithmetic overflow

... etc. ... ;either no overflow or it has been handled

; by the interrupt handler

See Also: INT 00H (division by 0)

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