A.5.122 INT: Software Interrupt
INT imm8 ; CD ib [8086]
INT causes a software interrupt through a specified vector number from 0
to 255.
The code generated by the INT instruction is always two bytes long:
although there are short forms for some INT instructions, NASM does
not generate them when it sees the INT mnemonic. In order to generate
single-byte breakpoint instructions, use the INT3 or INT1 instructions
(see section A.5.123) instead.