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INT is an assembly language instruction for x86 processors that generates a software interrupt. It takes the interrupt number formatted as a byte value.〔(【引用サイトリンク】title=Intel Architecture Software Developer's Manual, Volume 2: Instruction Set Reference Manual )〕 When written in assembly language, the instruction is written like this: : INT ''X''where ''X'' is the software interrupt that should be generated (0-255).Depending on the context, compiler, or assembler, a software interrupt number is often given as a hexadecimal value, sometimes with a prefix ''0x'' or the suffix ''h''. For example, INT 21H will generate the software interrupt 0x21 (33 in decimal), causing the function pointed to by the 34th vector in the interrupt table to be executed, which is typically an MS-DOS API call.== Real mode == When generating a software interrupt, the processor calls one of the 256 functions pointed to by the interrupt address table, which is located in the first 1024 bytes of memory while in real mode (See Interrupt vector). It is therefore entirely possible to use a far-call instruction to start the interrupt-function manually after pushing the flag register. One of the most useful DOS software interrupts was interrupt 0x21. By calling it with different parameters in the registers (mostly ah and al) you could access various IO operations, string output and more.〔(Definition of: int 21 )〕 Most Unix systems and derivatives do not use software interrupts, with the exception of interrupt 0x80, used to make system calls. This is accomplished by entering a 32-bit value corresponding to a kernel function into the EAX register of the processor and then executing INT 0x80. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「INT (x86 instruction)」の詳細全文を読む スポンサード リンク
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