The '''Programmer's Key''', or ''interrupt button'', is a button or switch on a [[computer]] which causes an [[asynchronous]] [[interrupt]] request (IRQ) to be sent to the [[central processing unit|processor]]. If a [[debugger]] is installed on the machine, it is activated when the interrupt request is processed, allowing the user to view and usually modify the computer's internal memory. This is quite useful in [[debugging]] software, which is why it gets its name.
The "key" need not always be a button or a switch. On some computers, it is a pinhole into which a straightened paperclip must be inserted (to prevent accidental activation).
This term is used chiefly among [[Apple Macintosh|Macintosh]] programmers, perhaps because the Mac hardware always has supported this function. On Macintosh computers running the classic [[Mac OS]], an interrupt request can also be sent by holding down the '''command''' key and striking the '''power''' key on the keyboard.
