Programmer's key: Difference between revisions

Revision as of 13:42, 6 October 2007

Revision as of 21:13, 5 July 2008

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[[Image:Macintosh Classic II Left Side Reset Interrupt Switch.jpg|thumb|250px|The interrupt button/programmer's key protruding from the air vent on the left hand side of an Apple [[Macintosh Classic II]] computer (left with a circle symbol)]]

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. The interrupt is of highest priority, allowing debugging of [[interrupt handler]]s. 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 hasonce supported this function. On Macintosh computers running the classicmost [[Mac68000 OSfamily]] based Macintosh computers, an interrupt request can also be sent by holding down the '''command''' key and striking the '''power''' key on the keyboard. This effect is also simulated by the 68000 environment of the [[Mac OS nanokernel]] on PowerPC machines and the [[Classic environment]].

==See also==