Programmer's key

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 MacOS-era Macintosh systems, which jumps to a machine code monitor. On most 68000 family 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.

Modern Mac hardware no longer includes the interrupt button, as the Mac OS X operating system has integrated debugging options. In addition, Mac OS X's protected memory blocks direct patching of system memory (in order to better secure the system).

See also

• Interrupt
• Context switch
• MacsBug