<P> While it is most common for the Fn key processing to happen directly in the keyboard micro-controller, offering no knowledge to the main computer of whether the Fn key was pressed, some manufacturers, like Lenovo, perform this mapping in BIOS running on the main CPU, allowing remapping the Fn key by modifying the BIOS interrupt handler; and Apple, in which the Fn key is mappable and serves other uses too, as triggering the Dictation function by pressing the Fn key twice . </P> <P> In addition to being mapped to standard keyboard keys like Scroll Lock and Num Lock, the Fn key combinations may also be mapped to control system interfaces to change the LCD brightness, VGA output, or speaker volume on most laptop computers . </P> <P> There is not yet an agreed - upon standard for the placement of the Fn key, although most manufacturers have elected to place it alongside a shrunken and / or displaced left Control key . Because the Control key is most frequently associated with OS and application shortcuts (such as Control + S to save a document, or Control + Shift + Escape to launch the Task Manager in modern versions of Microsoft Windows) altering its size and placement is often regarded as inconvenient for users accustomed to the larger left Control key on IBM PC - style keyboards commonly used for desktop computers . </P> <P> The majority of portable computer manufacturers today (including HP, Dell, and Samsung) currently place the Fn key between the left Control key and the left Windows key, making it the second key from the left on the bottom row of the keyboard . This usually means that the Control key is reduced in size, but allows it to remain in the lowest - left position on the keyboard . </P>

What does the fn key do on mac