Editing Alt key (section)

==Evolution==
The Alt key has come to replace the [[Meta key]] of the old MIT keyboards. In their original function, both Alt and Meta would set the high [[bit]] of the signal generated by the key to 1 (for example, A generates 01000001 while {{key press|Alt|A}} generates 11000001). However, in modern software, due to the requirement for all bits to be used for post-ASCII 8-bit character sets, Alt no longer works in such a way.

[[File:AppleAlt.jpg|thumb|right|The Alt key on an Apple keyboard]]

Since the 1990s, Alt has been printed on the [[Option key]] ({{key top|Opt}}) on most Mac keyboards. As of 2017, the newest Apple keyboards do not contain the Alt label. Alt is used in non-Mac software, such as non-macOS Unix and Windows programs, but in macOS it is always referred to as the Option key. The Option key's behaviour in macOS differs slightly from that of the Windows Alt key (it is used as a modifier rather than to access pull-down menus, for example).