The top bit of an 8-bit character, which is on in character values
128--255. Also called {high bit}, {alt bit}. Some terminals and
consoles (see {space-cadet keyboard}) have a META shift key. Others
(including, mirabile dictu, keyboards on IBM PC-class machines) have
an ALT key. See also {bucky bits}.
Historical note: although in modern usage shaped by a universe of
8-bit bytes the meta bit is invariably hex 80 (octal 0200), things
were different on earlier machines with 36-bit words and 9-bit bytes.
The MIT and Stanford keyboards (see {space-cadet keyboard}) generated
hex 100 (octal 400) from their meta keys.
[glossary]
[Reference(s) to this entry by made by: {alt bit}{double bucky}{dread high-bit disease}{high bit}{senior bit}{space-cadet keyboard}]