Computer keyboard lock

Method and apparatus for disabling the operation of a computer keyboard with respect to depressed keys as they are observed by the computer's CPU. Entry into, and exit from, the keyboard disabled state is made via specific, simultaneous combinations of depressed keys. In one embodiment of the invention a new software routing (31) is added to the existing keyboard software (12) to recognize specific, simultaneous combinations of depressed keys and alternately inhibit or allow transmissions from the keyboard to the computer CPU in response to depressed keyboard keys. In an alternate embodiment an apparatus (100) is added between an existing keyboard and the computer to similarly recognize specific, simultaneous combinations of depressed keys via a lock detection function (111) which alternately inhibits or allows transmission of keyboard clock (122) and data (123) signals, thus preventing depressed keyboard keys from being recognized by the computer CPU.