Direct Diagnostic of Keyboard Hardware on a Personal Computer
Original Publication Date: 1985-Jul-01
Included in the Prior Art Database: 2005-Feb-18
This article describes a technique to properly diagnose the various failure modes of a keyboard. The ability to isolate a failing device on a system is essential to provide the highest level of serviceability to the user. Each device must have diagnostics, and the system should have hooks to allow for future devices. A problem arises when the system cannot communicate to a device. An example of this is the serial input device called a "keyboard". To properly diagnose the various failure modes of a keyboard, it can have outboard diagnostics to test itself. Many keyboards contain a microprocessor that scans the keys for changes and outputs scan codes to the system. The microprocessor software can be enhanced to allow for diagnostics. Diagnostics are run during manufacturing test, power on and at user request.