Patent ID: 6535146
Filing Date: 2003-03-18
Classification: H03M

Abstract:
A method of detecting short-circuits of a keyboard, which is applicable to a computer system consisting of a keyboard, a keyboard controller, a computer mainframe with a buffer, a central processor unit and a memory device, and a display unit, the method comprising the following steps:(1) establishing a database of standard scanned codes and a keyboard matrix corresponding to keys of the keyboard in the computer mainframe; each key being assigned with a scanned code and a key number and the keyboard matrix being composed of rows of data lines and columns of data lines; (2) pre-defining a set of 25 keys for detection purpose; (3) using a predefined interrupt service procedure to obtain the scanned codes of computer keyboard; (4) pressing one of the predefined keys of the keyboard for the keyboard controller to receive a signal variation and to then produce a scanned code responding to the pressed key, followed by transmitting the scanned code into the buffer of the computer mainframe for the process of conducting comparison of the scanned codes; (5) having the computer mainframe to analyze and process the data in the buffer for comparing the scanned code obtained from step (4) with data in the database of standard scanned codes in the computer mainframe; (6) showing messages on a screen of the display unit for identifying the pressed key that is short-circuited and indicating data of the columns and rows of the data lines corresponding to the pressed key and the keys short-circuited with the pressed key; (7) performing the steps (4)-(6) until the 25 predefined keys have been respectively pressed and then moving to step (8); and (8) showing the complete short-circuit status of the keyboard on the screen of the display unit.