Abstract: Disclosed are a printed circuit board and a method for wiring signal lines on the same. Connecting lines for electrically connecting chip select pins of a semiconductor chip, no connect pins and address designate pins, are formed on a PCB. In case of an unstack type, a pad is connected to chip select pin and no connect functioning pin of other semiconductor chip via a first signal line. In case of a stack type, another pad used with a pad is connected to a no connect functioning pin and a chip select pin of the corresponding semiconductor chip having no connection with the first signal line via a second signal line. According to the type of semiconductor chip, e.g. unstack or stack type, a second connecting pad selectively connecting by a first jumper having almost zero resistance value, is disposed between the first and the second signal lines. A first connecting pad is also disposed at the second signal line, the first pad is selectively connected by a second jumper having zero resistance value.

Abstract: A key telephone system with a database dynamically sets a least cost route based on an access frequency distribution value of the database. For that purpose, the key telephone system evaluates access frequency distribution values of records in the database, indexes the records in order of the access frequency distribution value, and creates an index table. Then, the key telephone system searches the database based on the index table by a binary searching. The index table is a digit comparison table.