Abstract: This paper presents the necessity to connect WWW with a database system, and describes how to implement this connection. It is also pointed out that the computer system based on the connection of WWW and database system, as a kind of implementation of system integration, is the future direction for the development of new generation software.Key words WWW,database,hypertext,system integrationClass number TP393;TP311.13 PPAGRSS A NEW SELECTION METHOD OF THE MODULUS SET OF PRNS DIGITAL FULL ADDER AND ITS IMPLEMENTATION ZHU Ming （Research Center for High Performance Computing, Institute of Computing Technology, Chinese Academy of Sciences,Beijing 100080） Abstract This paper strictly analyzes the selection of the modulus set, a key point in the new logic frame of the PRNS（positional residue number system） digital adder proposed by the author,and then gets an optimal set.The digital adder is finally realized with the current F100K ECL chips.