Pacific Bell Inc has been showing off the uses of Integrated Services Digital Networking, which it is evaluating during the first stage of a technology test that promises new telecommunications services for customers: the tests, being conducted with Lockheed Missiles & Space Co, include file sharing and transfer, personal computer-to-personal computer and personal computer-to-host communications, dial-up video security, IBM 3270 host access and wide area networking; Sunnyvale, California is the first site to become operational in the three-city technology test; the other cities are San Francisco and San Ramon, California where testing is scheduled to begin this spring.