Date: April 1, 1994 Page: 32 Section: BUSINESSA public ''test drive'' of virtual reality, a children's computer art contest and displays from more than 100 computer hardware and software dealers will be part of ''MegaMeeting,'' to be held April 9 and 10 at the University of Masschusetts' Harbor Campus. Organized by the Boston Computer Society, MegaMeeting will include activities and exhibits geared to both novice and experienced users, according to the society's Pam Bybell. Activities include a ComputFest, seminars on the effects of computers on society, and awards to recognize the best and worst in customer service. Admission is $7 for adults; children under 16 are free. For more information, call 290-5700. The fourth annual New England Computers and Social Change Conference will be held this weekend at UMass-Boston, as part of the Boston Computer Society MegaMeeting. The conference is a gathering for community activists, nonprofit staff, board and volunteers who use computers and telecommunications or plan to, and students, teachers and computer professionals who want to contribute to social change. This year's conference features a keynote address by Howard Rheingold, editor of the Whole Earth Review, via interactive video teleconference. Rheingold will address the emerging medium of the virtual community. A panel presentation by the Computer Professionals for Social Responsibility will discuss the question: "The Information Superhighway: What Is It? Why Do We Care?"