Most Dr. Dudes are System 11C; only about 100 are WPC Alpha-numeric. The manufacturer referred to the VUKs on this game as ball poppers. Production Run Records for Dr. Dude And His Excellent Ray: Production Start Date: Aug-29-1990 Production End Date: Dec-19-1990 Production Run Quantity: approximately 3983, shipping quantity inexplicably 4002. First ship date: Aug-29-1990 Last ship date: Jan-9-1991