 The result of a three-year collaboration between Sinclair Research, ICL and British Telecom, the OPD had the addition of a telephone handset at one end of the keyboard, and rudimentary Computer-Telephony Integration (CTI) software.This machine interested a number of high-profile business customers, including certain divisions of the former UK Customs and Excise Department, but its success was generally limited.In the late 1980s they were used in bingo halls to allow a country wide networked bingo game.