The Computer Assisted Teaching Unit (CATU) was instituted at Queen Mary College in 1973 to provide aid to the Faculty of Engineering in developing and implementing computer-based learning procedures to support the undergraduate teaching program. Earlier computer programs had simulated electrical and nuclear systems to give students the opportunity to examine the characteristics and responses of these systems, and then, as now, were complementary to lecture, tutorial, and conventional laboratory work. By 1973, there were several computer-assisted instruction (CAI) programs in use, and a teaching station concept was implemented that combined a keyboard, a printer, and a screen. The need to establish a multi-user CAI system to accommodate increasing demand coincided with a national development program in computer assisted learning (NDPCAL) which provided some financial support for the system. Survival has been influenced by the concentration of CATU on CAI in engineering, which has made it difficult to obtain general college support and additional university support. However, after 10 years of operation, the CATU laboratory is now a well-established and integral part of the educational facilities. The collaborative development of CAI materials has produced an extensive library of packages which are available to the academic community through a program exchange. Twelve references are listed. (LMM)