These were (and still are today) leased by larger corporations, academic and government establishments worldwide for loading the INSPEC database in-house. In 1970, the production of the database also enabled the launch of a customised SDI service which was quickly followed by the INSPEC Topics service in September 1970. This service was based on 22 selected standard profiles in four main areas: computer-aided design, gas lasers,electro-optics and electronic reliability. Both these services were output on 6" x 4" index cards!
By early 1971, INSPEC had expanded to a full-time staff of over 100, including 30 information scientists and 70 acquisitions, proofreading, computing and managerial staff. 1972 saw the development of INSPEC's Unified Classification. Before this, and during 1972, the three abstract journals had been prepared using separate sectional classifications. The new classification - the first version of the one used today - was created in parallel with the INSPEC Thesaurus which, when published in 1973, contained approximately 4,000 controlled terms, compared with 9,400 in 2008.
INSPEC first went online in the Spring of 1973 in the UK using the Cybernet timesharing network. The project was called RETROSPEC I and only 20,000 records in computing and control were loaded for searching. However, the whole database (600,000 records) was available for searching in September 1973 through Lockheed's DIALOG retrieval system. This was only available in the USA, initially via the Tymeshare network.
By the end of 1977, INSPEC was searchable on six online hosts - DIALOG, BRS, ESA-IRS, SDC (Orbit) CISTI (Canada Institute for Scientific and Technical Information) and FIZ Karlsruhe.
Key Abstracts (a series of monthly current awareness journals containing selected abstracts from prominent journals and conference proceedings, created from the database in broad subject areas) was launched in 1975. The first six titles (now 22) were: Power Transmission and Distribution, Industrial Power and Control Theory, Systems Theory, Communication Technology, Electronic Circuits, and Solid-State Devices.