branch offices, the old RETAIN system was phased out, and RETAIN/370 was renamed to simply RETAIN. Search engine RETAIN/370 ran special applications designed for technical support center use. Its most powerful feature was a full-text search engine, enabling most text documents in the system to be retrieved by using boolean search requests, similar in concept to full-text search engines in use today on the Internet, such as Google or AltaVista, although limited only to searching for individual words, or combinations of words, without reference to word-adjacency. RETAIN/370 was the first IBM system deployed on a large scale that had such a capability. The search engine component of RETAIN is called IRIS, for Interpretive Retrieval Information System (not to be confused with other non-IBM software systems of that name... IBM never sold this search engine as a product, so there was no trademark issue). Mirrored database In the mid-1970s, a RETAIN was expanded to permit multiple copies of the database to be hosted on geographically distributed systems. RETAIN's custom-built Data Bank Manager, which served as the foundation for all RETAIN applications, and the IRIS search engine, was modified to support "mirroring" of file updates to take place automatically across the network, in a manner nearly invisible to the application programs, but which providing a high level of data integrity. After this change, RETAIN hosts were created in two US locations, two in Europe, two in South America, and two in Japan. Most applications were developed by IBM programmers in Raleigh, NC, (moved to Boulder, Colorado, in 1976) with some work being done in North Harbour, UK. Registered users of the system numbered in the thousands, in over 60 countries. Remote support At the time System/370 was announced, along with the corresponding RETAIN/370 system, IBM announced that the new family of computers would be equipped to permit remote diagnosis of hardware problems. Each System/370 installation of model 145 and above have a telecommunications adapter included capable of being used for remote support. The hardware diagnostic programs were written to allow control via a remote connection to applications on the RETAIN system that could be controlled by IBM specialists located at the IBM support center in Chicago, managed by Paul Rushton, and also including the original plant of manufacture of the CPU. This form of support was dubbed "Data Link / Hardware". The connection was made through a communications device called an IBM