The ICT/ICL 1900 Range: ICT (International Computers and Tabulators) on 28 September 1964 announced the 1900 Range of systems, giving great emphasis on program compatibility and portability between all models in the 1900 range (present and future) and modularity via the ICT Standard Interface (“Each 1900 system will grow with the customer’s needs by replacing individual modules as needed, without needing to replace the whole system”). The 1900 continued to be marketed for ten years, and kept competitive and technologically up to date by continuous development, enhancement and replacement of its hardware and software modules.