The ICL 7500 series (7501, 7502, 7503, 7561, etc.) was a range of terminals and workstations, that were developed by ICL during the 1970s for their new range ICL 2900 Series mainframe computers. The colour scheme was compatible with the 2900. The term 7561 is a commonly used though loose term for the interactive video aspects of the 7502 series. The 7501 and 7502 systems were known as Modular Terminal Processors in marketing publications. 7501 and 7502 systems were built at Blackhorse Road, Letchworth (1/3 factory). The 7500 series was largely superseded by the ICL DRS series.