Calculator for example, solve quadratic equations symbolically. The first graphing calculator was the Casio fx-7000G released in 1985. The two leading manufacturers, HP and TI, released increasingly feature-laden calculators during the 1980s and 1990s. At the turn of the millennium, the line between a graphing calculator and a handheld computer was not always clear, as some very advanced calculators such as the TI-89, the Voyage 200 and HP-49G could differentiate and integrate functions, solve differential equations, run word processing and PIM software, and connect by wire or IR to other calculators/computers. The HP 12c financial calculator is still produced. It was
North Eastern Electric Supply Company World at the time. After the First World War it took over the Cleveland and Durham Electric Power Company, the Northern Counties Electricity Supply Company, Durham County Electric Power Company, and Tees Power Station Company. It also took over the assets of the Durham Collieries Electric Power Company and the Hexham & District Supply Company following their liquidations. NESCo opened North Tees Power Station in 1921 and Dunston B Power Station in 1933. In 1927, the company moved into their new headquarters at Carliol House in Newcastle's city centre. The building was designed by Robert Burns Dick. Carliol House Ltd.