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
Telsen Electric Company Ltd Telsen Electric Company Ltd Telsen Electric Company was a British electronics company formed in Birmingham in 1924 by Mr. A. Macnamara at 207 Aston Road. In 1930 they moved to 56 Miller Street and shortly after moved to their new factory at the corner of Philips Street and Thomas Street. Incorporated in 1933, the Telsen Electric Company Ltd were manufacturers of wireless broadcast receivers, components and construction kits. They had a cabinet making department turning out polished furniture into which wireless receivers were built, mainly from their own components. They were also buying Bakelite cases from Edwin Elliot in Birmingham.