Calculator This led the way to the first credit-card-sized calculators, such as the Casio "Mini Card LC-78" of 1978, which could run for months of normal use on button cells. There were also improvements to the electronics inside the calculators. All of the logic functions of a calculator had been squeezed into the first "calculator on a chip" integrated circuits (ICs) in 1971, but this was leading edge technology of the time and yields were low and costs were high. Many calculators continued to use two or more ICs, especially the scientific and the programmable ones, into the late 1970s. The
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.