Casio
 

The Casio brand name is synonymous with the compact electronic handheld calculator. However their calculators were not always so small and portable. They began, back in 1958, with a computational device that was constructed from relays and diodes which weighed a colossal 120kg!

In 1960 they made the first 'scientific calculator' -  the 'Model 301', again very large and cumbersome. In the mid-60's they realised that they would have to change to making electronic calculators or perish. So, towards the end of the 60's they produced a number of desktop calculators with nixie tube displays. 

The following eight models are all examples of Casio's green fluorescent display models of the 70's. It is possible to attribute their success in the late 1970's to their consistent ability to pack more and more scientific functions into ever smaller units. Casio's budget low-powered LCD models of the early 80's became extremely popular with schoolchildren studying maths.