Old Typerwriters and Calculators

In this channel we will see many old typewriters, calculators, and old technologies in general.
But we will see also other office devices, mimeographs, radio, and old computers. 
Very often we will see how they work, and their history, how the typewriter developed from the end of nineteenth century. 
It's all based on the collection of my father, who collected these devices for half a century. So I have to thank him.