Magic Brain: Last Gasp of the Mechanical Calculator

The Three Epochs of Strategy (Part II) - The Poverty of Strategy

Pinwheel Calculator- how it works!

the WEBB Adder (mechanical calculator)

Restoration: A 100 Year Old Adding Machine

Vintage 1960's Magic Brain Pocket Calculator W/Stylus, Made in

Mechanical Calculator The Marvel of Arithmetic Without Electronics

Show and Tell: The Curta Calculator

Magic Brain Calculator - How to Multiply

Vintage Magic Brain Mechanical Calculator Made in Japan with

Brunsviga 11S mechanical calculator

Technology Marches On - TV Tropes

dividing by zero on a vintage mechanical calculator (Facit ESA-0