What's the strangest invention you've ever seen? One of my favorites:
This transistor-based DIY "computer" performs addition and subtraction, making clever use of a rotary phone dial for input. The circuit itself only increments or decrements the binary value; the dial makes it convenient to enter in a number automatically. Multiplication or division are possible with repeated operations. It was described in the book Computers! From Sand Table to Electronic Brain (Vorwald and Clark, 1961).
This transistor-based DIY "computer" performs addition and subtraction, making clever use of a rotary phone dial for input. The circuit itself only increments or decrements the binary value; the dial makes it convenient to enter in a number automatically. Multiplication or division are possible with repeated operations. It was described in the book Computers! From Sand Table to Electronic Brain (Vorwald and Clark, 1961).