The K or Kitchen Computer

 The K- Computer

   Great discoveries and revolutions never occur in a vacuum. Numerous mathematicians and scientists, lesser known than George Boole and Claude Shannon, were also instrumental in developing the theoretical and technological basis for the digital revolution. George Stibitz was one such mathematician and early computer science pioneer.
   George Stibitz received a Bachelor of Science degree from Denison University in 1926 and his Ph. D. in mathematical physics from Cornell University in 1930. From 1930 to 1941 he was a research mathematician with the Bell Telephone Laboratories.
   At about the same time Claude Shannon was writing his master’s thesis on the application of Boolean algebra to electronic circuits, Stibitz gathered a conglomeration of old relays, batteries, flashlight bulbs, wires, and pieces of tin. Sitting at his kitchen table he tinkered an electromechanical circuit that added two binary numbers. 

   This was his famous Model K (for Kitchen) digital circuit that added two binary numbers. In computer science, such a device is called a half-adder. The K Computer would sum two binary numbers and produce a carry.

   I've simulated the K-Computer in Scratch. To view and/or download the project, see:

The K-Computer

https://scratch.mit.edu/projects/706747384/

   Relays were soon replaced by vacuum tubes and vacuum tubes by transistors. Transistors were hard-wired into chips and chips power the digit revolution we experience today. AND, OR, and NOT gates are the heart of all of our digital devices. I've simulated these and more in Scratch. Here's a list of my Scratch digital projects.

2 Half Adders = Full Adder
https://scratch.mit.edu/projects/652039462/

Half Adder
https://scratch.mit.edu/projects/244661995/

XOR Full Adder

https://scratch.mit.edu/projects/642224075/

Full Adder Using AND, OR, and NOT Logic Gates

https://scratch.mit.edu/projects/651492701/

XOR Gate
https://scratch.mit.edu/projects/3270654/

NAND Gate
https://scratch.mit.edu/projects/500283359/

NOT Gate

https://scratch.mit.edu/projects/706766377/

OR Gate
https://scratch.mit.edu/projects/706937270/

AND Gate
https://scratch.mit.edu/projects/706758161/