digital computer

digital computer

To the person who said Babbage invented a mechanical calculator: Take a look at the analytical engine - it has ALL of the functions of a modern digital computer. It was capable under program control of adding, subtracting 50 DIGIT numbers (about 60 a minute) as well as multiplying 2 50 digit numbers and producing a 100 digit product.The machine has three cogwheels. The operator places the left wheel at state 6, the middle wheel at state 9 and the right wheel at state 4 (this corresponds to the upper diagonal in the table above). At the first half cycle, a clutch (like the one in your car) joins the left and middle wheels. The machine turns the middle wheel to zero position, that is, 9 steps clockwise, moving the left wheel 9 steps counterclockwise - bringing the left wheel to state 15. At this point, the clutch is drawn back and a spring returns the middle wheel back to its original position - state 9. At the next half cycle, the clutch joins the middle and right wheels. The machine turns the right wheel 4 steps clockwise, moving the middle wheel 4 steps counterclockwise to position 13. A spring now returns the right wheel to its original position - state 4.