Despite the fact that it looks like a Paleolithic flashlight, the Williams Tube was actually the first working storage device for binary data--it was developed in 1946. By 1948, its inventors successfully operated a program via a computer called the Manchester Small-Scale Experimental Machine that store the results of a 17-line program that calculated the highest factor of 218 onto the cathode ray tube. It worked like this: dots were drawn onto the tube, which then became positively charged. The area surrounding the dots became negatively charged. The difference between the areas is called a charge well (an effect termed “secondary emission”), but the length of time that the different charges remained on the tube were inconsistent and unreliable. Williams Tubes had to be hand-tuned for nearly every use.