| From: Alvin Starr <alvin@netvel.net> | Or you could try this | https://archive.org/details/howtobuildaworkingdigitalcomputer_jun67 | They has this book in my high-school library and it sort of got me hooked. That book is pretty misleading. It produces a box with lights. And electric combinatorial circuits to do adding or subracting of 4-bit numbers (as far as I can tell). And switches for memory. You, the operator, must execute the program. And choose the memory locations. And load or store values. Etc. (In about 1963, I built very limited adder with similar technology. I even made the switches myself. Very crude. I kept asking adults "what is a computer?" because I didn't know if I'd built one. None of them had answers. How much easier this would have been if there had been the internet.)