start by writing down the number of choices offered/the number of electrical-connections on one-side of the processor; so if you count just eight spiny-looking connections, down one long-side of a processor, it's kinda-like a mixer w/eight channels; if eight signals can pass-through that mixer, all heading for a crown-amp, there's how-many configurations possible, with only eight push-button/switches, that just one of those signals must negotiate; switch1 can be open[zero] or closed[one]; this is basic-binary, and shouldn't be a huge problem[two's]; two-possibles times the next-two/possibles = four combinations; six more times to go/in scientific notation, we write two, to the power of of eight[tiny metal tines on that processor; a 2 with a word processing program's superscript function adding that tiny 8 above the line]; if you have not made-like the constipated-mathematician,...  and worked-it-out with a pencil,...  the answer is 256; that means that one byte of data, can represent any symbol on your qwerty[including those 'hidden ones,' requiring ctrl- or alt-keys], any function of your numeric-keypad, some HTML-code, thrown-in for good measure, and still have room to report to Uncle-Daddy your GPS-coordinates; my training was on PC's; not personal computers, but programmable controllers[picture your breaker-box, filled with switches(varying in size, depending on the 'load'); the equipment used in factories are similar, in that the largest motors, are connected to large switches; these switches have two sets of wires coming in/going out; one is the big wires carrying the current that will go to that motor, when the switch is closed; the little wires carry only low-voltage signal, that operates the big switch, from some remote push-button[also low-voltage] or from a CPU, somewhere in the factory; conventional motor-controls, require the mounting of 'normally-open' or 'normally-closed' CONTACTORS