NOP stands for (and is pronounced) no op, as in no operation. The NOP causes the processor to do absolutely nothing. What's it good for? Filling space. The 8080 can usually execute a bunch of NOP instructions without anything bad happening
Charles PetzoldThe human species is often amazingly inventive and industrious but at the same time profoundly lazy. It's very clear that we humans don't like to work. This aversion to work is so extreme - and our ingenuity so acute - that we're eager to devote countless hours designing and building devices that might shave a few minutes off our workday
Charles PetzoldOwning a computer without programming is like having a kitchen and using only the microwave oven
Charles Petzold