BASIC was pretty much the de facto language of the 80s home computer. Simple to learn, dog slow to run. To do anything really interesting with these little 8-bit beauties involved programming machine code. Instructions are inserted into the memory, byte by byte, then executed directly by the CPU. Whizzy fast. impossible to read.
Here we find a fine example of a machine-code listing from PCW. Take a good look at those long lists of numbers, and realise that getting a single one wrong means hours of debugging. Interestingly the author has included a rudimentary checksum for each line, which I presume would have made the process somewhat less painful – typing in listings was frequently a two person job, one to read out the list of numbers, the other to type them in. For pale and wan little boys, with no interest in fresh air and exercise, this was a perfect passtime.