I've never "assembled by hand" but I can believe it and imagine it. As a kid I did write basic code by hand and would type it into my Timex Sinclair with no ability to save it because we could not get the tape cassette to work to save it. So for the first few weeks it would all disappear when you turned the computer off. What a blessing it was to get that cassette to work and be able to save and load our programs back! The next thrill was finally getting a disk drive for a later acquired Commodore 64 and ditching the tapes. Not only storage but random disk access what a concept.