To some MSDOS was an major leap forward.
Personal Computer World magazine 1978 (Volume 1, Issue 1) published 'The Elegant Minmon' as a printed Z80 assembly code listing. After two years of soldering, typing it all in and adding a video driver (c/o Wieless World) it all sat in 1k bytes of Eprom.
By 1981 I would have killed for a floppy disk drive and any DOS (CPM?) to move beyond the tape cassette at 1200 baud, but I couldn't afford one - and/or feed the kids.
<grumble> Huh. People these days just don't know how lucky they are!!! </grumble>