“The The Ultimate Commodore 1541 Disk Drive Talk” by Michael Steil, video from VCF West 2021:
(Topics: history, recording format, data transmission, fast loaders, non-standard formats, copy protection, preservation.)
See also,
https://www.pagetable.com/?p=1595
Related HN discussion: https://news.ycombinator.com/item?id=28553600