Note: The earliest IBM PCs used single-sided floppy drives and MS-DOS 1.0 does not support double-sided drives. Double-sided drives were introduced in the IBM PC in 1982 and are supported in MS-DOS 1.1. [https://minuszerodegrees.net/5150/early/5150_early.htm Source]
Fun fact: The original IBM PC didn’t have a hard drive, even as an option. But the floppy drive was not the only option to load programs on IBM PC. You could also use a tape deck, just like on Amstrad CPC. However, the tape port disappeared with the IBM PC/XT.[https://en.wikipedia.org/wiki/IBM_cassette_tape Source]
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