3 ms·
> 3.5" floppies - 800K-1.44MB, small and slow. I feel like a lot of people in this thread are missing a crucial part of the historical context: ZIP files can
by cesarb 4y ago
> 3.5" floppies - 800K-1.44MB, small and slow.
I feel like a lot of people in this thread are missing a crucial part of the historical context:
ZIP files can be split. That is, a single ZIP file can span more than one floppy disk. The entry for each compressed file in the central directory, which is always on the last floppy disk, has a field which says in which disk the compressed file can be found. If you had a multi-disk ZIP file, and wanted to extract a single file from it, you inserted the last disk, pointed the unpacking software at it, and it would tell you which disk(s) to insert (in sequence) to extract that file.
A lot of the strange decisions of the ZIP file format make sense if you think about that use case: you have a directory full of files, which you want to compress into a set of floppy disks; and once you have that set of floppy disks, you want to extract a subset of the compressed files. You also want to be able to extract the undamaged files even when the last floppy disk (with the central directory) is damaged.