Read files from vintage DOS 3.3 .dsk
There are two utilities with source code here:

FID - &quot;File Developer&quot; for .DSK images of DOS 3.3 disks
FID is a file manipulation utility for DOS 3.3 disk images in .DSK format.

a2tools
a2tools is a utility similar to FID: it can do a &quot;CATALOG&quot;, &quot;DELETE&quot;, &quot;SAVE&quot; and &quot;LOAD&quot; on Apple II .DSK images.


a2tools seems at least compilable, but I don't have any .dsk files to test it with.