What Operating System Is This?
Inside Macintosh Volumes I, II, III (PDF)
Here are all three volumes of the original 1985 edition of Inside Macintosh as a searchable PDF:
Reconstructing the Leftovers on the Amiga Kickstart 1.0 Disk
Update: The source is available at github.com/mist64/extract-adf; more info here.
64’er 04/1984 (PDF)
I converted the first issue of the German Commodore 64 magazine 64’er into a searchable PDF: