Ok, this post is not about tapes, it's about books.
But if you want to know everything about (old school) hip hop,
then i maybe have a great source for you.
Google books contains, as some of you may know,
many books and other publications.
It has both search and preview options.
One feature is IMO very exiting: you can filter
your search results and f.e. only look for "full view only".
You can even choose for filtering on a combination
of "full view only" and 'books'.
Even when you look at books with
limited preview options,
you still can read lots of
interesting pages and look at many, many great photo's.
For those who don't know Google Books
and/or are not familiar with
advanced search options,
I made some example queries.
Free viewable publications
about hip hop that where published in the 80's:
the book 'Graffiti' By Sandrine Pereira (free viewable!):
books with 'hip hop'
in the title that can be previewed here
Old School Hip Hop tapes