When you mention, Osborne computer books, and 1980s I think of these (different ) books

Osborne Introduction to microcomputers, Volume 0 https://archive.org/details/an-introduction-to-microcomputer...

Osborne Introduction to microcomputers, Volume 1 https://www.rsp-italy.it/IT/Books/_contents/Osborne-An%20Int...

There is volume 2 in the series 2, too

I have originals of these books and his books on 6800 6502, 6809 and 68000 programming.