Posts in the “Books” Category - page 3
Even though Programming the Z80 was not written for the TRS‑80, it was one of the more popular TRS‑80 programming books. I suspect that this book and TRS‑80 Assembly Language Programming by William Barden introduced more TRS‑80 programmers to assembly language than any others.
The Source was a three volume set containing the complete source code of TRSDOS 6.2 (which was the same as LS‑DOS 6.2). Each individual book cost $99, so total cost for a complete set was $297. Later on, these prices were heavily discounted.