Z80 Assembly Language Subroutines Leventhal TRS-80 Commodore 128 Programming

1985 Programming the Commodore 64: Definitive Guide Assembly Language Raeto West

6809 Assembly Language Programming - Leventhal Tandy Color Computer 3 CoCo OS-9

6809 Assembly Language Programming & Interfacing Tandy Color Computer Coco 3 #2

1979 Intel 8080/8085 Assembly Language Programming - Altair 8800 IMSAI etc.

6809 Assembly Language Programming & Interfacing Tandy Color Computer Coco 3 OS9

CBM Commodore 64 Basic Programming Course - Dr Watson Book & Tape.