Commodore 64 Programmer's Reference Guide. Published by Commodore Business Machines, Inc., originally copyright 1982, this is a first edition of the 9th Printing from 1984. Spiral-bound trade paperback, 486 pages. Small crease in upper left back cover corner. There is a reference card in the back of the book that can be removed along a perforated edge and a foldout schematic diagram; in between the two is another perforated strip where something was removed.