This is "The Red Book". The Apple II Reference Manual. It's where the serious started their Apple II education. All the schematics, peeks, pokes and everything the novice needed to know about Apple II internals.
Other than slight yellowing on some of the pages, this one is in excellent condition. A special gem in any serious collector's display.
This item comes from the collection of a long-time Apple employee. Watch this space as more treasures are released.