Longtime Apple fans love to praise the Apple II Red Book, the wonderful mashed-together collection of documentation that passed for an Apple II manual in the early days. The Red Book is beloved for good reason. It has a homey, chaotic vibe while also feeling like a found document of how the newest, most amazing technology really works. When I bought an Apple II in 1978, it came with a copy of the Red Book. That one was fun to read but frustratingly incomplete. Regular readers will not be surprised to know that I’ve kept my copy all these years. But never mind that book. Let’s talk about this one:
The Apple II needed a proper reference manual, and Chris Espinosa and Jef Raskin knew it. The Red Book was cool, but for my money ($20, Apple part number A2L0001A), the Apple II Reference Manual is an unsung masterpiece. Chris’s manual was a revelation. It’s a comprehensive, understandable, beautifully produced guide to Woz’s virtuoso creation. Wire-bound and over 200 pages, it’s chock full of explanatory text, diagrams, schematics, photos, source code listings, and Apple fun. I lost many a happy day inside that wonderful book. I’m mainly a software guy, so my favorite parts were the info about the monitor program and other great bits. The Mini-Assembler documentation introduced me to assembly language programming and taught me what machine language is, something every kid should know.
The hardware documentation was incredible, even though I lacked the background to fully understand it. Lots of things inside the Apple II baffled me. Careful study of the Reference Manual helped me figure them out. What the heck was SWEET-16? The manual told me that it’s an advanced virtual CPU, brilliantly implemented in software by Woz, inside the Apple II that you can play with. The manual explained that you could make some things happen, like clicking the speaker or changing the display from text to graphics, just by referencing certain magic memory addresses. That was crazy! And eventually I understood what was going on.
Chris Espinosa’s beautiful book was the gateway to understanding Woz’s genius invention.
A few years later, I got to know Chris at Apple and even spent some time working for him. He helped me start writing my first book. We’ve stayed friends ever since. And in February 2026, I finally got around to asking Chris to sign my copy of his book, only about 46 years after it was published. Now it’s an even more prized possession.
I think I need to lose a day inside the Apple II Reference Manual again soon.
You can read the Apple II Reference Manual here, or even buy a copy on eBay.
I used to spend hours ignoring the teacher in middle school reading the Apple ][ Reference Manual. For sure one of the greatest creations of the early personal computer era and I can easily credit it for most of my early programming education.
Memories .... thanks for posting this!