You have to write assembly code to get the most out of any computer, but getting the most out of a computer has become less necessary over time.<p>The Apple ][ was also open in the sense that it shipped with full schematics and an annotated listing of the ROM (<a href="https:&#x2F;&#x2F;archive.org&#x2F;details&#x2F;applerefjan78" rel="nofollow">https:&#x2F;&#x2F;archive.org&#x2F;details&#x2F;applerefjan78</a>)<p>Inside Macintosh had a high-level description of the hardware, explained the memory map and how to call OS calls, and had good descriptions of the various data structures, but didn&#x27;t go as far as including full schematics or a full listing. It also was a separate thing to buy, so most users wouldn&#x27;t have it.