Do You Even x86?

摘要

When you're staring at the screen of your Macintosh, and you give it some input, what's going on in there? Like, what's really going on? Sure, we all think of some high-level things that happen, but I'd like to go down to a lower level. The CPU is where the work gets done, and understanding how it works helps you understand program execution, how to read stack traces, and more. Let's dig into the depths of how this all works. First, though, we'll look at a little history. The first Apple machines-the Apple I, Apple ][ and the original Macintoshes-were all based on MOS Technology CPUs. This was a popular choice at the time. In the late 1970s through the mid-1980s, the computing landscape was much wider. In addition to Apple, companies like Atari, Commodore, Tandy, Acorn and more were all vying for attention. Most of them based their machines on a MOS Technology CPU of some kind. The Apple I used a MOS 6502. The first Macintosh, the 128K, though, used a Motorola 68000 CPU. The 68000 series was to form the basis for all of the early Macintosh computers, moving through the 68020, 68030 and 68040.