Apple Chip Architecture from 1977 to 2026
The full silicon story: from Apple I to M5 (and beyond!)
This is a dual-purpose post.
On the face of it, I’m covering the various chip architectures employed by Apple over the last 50 years, colouring in the technical considerations and the business context.
But, much like I mix my cats’ worm treatment into their food, I am sneakily grinding healthy chunks of learning into the prose: each chapter serves as a framing device for fundamental CPU concepts, growing in complexity. If Android is more your cup of tea, just jump between chapters at will like an overclocked instruction pointer.
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Contents
Click any of these to skip the intros and start learning.
1977: 6502 Microprocessor and the Apple I & ][
1984: Motorola 68k and the Macintosh
2006: Intel x86 and the MacBook
2020: Apple Silicon and disruptively good laptops
Apple’s core counter-positioning has been firm from their founding all the way to becoming a $4T megacorp: tight integration of hardware and software. This gives them pricing power that OS players (Microsoft, Google) or hardware manufacturers (HP, Dell, Samsung) only dream of.
Maintaining this integration gives them a durable competitive advantage. It allows them to make products that “just work”, and also gives them full control over the ecosystem (ask Meta if that matters).
This control is what allows them to casually migrate their entire chip architecture. They’ve done it three times! There’s often skepticism regarding CPU architecture migrations. Devs get tetchy about you deprecating all their software at once.
With 2005’s move to Intel x86, some commentators even guessed it was a precursor to bringing Apple onto Windows. The horror. But, ultimately, Apple has their reasons: short-term pain for strategic gain. Each new CPU architecture helped Apple compete and differentiate.
Today’s odyssey goes through the 5 key eras of Apple CPU architecture. 1977 up to 2026. I’ll colour in the business context surrounding each migration and bring you forward through the results of each shift.
Along the way, we’ll learn the basics of CPU technology; learning increasingly complex chip design techniques along the relentless learning curve of technological advancement.
This post is full of knowledge, so much so that your email client might cut it off. Read on my website for the best experience.
1977
Chip Family: 6502 microprocessor
Tech it unlocked: The Apple I and Apple ][
1 smelly hippy. 1 big bushy beard. It can only be the 2 Steves.
The Apple I in 1976 launched the company. If you can dust off one of the 200 units ever produced, you’re in luck as it’s the most valuable personal computer in the world (think Ferrari money).
The Apple ][ (pronounced “Apple Two”) was their first smash hit, so good they milked it for 16 years. It truly helped revolutionise the personal computing, uh, revolution.
In the mid-70s, hobbyists orbited a few popular microprocessors like the Intel 8080 and the Motorola 6800. The instruction set architectures of these chip families were the closest thing the nascent world of hobby computing had to an ecosystem.
A few Motorola engineers defected to MOS Technology to build the 6502, which was similar enough to 6800 for Woz to be familiar with it (maybe too similar: MOS flew too close to the sun with the 6501 and got sued for IP theft).
The Intel 8080 and the Motorola 6800 both cost more than $150, which is approximately a fucktillion in 2026 dollars. Therefore the choice of 6502 was not so much strategic and more because it cost $25, and Woz’s stock options had not yet appreciated that much.
He was able to cheaply acquire a bunch of 6502s, cobble together some computers, and write a BASIC interpreter.
BASIC was the “vibe coding” of the day. Hardcore, gruff, staff-engineer archetypes have always looked down on people not doing “proper programming” (6502 assembly) and relying on words instead.
Woz aptly performed the 3 core activities of early computer manufacturers: choosing an off-the-shelf processor, designing hardware around it, and providing a friendly programming environment. These form the foundation of the integration between hardware and software maintained by Apple today.
The Apple I was a neat machine that counter-positioned against the do-it-yourself “kits” popular in the day: a pre-built, quality-tested, plug-and-play board introducing the “it just works” philosophy.
The Apple ][ took this baseline and created a killer consumer product with colour graphics, sound, a plastic case, expansion slots, and BASIC in its read-only memory.
Both used the 6502.
The 6502 was an 8-bit CPU running at 1.023 MHz, with a 64KB memory address space: just a hair more powerful than today’s RyanAir mobile app.
OK: numbers, acronyms, words, blah blah blah. Let’s get on the same page.
The CPU™
A CPU, or central processing unit, is a device that moves data from computer memory (RAM) into fast temporary memory (registers), runs operations on this data, and then moves the output back into memory.
A control unit takes a feed of instructions, decoding them one-at-a-time, to decide what data moves to which register, and which register’s data should be piped through which logic circuits.
Fundamentally, all software behaves by arranging inputs into the CPU and handling the outputs. Databases. Operating systems. Intelligent refrigerators.
Registers
A register is a tiny speck of storage hardware. When I say “electronic memory,” I mean a circuit which, while powered, is able to hold onto its current value: on or off, 1 or 0. The smaller you can get this circuit, the more data you can store.
This is also, more or less, how RAM works (except there’s a lot more of it).
Registers hold a tiny number of bits very close to the CPU processing circuits. They are small, and close, making them really fast, operating at the MHz (or later, GHz) levels of the fully-clocked CPU.
The ALU
The last key piece of circuitry to understand is the Arithmetic-Logic Unit (ALU), the aforementioned “logic circuits” that actually perform these operations. The ALU is fundamentally a collection of circuits that perform simple, specialised jobs, such as:
Adding up binary numbers, e.g.
0010+0101=0111Perform logical operations, e.g.
NOT0000=1111Shift bits around, e.g. left-shifting
0011by 1 place becomes0110
The CPU executes instructions to perform operations on the data in registers, manipulating 1s and 0s which, by the magic of boolean algebra, emerge into useful outputs such as matrix multiplication, collision physics in a video game, or rasterising image data into on-screen pixels.
If this section has afflicted you with FOMO, someone built an Apple ][ emulator in JavaScript.
1984
Chip family: Motorola 68k
Tech unlocked: The Macintosh.
1981.
Reagan. MTV. Indiana Jones.
The Apple ][ is a cashflow geyser, but there are barbarians at the gates.
IBM has finally penetrated the PC mass market, precipitating an unprecedented influx of purchase orders for PCs. A young, brash, 24-year-old whizkid named Bill Gates was asked to supply their operating system.
In 10 years, let’s check in on our friends at IBM to see how this move went.
Apple needed a new platform upon which to build their future. Apple’s Lisa is shaping up to be their flagship product. After being a huge jerk to everybody for 5 years, Steve Jobs has been relegated to run the low-end Macintosh project.
Choosing a CPU
Originally planned as a lower-price-tier computer, the Macintosh under Jobs pivoted to focus on one thing: upstaging the Lisa team. Steve got some “inspiration” from his friends at Xerox PARC to bring a cutting-edge GUI to the Macintosh, and demanded advanced hardware to support it.
Understanding how a CPU works doesn’t come up every day, but for a lot of software engineers it’s assumed knowledge you have to pick up someday.
Apple’s story over 5 decades is also interesting reading. Read ahead for the full set of 3 chip architecture migrations, from Motorola 68k, to PowerPC, to Intel x86, ultimately to Apple Silicon.
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