> Before ARM the m68k was possibly the most deployed processor architecture in history

My money would be on something smaller such as the 8051 (https://en.wikipedia.org/wiki/Intel_MCS-51)

Also, between m68k and ARM there was PowerPC. It got used a lot in embedded systems. Because “the newer the car, the more microprocessors it has”, chances are it got used more than m68k.

FWIW, Google’s AI gives me:

- for the m68k: “industry analysis and historical data indicate that hundreds of millions of units were produced across the architecture's lifespan”

- for PowerPC: “By 2008, Freescale Semiconductor had already shipped over 100 million Power Architecture-based MCUs for automotive powertrain management alone. Hundreds of millions more have since been produced for networking, industrial automation, and aerospace applications.”

- for the 8051: “according to industry accounts and semiconductor historians, the cumulative production of 8051-based microcontrollers is estimated to be on the order of billions to tens of billions of units”

> My money would be on something smaller such as the 8051 (https://en.wikipedia.org/wiki/Intel_MCS-51)

Also MIPS. It was VERY popular in embedded. Also Sony’s PS1 and PS2.

Western Design Centre also claims over 6 billion 6502 compatible cores:

https://www.westerndesigncenter.com/wdc/about_us.php

Yeah, 8051 wins, it was and still is in everything (sdcards, sim cards, cables, ports...). I may have some trauma from spending too much time with Keil's 8051 C compiler that made me forget it.

But I still think 68k was king of that era for discrete CPU's that could go anywhere, and run a high level OS/complex software, before the MCU and then SoC era came and stole m68k's crown.

Sure, PPC took the m68k's role of discrete CPU in automotive, aerospace, networking and consoles for a while, but I don't think it is the king.

Back to TFA, I think the m68k got a bit more than just "commercial traction"! Which is why it will hopefully stay in the kernel for a long time.