Jade Falcon wrote:I thought amd was the major player in x86 dev and Intel stole it from them. I recall reading that intel and amd worked together on x86 then split up or something.
Of course not. Intel was the leading microchip company since way back when. They started with the 4004, the first successful mass-produced microprocessor. Which then evolved into the 4040, 8080, 8085 and eventually the 8086, which was the first CPU of what we now know as the x86 family.
IBM decided to use the 8088, a budget version of the 16-bit 8086, on an 8-bit bus, for their original PC.
IBM however didn't want to have any supply issues, so they forced Intel to license the 8088 architecture to second-source manufacturers. AMD was one of these manufacturers.
With the 80286 for the IBM AT, AMD once again was a second-source manufacturer.
By the time the 386 came, IBM was no longer relevant in the PC world. There were tons of clone builders to sell their x86 CPUs to, so Intel no longer had to dance to IBM's tune. Hence, the 386 was never sub-licensed to any other manufacturers. This effectively kicked AMD and the other second-source manufacturers out of the x86 world. Up to now, they were happily freeloading on Intel's x86 designs and the success of IBM's PC.
So, AMD decided to just reverse-engineer the 386 and launch their own carbon-copy Am386 CPU. AMD thought they could spin the second-source license in a way that they had the rights to manufacture ANY Intel x86 CPU, even ones that Intel never supplied the designs for, but which they reverse-engineered.
AMD was found guilty of copyright-infringement on the 386 microcode.
However, the court also decided, in a form of anti-trust, that x86 had become so relevant to the PC world, that it would be bad to have only a single manufacturer with a monopoly on the x86. So they forced Intel to license the x86 to others. Which led to the x86 cross-license deal with AMD and a few other manufacturers.
So AMD basically got away with reverse-engineering the 386 (and by then also the 486) and copying the microcode.
Having an x86 license is invaluable. Nearly every other CPU manufacturer became extinct, only x86 and ARM are still relevant today. AMD would be nowhere near the size they are today, if they even survived at all, if it wasn't for that x86 license.
Note also that especially in those days, it was very unusual to license CPU architectures to other companies (especially direct competitors). It was common for every CPU manufacturer to have their own proprietary CPU architecture and ecosystem.
These days it's somewhat more common... but still, could you imagine nVidia having to license AMD to be able to make Pascal-based GPUs, or AMD having to license nVidia to make GCN-based GPUs? Because that's what we're talking about here. We're not just talking about generic patents related to microchip design and manufacturing, we're talking about the actual instructionset, which allows AMD to run all software originally written for Intel CPUs, with 100% compatibility. That would be like being able to run nVidia's GeForce drivers on your AMD GPU, and getting all their game optimizations etc for free.