AMD started producing Intel-compatible processors even before X86, as in 1975 they produced a reverse-engineered and unlicensed clone of 8080. Doing something l

AMD started producing Intel-compatible processors even before X86, as in 1975 they produced a reverse-engineered and unlicensed clone of 8080. Doing something like that would be unthinkable today. Also, AMD became a licensee of Intel's architecture after IBM told Intel that they require at least 2 sources for the chips, an agreement that Intel tried to cancel for 80360. Back in those days these licensing agreements were more about copyright and trade-secrets rather than patents. And AMD had to license X86 from Intel because reverse-engineering was too time-consuming, not because they felt threatened. The patents arms race started around year 2000, when the bubble happened. And it's not like Intel and AMD don't have a long history of litigation. They do. Basically AMD had enough time to get big and innovate or buy valuable technology on its own. After AMD Athlon was released, the big and mighty Intel was in real jeopardy of being driven out of the market, as Athlons were not only cheaper, but better in every way (compared to its predecessor, the AMD K6, which was good and with extra goodies like 3D Now, but lacked a good coprocessor). Having to license AMD64 was probably a big embarrassment for Intel too, considering Intel was the one that tried to introduce a new architecture that was not backwards compatible with X86 and failed ... though it's interesting to think about the reasons why Intel tried a new and backwards incompatible processor and personally I think existing licensees of X86 had something to do with it. Of course, today AMD seems to have lost their touch. For instance I'm typing this on a Thinkpad with an Ivy Bridge processor, that I bought because of Intel HD, the only graphics card with which you have absolutely no problem under Linux, as Intel's drivers are open-source. I was expecting AMD to do things like this after they bought ATI, but unfortunately they didn't. Such a shame.