> An x86 monopoly in the late 80s was a thing, but not now.
Incorrect, we have an even greater lack of x86 vendors now than we did in the 80s. In the 80s you had Intel, and they licensed to AMD, Harris, NEC, TI, Chips & Technologies, and in the 90s we had IBM, Cyrix, VIA, National Semi, NexGen, and for a hot minute Transmeta. Even more smaller vendors.
Today making mass market x86 chips we have: Intel, AMD, and a handful of small embedded vendors selling designs from the Pentium days.
I believe what you meant was that x86 is not a monopoly thanks to other ISAs, but x86 itself is even more of a monopoly than ever.
I believe in the 80s all those vendors were making the same intel design in their own fab. I don't think any of them did the design on their own. In the 90s some of them had their own designs.
Some were straight second sources but they all had the license to do what NEC, AMD, and OKI did, which is alter the design and sell these variants. They all started doing that with the 8086. There were variants of the 8086, 8088, and 80186, I'm unaware of variants of the 80188, or 80286 although there were still multiple manufacturers, I had a Harris 286 at 20MHz myself. Then with the 386 there were more custom variants of the 386 and 486. In the Pentium days Intel wouldn't license the Pentium design, but there were compatible competitors as AMD also began 100% custom designs that were only ISA compatible and pin compatible with the K5 and K6 lines.
At what point do we call a tweak to an original design different enough to count it... K5 and K6 where clearly new designs. The others were mostly intel with some changes. I'm going to count the rest as minor tweaks and not worth counting otherwise - but this is a case where you can argue there the line is and so others need to decide where they stand (if they care)
The NEC V20/30 series were significant advances over their Intel equivalent (basically all the 186 features plus more in an 8086/8 compatible package).
C&T had some super-386 chips that apparently barely made it to market (38605DX), and the Cyrix 5x86 (most of a 6x86) is substantially different from the AMD one (which is just a 486 clock-quadrupled)
Incorrect, we have an even greater lack of x86 vendors now than we did in the 80s. In the 80s you had Intel, and they licensed to AMD, Harris, NEC, TI, Chips & Technologies, and in the 90s we had IBM, Cyrix, VIA, National Semi, NexGen, and for a hot minute Transmeta. Even more smaller vendors.
Today making mass market x86 chips we have: Intel, AMD, and a handful of small embedded vendors selling designs from the Pentium days.
I believe what you meant was that x86 is not a monopoly thanks to other ISAs, but x86 itself is even more of a monopoly than ever.