RichardC (tich.delete@this.pobox.com) on April 6, 2017 5:31 pm wrote:
> RichardC (tich.delete@this.pobox.com) on April 6, 2017 4:57 pm wrote:
>
> > x86/DOS, and maybe IBM 360/370. And those were all proprietary so you couldn't much
> > about them (though when the M68K came out I remember people speculating about whether
> > they could rewrite the microcode and turn it into a 370).
>
> Actually, I'm guilty of projecting more recent x86 ISA license issues back into the past.
> Intel *did* license the i386 ISA to various vendors, when that came out. AMD was a
> second source for the 8086 and 8088 (IBM required a second source for PC components).
> Then Intel decided to start pulling its weight:
>
> https://en.wikipedia.org/wiki/Advanced_Micro_Devices#IBM_PC_and_the_x86_architecture
>
> "In 1984 Intel, in order to shore up its advantage in the marketplace, internally decided to no longer cooperate
> with AMD in supplying product information, and delayed and eventually refused to convey the technical details
> of the Intel 80386 to AMD.[94] In 1987, AMD invoked arbitration over the issue, and Intel reacted by cancelling
> the 1982 technological-exchange agreement altogether.[95][96] After three years of testimony, AMD eventually
> won in arbitration in 1992, but Intel disputed this decision. Another long legal dispute followed, ending
> in 1994 when the Supreme Court of California sided with the arbitrator and AMD.[97][98]
>
> In 1990, Intel also countersued AMD, reneging on AMD's right to use derivatives of Intel's microcode
> for its cloned processors.[99] In the face of uncertainty during the legal dispute, AMD was forced
> to develop clean room designed versions of Intel code for its x386 and x486 processors, the former
> long after Intel had released its own x386 in 1985.[100] In March 1991, AMD released the Am386, its
> clone of the Intel 386 processor.[52] By October of the same year it had sold one million units"
>
> So any effort to build an x86-compatible cpu in the mid-1980s was going to face some
> pretty heavy lawyering and obstruction from Intel (though they later did license the
> 80386 ISA to various manufacturers).
>

That isn't remotely what I remember.

8086,8088 had a bunch of second sources (required by IBM to use 8088 in the PC).
80286 had a few sources
80386 had AMD and IBM.

Intel sued AMD claiming that licensing the "use" of Intel microcode didn't include re-selling and eventually won (this caused all sorts of issues for AMD and not-quite-cleanroom code).

IBM made a few chips, I think the last was the [IBM]486SLC [no relation to the early Cyrix chip of the same name], a chip that was almost certainly didn't make economic sense to design and manufacture.

Cyrix came along and laundered their IP by having IBM manufacture the chips. Thanks to Intel's relentless lawsuits (all of which Cyrix won), Cyrix was paying lawyers 9$ for each 1$ paid to engineering. Eventually they couldn't keep up with Intel.

No idea what license the IDT/Via winchip had, but it got killed by a price war between Intel and AMD (IDT was selling it as an alternative to producing SRAM).