I remember, but not the way you do.

IBM OS/2 and the associated PS2 computers were built to get away from
Microsoft MS-DOS. When IBM bought the operating system, they allowed
Microsoft to market MS-Dos using the bones of PC-Dos to other vendors.
IBM thought their bios kept them safe. When the clones arrived with
legal bios roms, for several hundred dollars a pop less, IBM felt they
needed to do something. The result was PS2 computers with a
proprietary bus, and OS/2. Anyone who wanted to build a PS2
compatible computer, had to license the bus from IBM. Few ever did,
and PS2 failed.

As for IBM having to build the PC as an anti trust settlement, this is
the first I heard of it. When they started building the PC, we were
all worried that they would take over the market and we would be
forced to buy expensive IBM machines. If you have references or
documents showing this, I'd love to see it. A google search brought
up nothing along these lines, and there is no mention in Wikipedia,
nor does my own sometimes error prone memory, come up with anything.