As far as I know the only released platforms for OS/2
were the x86
 and the
 dead at birth OS/2 for PPC. I have never heard of it for any other
 platform.  I'd love to see a directory listing of this PDP-11
 version.  It
 is possible this may have been a version of NT which had some
 rudimentary
 OS/2 text mode support, but was not based on OS/2.  I recall that NT had
 support for x86, PPC, and Alpha CPUs, so it would not be hard to believe
 that microsoft might have toyed with porting it to a DEC platform.
 But I
 see no listing for NT for the PDP-11 on Wikipedia. 
 Weren't there also ports of OS/2 and NT for MIPS?  For NT, that one seems
 fairly well-known, but for OS/2 I'm positive it exisited too (at least in
 vaporware).
 
 
 There was never any publicly acknowledged versions of OS/2 beyond the
 x86 and PPC releases, and OS/2 for PCC was difficult if not impossible
 to actually acquire even when IBM officially released it.  The PPC