IBM had made a concept PDA for which Hyperion made a version of OS 4.0 for. Shortly thereafter, IBM sold off the 440-series processor line to AMCC where it has gone on to become the processor in the SAM 440 series computers. I think, in order to get it to work on such a small form factor machine, they had to remove the 68k compatibility JIT, Petunia. Other than that it was not that much different from standard OS 4.
