On Wed, 2017-11-01 at 18:45 +0100, SFM wrote: > I didn’t create a partition table (at least not explicitly), all I know is, i > used a live MacOS X CD To create the HFS+ partitions
If you created partitions with Disk Utility, then you have a partition map. Did you install MacOS first? I believe install.macppc recommends that Mac OS be up and running before you run the OpenBSD installer.