> For background to sibling comments - AS/400 aka "System i" was historically a separate line of processors, but is now POWER running a software translation layer.

The software translation layer has been a feature of the platform dating back to the System/38 days, and was specifically intended to allow the CPU architecture to change without breaking software compatibility.

IBM i also has the "PASE" layer, which is a binary compatibility layer for AIX. Those applications do not use the translation layer.