> MorphOS specific programming does not require AmigaOS 3.1 system calls either.

I think it does. After all, MorphOS API is a superset of AmigaOS 3.1 API.

> these twenty year or older routines

Work on MorphOS started 18 years ago, so that's the age of the oldest routines inside MorphOS (unless we want to restart the debate about illegal use of original source code).