jPV schrieb:

Just to make it clear:

The MOSSYS: assign points to the SYS:MorphOS/ directory, and SYS: points to the system boot partition, which is by default named as System:, so MOSSYS: usually points to the System:MorphOS/ directory :)

The whole SYS:MorphOS directory is replaced in an operating system upgrade, so any modifications you make there is lost at the upgrade, so better not to copy or modify anything there. But with one exception, the installer knows to keep the MOSSYS:Libs/rexxsyslib.library_disabled file named like that and doesn't bring a new dummy rexxsyslib.library file into the system.

If you copy a 68k version of the rexxsyslib.library file into the SYS:Libs/ directory, it will be loaded from there if the original dummy file is renamed as _disabled in the MOSSYS:. Files in the SYS:Libs/ are preserved in a system upgrade, so everything works as supposed after the upgrade. If you'd have copied the library into MOSSYS:Libs/, it would be needed to copy it again after each upgrade.