Changes

* Remove or disable the ROM in the disc-interface, and cut the ROMDIS signal in the disc-interface (so the built-in AMSDOS in the CPC+ is used instead of the external DOS; this can be done without EPROM burner, but doesn't support 80-track drives)

* Use an external DOS that resides elsewhere than in ROM bank 7 (whereas, the external DOS must undo hooks and memory allocations done by the internal AMSDOS; this should be supported by ParaDOS)