<u>'''To clarify the graphic:</u>'''
You know the imported RSX commands from AMSDOS, like |DISC, |REN, |ERA and so on. Furthermore you know the BASIC statements to access disk or tape like OPENIN or LOAD, which actually calls CAS vectors. CAS vectors originally belong to cassette tape. AMSDOS alters all CAS vectors and fools the OS. SymDOS does the same with AMSDOS.