Can I ask a wee toolchain question? Are you building/debugging a NEX or a SNA? I'd like to use Z80n mnemonics (NEXTREG etc) in a SNA so it can be debugged, but sjasmplus won't do that 48 mode, conversely it won't SAVESNA in Next mode! I just wondered if you had a workaround (DEFB the Z80n opcodes?)