MESS generally supports two keyboard mode command line options: '''emulated''' (the default; based on key position) and '''natural''' (command line option "-natural"; based on the character generated by a key, e.g. pressing "z" will always generate a "z" on the emulated system, even if the keyboard positions are different). In emulated mode, keys can also be remapped in the menu: press ''Tab'', then select ''Input (this system)''.
==ROMSROMs==
Just as in MAME, some MESS ROMs have parent ROMs that also need to be installed. E.g., <tt>cpc6128.zip</tt> also requires <tt>cpc464.zip</tt> to run.