Legality depends on the country or even specific region of a country you live in.
As for moral reason, I would say it would be moral so long as you own the game and the console. I would even go as far as to say, if you do not own the game for the particular console (but you still own the console) but own a legitimate version of it that is being emulated on another system (for example, you have a Sega Genesis console but you do not own Sonic for the Genesis but instead you own the Virtual Console version which is a direct emulation of the Sega Genesis version) then that would also be moral. The only cases where I would say it is immoral is if you do not own the original game, the console that is being emulated, or you do own the original and are emulating a modified new release that you do not own (like a remake).







