Emulators go down hill after cartridge systems generation. Even N64 has difficulty performing issue-free.Really we're at the point where most consoles before last-gen are really well emulated. Our hardware is so far advanced relative to the consoles and the emulation software is so mature its hard to go wrong. There's some exceptions (Dreamcast and Saturn come to mind) but most other consoles are almost completely emulated by any 'major' emu.
Emulators go down hill after cartridge systems generation. Even N64 has difficulty performing issue-free.