I have left a System Card in the slot of my TG-16 since I got the system back in 1991. It's not always the same system card, and sometimes it is a regular HuCard instead, but I can honestly say that my TurboGrafx has never gone more than 2 or 3 minutes at a time without some sort of card inserted. Works fine. Maybe that's because it knows better than to piss me off.