He never plays it, he just rubs it with a diaper.
Quantum is one of those arcade games like I, Robot and Timber. Everybody always talks about how "rare" it is, and how few of them were made. Because of this it is a very expensive game. But it isn't nearly as rare as people make it out to be. The stories say that there were only 500 copies of this game made. Stories like that usually underestimate the number a bit, and several people online own Quantum machines with serial numbers over 500, so there were at least a few more than that.
The problem with "rare" games like that is that everyone knows about them, so they are almost invariably totally restored, never played, and kept in their original condition by someone who has lots of money to spend on "rare" games. Right now there are 24 original dedicated Quantum machines registered at vaps.org. The vast majority of arcades games never get registered there. There are plenty of game owners who don't even use the internet at all, and not even all web-enabled game owners bother to register their games. So, multiply that number by ten to get an idea of how many Quantum machines there really are.
Now 240 copies of a game floating around might make it seem like it is a pretty rare game. But not really. I would venture to say that the vast majority of all arcade titles currently have fewer than 240 examples left. Sure there are a good 10,000 Ms. Pac-Man machines out there (at least), but how many examples of Thief, Shark JAWS, or even Frenzy are still around? Less than 240, I can tell you that. Plenty of other games vanish entirely, simply because no one is looking out for them. Go look around at different websites that show people's personal arcade game collections, and you will see the same 100 or so titles over and over again, Donkey Kong, Galaga, Frogger, Zaxxon, et cetera. Now do the same thing but look for River Patrol, Thief, Clay Pigeon, and Tropical Angel. Chances are good that you won't be finding them. The vast majority of the 2000 or so arcade games from the classic era are unbelievably rare, but no one talks about them, so no one even realizes it. So basically Quantum is just as "rare" as 90 percent of the games out there.
A totally new high-energy video experience from Atari!
The game itself has an interesting concept, similar to Qix. You have to encircle various particles using a trackball controller. The game had some seriously high-tech vector hardware and used a very powerful (for the time) 6 Mhz Motorola 68000 CPU on a 16-bit data bus. This was one of the only vector titles ever made that was capable of producing solid vectors.
The game came in the same cabinet as Space Duel and Gravitar, but it was not a conversion kit. It had totally different art, and was only available in full dedicated cabinet form. Like all vector games, Quantum is very problematic, and monitor failures are very common.
I would have to recommend not getting this one for your arcade game collection. This title usually sells for well over $2000. The people that own this title are generally the same people who own I, Robot, Major Havoc, and all the other "rare" games. This title simply isn't worth the cost of entry. Play it in MAME if you want to try it out.