Jump to content

Photo

QBert - Infinite Points


16 replies to this topic

#1 mckafka99 ONLINE  

mckafka99

    Stargunner

  • 1,070 posts

Posted Wed Feb 28, 2018 7:16 PM

Looks like computer AI has found a couple of bugs in Qbert, one which appears to trigger endless point accumulation:

 

https://www.theverge...acked-bug-cheat



#2 Kosmic Stardust OFFLINE  

Kosmic Stardust

    Princess Rescuer

  • 17,327 posts
  • Location:Milky Way Galaxy

Posted Wed Feb 28, 2018 7:26 PM

a computer algorythm has found exploitable code in a computer game? oh, the irony!

#3 jaybird3rd ONLINE  

jaybird3rd

    Quadrunner

  • 8,850 posts
  • "Excuse me, sir? I have a question ..."
  • Location:806.4616.0110

Posted Wed Feb 28, 2018 7:42 PM

Posted earlier in this thread, but probably more likely to get noticed by 2600 players here.  I'd love to see if a human player can reproduce this on a real 2600:
 


 

I'd need to read the paper by the discoverers of this exploit, but judging from the video, it almost looks as if it was stumbled upon by accident rather than through some sophisticated analysis by the AI.



#4 R.Cade ONLINE  

R.Cade

    Stargunner

  • 1,186 posts
  • Location:Augusta, Georgia, USA

Posted Wed Feb 28, 2018 7:53 PM

I tried moving after completing the level and I can't do it... I wonder if it's an emulator bug in the system they are using?



#5 Supergun ONLINE  

Supergun

    Dragonstomper

  • 910 posts
  • Location:Orlando, Florida

Posted Wed Feb 28, 2018 9:07 PM

I played the hell out of 2600 Q*bert back in the day. It's still one of my favorite ports on the 2600. And I never found or had that bug ever happen to me.

But another 2600 Parker Brothers game gives you the ability to 999 your score through a glitch / bug in the game, so it is possible. (Montezuma's Revenge treasure room)

#6 CapitanClassic OFFLINE  

CapitanClassic

    Dragonstomper

  • 558 posts

Posted Wed Feb 28, 2018 10:16 PM

It might be the case that this bug of being able to move after the level ends only happens while moving up/down or left/right simultaneously.

#7 carlsson OFFLINE  

carlsson

    Metagalactic Mule

  • 7,101 posts
  • Location:Västerås, Sweden

Posted Thu Mar 1, 2018 2:57 AM

Perhaps the fact the AI is on the last life has any relevance, if it screws up some memory location when you complete the first level on your last life, perhaps in combination with moving in a certain direction.



#8 R.Cade ONLINE  

R.Cade

    Stargunner

  • 1,186 posts
  • Location:Augusta, Georgia, USA

Posted Thu Mar 1, 2018 6:58 AM

OK, I will try again tonight. I'm sure someone will find it before then...



#9 Atarian7 OFFLINE  

Atarian7

    River Patroller

  • 3,421 posts
  • Location:Maryland

Posted Thu Mar 1, 2018 7:13 AM

I can get infinite points on q*bert by passing coily or the other enemies in mid-air.



#10 FujiSkunk OFFLINE  

FujiSkunk

    Quadrunner

  • 7,535 posts
  • Behold the Fuji!
  • Location:Planet Houston

Posted Thu Mar 1, 2018 9:55 PM

I played the hell out of 2600 Q*bert back in the day. It's still one of my favorite ports on the 2600. And I never found or had that bug ever happen to me.

 

I did.  I never could get it to happen consistently, but it happened often enough that I knew it was a bug in the game and not some other random hardware glitch.

 

While I don't think it has anything to do with the number of lives (I could be wrong), I know it does have something to do with playing with the joystick while the end-of-level bonus is in progress, and I'm pretty sure Coily has to be on the board at the end of the level (he always was when it triggered for me).  Often I would tug on the joystick so that I could get moving immediately when the next level started, before enemies started appearing.  Sometimes instead I would end up suiciding off the bottom of the platform, and then the starting color for the next level would be radically different.  I can say for certain now that it's the same bug.  It always caught me by surprise that I'd end up dying before I could exploit it.  In fact I don't think I ever noticed that I was getting extra bonus points while the glitch was in progress.

 

While I don't know for certain how to trigger this bug, I do know of two other exploits that can get you infinite points on the first level, if you're that bored.  They both involve luring Coily up to the top cube.  If you can get Coily to jump on the top cube and then you jump down left and right to the bottom of the pyramid, always hopping across the "gap" that splits the pyramid more or less in half, Coily for some reason just might commit suicide instead of chasing after you.  This isn't a guarantee, but give each Coily enough chances and eventually he'll take the plunge.  Alternatively, if you can get Coily to jump onto the top platform at the same time you're jumping up and to the left right (edit: still can't get my directions right sometimes) off of the platform, you will "die", but Coily will still jump after you and your death won't count against you.  This one does work every time, so you can rack up your score faster with this exploit than the first one.



#11 glazball OFFLINE  

glazball

    Moonsweeper

  • 489 posts
  • Location:Austin, TX

Posted Fri Mar 2, 2018 8:43 AM

According to this BBC article that I read yesterday, the researchers "used an updated version of the game" - whatever the hell that means!



#12 nanochess ONLINE  

nanochess

    Processorus Polyglotus

  • 5,424 posts
  • Coding something good
  • Location:Mexico City

Posted Fri Mar 2, 2018 9:24 AM

The "gym" suite is impressive https://gym.openai.com/envs/#atari

I gave a look to the Github but for the Atari emulator I could only find the suite with Atari ROM set, but not a clear reference to the emulator.

Well, my abilities in Python are of apprentice :P

#13 stephena OFFLINE  

stephena

    River Patroller

  • 3,195 posts
  • Stella maintainer
  • Location:Newfoundland, Canada

Posted Mon Mar 5, 2018 8:08 AM

It's an old version of Stella, whatever was used in the "Arcade Learning Environment" (ALE).  Something like a 3.x version, I believe.



#14 gsampson35 OFFLINE  

gsampson35

    Space Invader

  • 15 posts

Posted Tue Mar 27, 2018 6:15 PM

OK, I will try again tonight. I'm sure someone will find it before then...

 

It's been found. 



#15 George Phillips ONLINE  

George Phillips

    Space Invader

  • 35 posts

Posted Mon Apr 2, 2018 1:56 AM

 

It's been found. 

 

Do you have any details on the bug?



#16 gsampson35 OFFLINE  

gsampson35

    Space Invader

  • 15 posts

Posted Mon Apr 2, 2018 4:50 AM

I have a video on YouTube showing me doing it on my console. There really isnt much to it. After you follow the pattern that the ai found. Then when the level ends to pause for a split second then move. Movement is limited to the bottom 2 rows. Thats the trick. Just search Qbert glitch on YouTube and you should see my video.

#17 George Phillips ONLINE  

George Phillips

    Space Invader

  • 35 posts

Posted Mon Apr 2, 2018 1:30 PM

Thanks.  Should be quite helpful if anyone wants to dive into the 6502 code and figure out the underlying bug.

 

A link to the video right before the bug is triggered:  https://www.youtube....GyeUuysyqg&t=86






0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users