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The Official 2600 Easter Egg and Programming Mysteries Thread


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#26 e1will OFFLINE  

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Posted Mon Sep 27, 2010 12:53 PM

Cool. I've always wondered about that. How curious that it should be part and parcel of having to reposition a sprite. Maybe it's a timing thing (i.e. it's not "caught" before each screen update)?


It's definitely timing related. STA HMOVE is the actual command that causes the black line to appear, and there are reams of info and discussion to be found about how it works and how to get it to do neat tricks. Ed Fries recently talked about it a little bit here, which is probably a decent introduction.

--Will

#27 A.J. Franzman OFFLINE  

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Posted Mon Sep 27, 2010 3:10 PM

(deleted by poster)

Edited by A.J. Franzman, Mon Sep 27, 2010 3:17 PM.


#28 A.J. Franzman OFFLINE  

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Posted Mon Sep 27, 2010 3:12 PM

Cool. I've always wondered about that. How curious that it should be part and parcel of having to reposition a sprite. Maybe it's a timing thing (i.e. it's not "caught" before each screen update)?

I think it's a bug in the design of the TIA chip which was never corrected.

#29 Chris++ OFFLINE  

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Posted Mon Sep 27, 2010 4:42 PM

Awesome. Thanks for the info. This will be a great thread to search someday for answers about odd 2600 idiosyncrasies and curiosities, especially if I stop posting barely related replies like this one.

#30 Ranthulfr OFFLINE  

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Posted Sat Nov 20, 2010 12:00 PM

Okay, here is a question that's been bugging me for a while. It is a question of MONUMENTAL IMPORTANCE. As far as I can tell, all of the open passages in the Montezuma's Revenge layout are accounted for. In other words, they all lead to a known room. Except for one. The passage on the right side of this room (see pic) may not be truly accessible, because Panama Joe can't jump that far. Still, it must go somewhere, right? Is it a shortcut to the treasure chamber? Does it lead to the inner workings of the game program, causing it to crash? Where does it go?

Attached Thumbnails

  • Mon_Rev.JPG


#31 A.J. Franzman OFFLINE  

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Posted Sun Nov 21, 2010 2:23 AM

As far as I can tell, all of the open passages in the Montezuma's Revenge layout are accounted for. In other words, they all lead to a known room. Except for one. The passage on the right side of this room (see pic) may not be truly accessible, because Panama Joe can't jump that far. Still, it must go somewhere, right? Is it a shortcut to the treasure chamber? Does it lead to the inner workings of the game program, causing it to crash? Where does it go?

Warning for those who haven't solved the game, and want to map it out on their own, there be spoilers ahead!

Spoiler


#32 Deteacher OFFLINE  

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Posted Mon Nov 22, 2010 4:27 PM

My guess is that it wouldn't let you leave the screen, even if you could get across. I guess it would just be a matter of extending that platform and closing up the gap. Then Joe could simply run across, right? Forgive me if I'm wrong...I have 0 programming skills.

#33 A.J. Franzman OFFLINE  

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Posted Mon Nov 22, 2010 4:44 PM

It might be possible in Stella to do something simple, like find and modify Joe's X-coordinate while the game is running, to simply make him teleport across the gap.

#34 Thomas Jentzsch OFFLINE  

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Posted Mon Nov 22, 2010 5:03 PM

My guess is that it wouldn't let you leave the screen, even if you could get across. I guess it would just be a matter of extending that platform and closing up the gap. Then Joe could simply run across, right? Forgive me if I'm wrong...I have 0 programming skills.

I just made a very brief test. Hacking the graphics doesn't do the trick. You have to find and change the internal map representation.

#35 Tempest OFFLINE  

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Posted Tue Nov 23, 2010 8:47 AM

My memory here is fuzzy, but I could have sworn someone hacked it so you could get over there and indeed it wouldn't let you leave the screen. It acted like a wall was there.

Tempest

#36 Thomas Jentzsch OFFLINE  

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Posted Tue Nov 23, 2010 9:57 AM

The game uses a clever mix of sprite collisions and map definition data to open/close passages. You can test this within an emulator by enabling/disabling the various graphics objects.

The right wall can be disabled that way too, but even if it is not visible anymore, you cannot move further to the right. So either something is defined in the the map definition data or not.

#37 stephena OFFLINE  

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Posted Tue Nov 23, 2010 10:41 AM

Maybe a little off topic, but I just wanted to add that this is main reason I originally wanted to add a debugger to Stella. More recently it's been to help developers with homebrew games, but my original desire was to play games, test the limits, and "poke it and see what happens". So if anyone has any ideas how to improve the debugger to this end, please let me know.

#38 Thomas Jentzsch OFFLINE  

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Posted Tue Nov 23, 2010 1:53 PM

I did some searching:

http://www.atariage....ost__p__1564609

Problem solved! :)

#39 Ranthulfr OFFLINE  

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Posted Wed Nov 24, 2010 2:59 PM

Oh good, now that I know the truth I can sleep again! Sure would've been a good place for an easter egg though (albeit one that nobody could uncover).

I did some searching:

http://www.atariage....ost__p__1564609

Problem solved! :)



#40 R.O.T.S OFFLINE  

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Posted Fri Nov 26, 2010 4:27 AM

In Haunted house, after you collect the pieces for the urn if you allow one of the monsters chase you to the exit and if the monster is over top of where your "eyes" are when you start the next round by pressing and holding reset you will see your "eyes" have some graphical changes. Upon releasing the reset switch you will lose a life. It has worked for me on all the variations I have tried it on.


HH one of my favourites but is this simply the flicker of two overlapping sprites and the loop of the reset button?

#41 Nukey Shay OFFLINE  

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Posted Thu Jan 13, 2011 3:34 AM

Oh good, now that I know the truth I can sleep again! Sure would've been a good place for an easter egg though (albeit one that nobody could uncover).

Indeed. Consider if the game had used a method similar to Adventure's...where simply moving to the right is not enough to uncover a secret room (the dot must also have been moved out of it's starting screen). The game could have had such a triggering mechanism to eliminate the "invisible barrier" very easily if the programmer had wanted - just ignore the game world map and check if the criteria has been met (such as specific objects in inventory).

Fortunately, this "special exception"-type code is usually pretty easy to discover via disassembly (Adventure's "move right" code is longer than any other direction). Without stumbling upon such a trigger, one might never discover such a secret simply by playing the game...or even by hacking the horizontal location variable to blink yourself there ;)

In this case, the "non-secret" revealed itself purely by chance when just hacking the variable. Disassembling the game is the only way to be sure of anything.

#42 Chris++ OFFLINE  

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Posted Fri Jan 14, 2011 3:13 PM

So, if Panama Joe could move to the right -- i.e. the invisible barrier were removed -- would the game simply crash, or would Joe simply appear in a room that the programmer hadn't intended on being adjacent (i.e. a map-related "wrap around" of some kind)?

#43 Thomas Jentzsch OFFLINE  

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Posted Fri Jan 14, 2011 3:16 PM

So, if Panama Joe could move to the right -- i.e. the invisible barrier were removed -- would the game simply crash, or would Joe simply appear in a room that the programmer hadn't intended on being adjacent (i.e. a map-related "wrap around" of some kind)?


Probably the later.




#44 gHan2000 OFFLINE  

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Posted Sun Feb 6, 2011 6:02 PM

Adventure: Famous “secret dot and room”. One game 2 or 3, find the dot in the Black castle’s catacombs. Next, drop the dot and two other objects (except the bridge with the sword, Chalice, or magnet) in the room down and to the right of the Gold castle. Pass through the barrier to reveal the message, “Created by Warren Robinett”. A dragon can also be used instead of 2 objects. You can also pass through the lower right barrier underneath, although there’s no room behind it. {Adam Clayton}


That's a little to well known...

Edited by gHan2000, Sun Feb 6, 2011 6:03 PM.


#45 Nukey Shay OFFLINE  

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Posted Sun Feb 6, 2011 6:14 PM

What's not so well-known is that the dot does not need to be present...it just needs to be moved out of it's starting screen. You can use the bridge in the catacombs below the entrance to get behind the panel and enter the signature room.

#46 orionpax55 OFFLINE  

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Posted Sun Feb 13, 2011 12:41 AM

I've a video showing the Mountain King easter egg, if anyone cares.

#47 thebiggw OFFLINE  

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Posted Sun Feb 13, 2011 10:38 PM

In Haunted house, after you collect the pieces for the urn if you allow one of the monsters chase you to the exit and if the monster is over top of where your "eyes" are when you start the next round by pressing and holding reset you will see your "eyes" have some graphical changes. Upon releasing the reset switch you will lose a life. It has worked for me on all the variations I have tried it on.


HH one of my favourites but is this simply the flicker of two overlapping sprites and the loop of the reset button?


I am not entirely sure but it would make sense. I have zero programming abilities so I would be the last one to ask. I found it as a kid and used to play it all day long just to see if it worked on every "level" (aka select switch option) the game has and it did for me.

#48 mtshark7 OFFLINE  

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Posted Wed Jun 8, 2011 8:13 AM

Does anyone have any videos of these easter eggs? I think that would be better then just a word description of whats happening. I would definately like to try them but I think a video would be ideal for that :-)

I saw the video orionpax posted for mountain king....any others?

ADD: The mountain king one was also mentioned in AVGN's game glitch video.

Edited by Mark T, Wed Jun 8, 2011 8:15 AM.


#49 dwane413 OFFLINE  

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Posted Wed Jun 8, 2011 8:31 AM

Does anyone have any videos of these easter eggs? I think that would be better then just a word description of whats happening. I would definately like to try them but I think a video would be ideal for that :-)

There is a video near the bottom of Random Terrain's E.T. Tips and Reminders page. The video is called "Easter Eggs and Ninja E.T."

You might be able to find more videos on YouTube.

#50 Tony The 2600 OFFLINE  

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Posted Mon Sep 26, 2011 2:26 AM

I know one i used to do as a kid on Adventure ,it is not much and only a glitch but i thought i will share.

Some may know this and already experimented with Adventure doing this but you can get into the top of the black castle.
just get the bridge ,carry it to the red room on the bottom right of the map and lay it across the bottom wall.

Can do it to the yellow and white castles also just by experimenting going through walls with the bridge




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