Jag Wolfenstein demo mode gets stupid?!

[+-^CrossBow^-]

So I've had my Jaguar and my Wolfenstein cart since like 2001 or so.

 

If you've ever let the game go into demo mode, the demo is pretty cool as it shows the main character just ripping through some levels and taking out the nazi's left and right. Really shows off the faster framerates of the Jaguar version in action..etc.

 

Well while plugging in my new scart rgb cable last night I turned on the jag to test it. However I got a black screen and without even thinking I then pushed my Wolfenstein cart in with the Jag in the On mode. Well it just gave a black screen and quickly realizing my mistake I turned it all off and then turned it back on. The game came up, looked and sounded great on the new scart cable! Yeah!!! then I let the game go into demo mode...

 

And now the character just bumps into walls, never opens a single door and just shoots randomly with the pistol at nothing LOL! One of the demos takes forever to go away because he never leaves the room he is in and just kinda goes in circles again firing off random shots at the wall and into the doors. Eventually the game times out and goes back to the title screen but by then he is outta ammo and just knifing the air randomly?! LOL

 

Naturally my save games were wiped out as well because of this and it does still save properly thankfully. But yeah..apparently plugging in a wolf 3D cart with the Jag on already will wipe out the demo's gameplay.

 

Anyone ever seen this happen before? Certainly is amusing to watch and no..it isn't just random. He does the same stupid movements and firing blank shots each time. I fired it up again this morning before leaving for work and it is the same so..the hosed up gameplay appears to have been made into the new default demo game play mode LOL.

 

[Hyper_Eye]

In the Wolfenstein 3D and Doom games the demos were not recorded gameplay obviously. The player's actions were stored and then they are played back in game. In order for the demos to work properly the code has to produce the exact same results as it did when the demo was recorded. So the player speed has to be exact, the random number generator has to produce the same sequences, objects have to work at the correct speed (doors, stompers, etc.), monsters have to respond exactly the same. If the code is not functioning correctly the demo will go off. If it goes off even a tiny bit the problem will compound and the demo will get progressively worse. The Doom source port I code on, Odamex, is one of the few source ports to have vanilla Doom demo compatibility. We have regression tests which run through a series of demos (headless and at super speed) and produce checksums that are compared against the known good values for those demos. If they are off we know we broke demo compatibility. It could be that we introduced a bug into the code or we pulled an extra random number that threw the sequence off. I've sat there watching demos to find the exact moment that it goes off before.

 

My suspicion is that the cartridge is not seated quite right. My Ruiner Pinball cartridge has this problem where I insert it and it seems like it is working fine but there are actually some things that are messed up. For example the scoring is way off. It seems like you are scoring big but really the game is just dishing out points like candy. The ball physics are also totally goofed. If I turn the game off and push the cartridge over to the right it fixes the problem. I guess the board has gotten worn down some. You can bet that if the demos are off in Wolf3D the gameplay is off as well. Try fiddling with the cart.

Edited December 12, 2018 by Hyper_Eye

[+-^CrossBow^-]

Well I was playing the game just fine although it did seem like there were way more enemies than normal in the levels. Rooms that usually only had two enemies would have like 4 in them. But I was playing on normal difficulty and I might have been playing previous games from saves I did in easy mode?

 

The demo isn't just off...it is...totally wrong. But the normal game did play normal. Doors opened and closed normally, the secrets etc were all still there. It was just the demo was totally hosed up. My guess is that is stored in a section of the cart that isn't mask data and it was corrupted when I plugged the cart in with the Jag already powered on. As I said it wiped out all of my save files as well. I will try the reseatting of the cartridge, but I don't leave my carts plugged in. I pull them loose when I'm done playing and just sitting in the slot. When I pushed it into the console this morning it was doing the exact same bumping into walls routine.

 

Is there some gameplay that I can check for to see if that is affected as well? It just appears the demo is wiped and the rest is fine.. but I'd like to check and be sure. I was pissed it deleted the saves because I was on the third episode as I recall. Had just started it anyway.

[Zerosquare]

Can you capture a video of the demo? While I don't have an explanation, it's the kind of freaky thing that should be preserved

[+-^CrossBow^-]

Sure I can take video of it tonight to show what I'm talking about. Again it is like the original demo gameplay programmed in the cart has gotten corrupted and the game doesn't quite know how to play in demo anymore. What it does play, it does so in the exact same manner each time on each of the 3 different demos it scrolls through.

 

Also worth noting that it does still go through 3 demos before cycling back and those demos are on the correct levels. But the actions of the character are not there. The most basic issue, is that he appears to not know how to open doors in the demo because he does goes straight to the first door in the first demo and fire off a couple of shots. Then it opens on its own from the guard that was in that room he was originally trying to kill and he does shoot and kill him. Then he backs up..the door closes and he is stuck in that room.

 

Now that I think about it...maybe the issue is that he is going through the motions, but the door isn't opening for him and thus he is essentially stuck. I will have to watch the other two demos again to see if he is approaching the door at the beginning on each and it just isn't opening for him.

 

But they do open in actual game play just fine.

[Gummy Bear]

It was exactly the same on my Wolfenstein cart before I sold it.

Demo guy was obviously missing his white cane, but everything was fine once in game.

 

Maybe it has something to do with refresh rate making the demo run faster or slower than it should?

 

Are you rocking 50 or 60hz, Crossbow?

[+-^CrossBow^-]

NTSC 60hz all the way. It was running the demo fine prior to my insert during power on incident and hasn't since. I will take video tonight to see if it what any of you might have seen before.

 

Wait so you have seen something like this before? It honestly is acting like some part of the game code is corrupted now that only seems to affect the demo playback mode and not the actual game.

 

The only other changed variable....

 

Is that I'm using my new Retro Gaming Cable for RGB scart that I received yesterday. I could plug it up back to the way it was and see if that makes a difference in someway? But that would be pretty crazy if a video cable could literally effect the game like that.

Edited December 12, 2018 by -^Cro§Bow^-

[Hyper_Eye]

Well I was playing the game just fine although it did seem like there were way more enemies than normal in the levels. Rooms that usually only had two enemies would have like 4 in them. But I was playing on normal difficulty and I might have been playing previous games from saves I did in easy mode?

 

The demo isn't just off...it is...totally wrong. But the normal game did play normal. Doors opened and closed normally, the secrets etc were all still there. It was just the demo was totally hosed up. My guess is that is stored in a section of the cart that isn't mask data and it was corrupted when I plugged the cart in with the Jag already powered on. As I said it wiped out all of my save files as well. I will try the reseatting of the cartridge, but I don't leave my carts plugged in. I pull them loose when I'm done playing and just sitting in the slot. When I pushed it into the console this morning it was doing the exact same bumping into walls routine.

 

Is there some gameplay that I can check for to see if that is affected as well? It just appears the demo is wiped and the rest is fine.. but I'd like to check and be sure. I was pissed it deleted the saves because I was on the third episode as I recall. Had just started it anyway.

 

This behavior is consistent with a demo going out of sync as I described. Consider this... if the demo has BJ pushing forward for 20 ticks and his movement rate is typically X but instead he moves at a slightly slower rate of Y, then the demo has the action input to open a door... he is not going to be at the door when that action is issued and it will do nothing. Say that after he opens the door he is supposed to proceed forward. Well you will see him reach the door and just walk into it. Then say his next movement is supposed to be to turn right and walk down a hallway. You are going to see him turn right but there is no hallway. There is a wall. So he will just be running into it. Then the demo has BJ firing his weapon at an enemy. Well BJ never went through the door, never walked down the hallway, never sighted the enemy... so now he is shooting at a wall. The demo file is playing through the correct actions but since BJs movement speed wasn't exactly correct in that initial walk up to the door everything after that is completely screwed up. That is how dependent demos in Doom and Wolf3d are on precise code behavior. Something as small as a tiny floating point precision error can totally throw a demo. It may not be enough for you to notice a change in gameplay but it matters in a demo. Sometimes the error is small and it takes a while for the demo to start showing that it is off. Sometimes something like opening a door is missed or an enemy doesn't move the way it is supposed to and kills the demo player prematurely so it's really obvious that the demo is off. Either way it indicates that the code is not working as intended/expected. I'll optimize some floating point precision away on the Xbox port of Odamex (default optimization settings on release builds for Xbox causes consistent demo problems) and record some of the vanilla demos in action. You will see exactly the same sort of shooting of walls and walking in circles that you are witnessing. In one demo Doom guy dies way earlier than he is supposed to with that particular Xbox precision error. Some ways you could see this manifest in game is that enemies could end up in slightly different spots than you expect if you have played a section many times before. Maybe enemies do more or less damage than they usually do. Same thing for the damage you do. It would be stuff like that. It's not as obvious in game at all because the player's actions act as a seed on the responses in the game. Your own movement and actions randomize the action.

 

With my Ruiner Pinball cart it tends to go into the slot so that the errors occur. With that cart I insert and then push right. Fixes the issues every time. I really think that the edge of the board is a little worn so the cart is not centered correctly. I don't know if that is the issue in your case but it's worth experimenting with.

Edited December 12, 2018 by Hyper_Eye

[+-^CrossBow^-]

I did state I was playing on normal mode. Well the first enemy in the first episode..the dual gatling gun wielding guy. He died a lot easier than I remember. I think I had a full compliment of 250 ammo and he was down in just about 2 or 3 seconds of continuos fire from my own gatling I had just found. I think he only took about about 10 health too in the firefight off me. So....hmmm...

 

Could it actually be something in the Jag itself that is causing this from when I popped the cart in with the power on? Wonder if there are any other games I can try that might exhibit similar behavior? I don't have Doom but I've several others.

[Hyper_Eye]

I did state I was playing on normal mode. Well the first enemy in the first episode..the dual gatling gun wielding guy. He died a lot easier than I remember. I think I had a full compliment of 250 ammo and he was down in just about 2 or 3 seconds of continuos fire from my own gatling I had just found. I think he only took about about 10 health too in the firefight off me. So....hmmm...

 

Could it actually be something in the Jag itself that is causing this from when I popped the cart in with the power on? Wonder if there are any other games I can try that might exhibit similar behavior? I don't have Doom but I've several others.

 

Well Doom would be the perfect game to test for this. I don't know offhand what other games would be affected by an issue like this. Any game that plays a demo in a similar manner to those id games I suppose. I think Cybermorph has a demo that starts up pretty quick.

[+-^CrossBow^-]

Yeah...cybermorph and likely battlemorph as well perhaps. Then again I'm not that familiar with their demos to know if something is off with them unless they are totally obvious like Wolf 3D's is. To test the cartridge port theory I could also try the game with the CD removed just to remove as many variables as possible.

[+Stephen Moss]

Could it actually be something in the Jag itself that is causing this from when I popped the cart in with the power on? Wonder if there are any other games I can try that might exhibit similar behavior? I don't have Doom but I've several others.

If it is a fundamental problem with the Jag then I would think you would be seeing something amiss in all cartridges, i.e. the character/object your are controlling does not react as expected, items not reacting to your position/being displayed in the wrong place, pace of game play different. If you are only noticing differences in the game play or attract mode of just that cart then it has to be a cart issue.

 

Naturally my save games were wiped out as well because of this and it does still save properly thankfully. But yeah..apparently plugging in a wolf 3D cart with the Jag on already will wipe out the demo's gameplay.

I maybe wrong but I would think there are only two likely possibilities (assuming the Jaguar itself is OK) for such consistent behaviour, the first is that the entire attract mode is coded into ROM in which case the problem could be symptomatic of major cart/ROM issue.

The second is that the game play for the attract mode is standard and pulled from the ROM, but your characters behaviour/location data for the attract mode was stored in the EEPROM and has probably been corrupted as you say you have lost your game saves resulting in the issues you are seeing.

If the game appears to function correctly when you are in control and only has issues while in attract mode I would suspect the latter, if regular game play is also off then I would suspect the former.

[+-^CrossBow^-]

Here is video of this in action. Pretty sure it was exactly what Hyper_Eye was talking about. But it wasn't the way the cartridge was sitting in the slot as it would do the same exact thing in the jaguar itself just like it did through the jag CD. You can see that BJ basically goes through the motions following his script but due to some data corruption in the save file data on the cart, something is off on the timing preventing the demos from running correctly..

 

 

 

 

I was able to eventually fix this later this evening by doing the cartridge clear memory steps as outlined in the manual. Press *, Option, and # on the game select screen.

[+-^CrossBow^-]

If it is a fundamental problem with the Jag then I would think you would be seeing something amiss in all cartridges, i.e. the character/object your are controlling does not react as expected, items not reacting to your position/being displayed in the wrong place, pace of game play different. If you are only noticing differences in the game play or attract mode of just that cart then it has to be a cart issue.

 

I maybe wrong but I would think there are only two likely possibilities (assuming the Jaguar itself is OK) for such consistent behaviour, the first is that the entire attract mode is coded into ROM in which case the problem could be symptomatic of major cart/ROM issue.

The second is that the game play for the attract mode is standard and pulled from the ROM, but your characters behaviour/location data for the attract mode was stored in the EEPROM and has probably been corrupted as you say you have lost your game saves resulting in the issues you are seeing.

If the game appears to function correctly when you are in control and only has issues while in attract mode I would suspect the latter, if regular game play is also off then I would suspect the former.

 

It was indeed the cartridge itself. Apparently when the save data got corrupted, it also affected the demo playback. I finally read up in the manual on how to do a complete cart settings erase and once I did that, the game demos play normally again.

 

However, my cybermorph cart refuses to work through the JagCD at all! And it took some doing to get it working in the main Jag itself. I cleaned everything including the cart slot and still had to angle the Cybermorph cart slightly to get it to finally fire up but not through the JagCD. I think this was mentioned elsewhere not too long ago?

 

You can't tell from the video of course, but the Jag had actually been running for about 4 hours solid at that point as I forgot to turn it off earlier in the day! Anyway, the point is that the jag is fine and so is the scart cable I got from retro gaming cables. In fact the jag might have the next best picture I've seen through the OSSC next to my Genesis through component.

[Zerosquare]

I can't see any good reason why the save data should influence the demo, but from your description, it definitely sounds like it's the case. Weird.

Edited December 14, 2018 by Zerosquare

[+-^CrossBow^-]

I can't see any good reason why the save data should influence the demo, but from your description, it definitely sounds like it's the case. Weird.

That is why I made a video of it. Pretty obvious in watching it that BJ does go straight for the first door but then something is off that prevents it from opening. As a result he would wander aimlessly in the room he is in following the rest of his scripted commands.

 

But yes..once I did the *,Options,# buttons combo on the game selection screen, I got the message that the data was being erased and after that, the demos are working correctly again. So yeah. popping the cart in with power zapped it strangely but was recoverable.

[Hyper_Eye]

I can't see any good reason why the save data should influence the demo, but from your description, it definitely sounds like it's the case. Weird.

It makes sense. The EEPROM data was clearly corrupted. In there you have your 3 save game slots and your sound settings. So the game starts and it has some global data it loads into memory. It checks to see if you have saved games so it knows whether to make them available for selection on the menu. Somewhere in the save data is a variable that represents the size of an array or buffer of data. Since the data is corrupted that value is bogus. The code writes junk into memory and, due to a bad length indicator, runs off into memory it shouldn't be writing to and puts junk there. The demo starts, reads a bad value from memory, produces behavior that is not consistent with the expected behavior... boom. Demo desync. Stack and heap corruption is definitely something we have to look for when debugging demo desyncs. They can be quite difficult to pin down but this one would be pretty easy based on the sequence of events that were described.

[sirlynxalot]

I used to let the 32x game Knuckles Chaotix go to demo mode and it was a similar experience. The characters didn't move around the level like they were trying to play through the level, they'd do nonsensical stuff like get trapped walking into walls for 20 seconds and other stuff like that. I just figured the game was rough around the edges since the platform wasn't supported long and sega was quick to release stuff without extensive QA.

[Gummy Bear]

That sounds like anyone trying to play Chaotix.

That elastic ring mechanic sucked the fat one.