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Doom hacking notes


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#26 JagChris OFFLINE  

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Posted Sat Oct 27, 2018 10:04 AM

That confirms that despite the hardware bugs of the serial link, they found a working stable workaround that completely avoided the hardware crash.

So, this effort must be reproducible. Whi!e i won't mess with networking for my first two games, I should be able to carve some networking experimenting for third one.


You could possibly contract Tursi to do it. He could figure it out. He's a networking expert. See if he would sign an NDA or something.

#27 VladR OFFLINE  

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Posted Sat Oct 27, 2018 10:23 AM

Only Aircars which uses the same code as BS from what I know.
The BS network works reliable but I also saw it crash once or twice. I had a friend at my place and on a two console network one ship froze while in gameplay. But in general it is very stable no comparasion to Doom on the Jag.

Thanks, so despite their best efforts, they didn't come up with 100% stable networking code.

It's entirely possible then, that given the hw bugs, that's the best possible scenario on jag.

#28 JagChris OFFLINE  

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Posted Sat Oct 27, 2018 10:32 AM

Thanks, so despite their best efforts, they didn't come up with 100% stable networking code.

It's entirely possible then, that given the hw bugs, that's the best possible scenario on jag.


I have not heard anyone else observe any problems with their networking crashing. Some have played these with jagfests for hours with multiple linkups with no apparent problems reported. There are videos on YT.

#29 PeterG OFFLINE  

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Posted Sat Oct 27, 2018 10:37 AM

Well as I said it is very stable. Encountering an errors once or twice doesn't make it unstable.
Could be anything really, the cable, the catboxes, the jaglinks what do I know...
I feel like you both jump to the wrong conclusions.

#30 VladR OFFLINE  

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Posted Sat Oct 27, 2018 10:39 AM

You could possibly contract Tursi to do it. He could figure it out. He's a networking expert. See if he would sign an NDA or something.

Ok, the basic networking is far from rocket science. You send a packet of bytes from one and receive them on another.That's like a page of code.

The challenge on jaguar is figuring out exactly what payload or other elements cause the crash. Remember the gpu in main rules? We need something similar for networking.

There could be dependencies on other chips in the system that break it, for example.Just pulling it out of my ass now, but perhaps increased bus load or using certain blitter modes exacerbates this.

Either way, you start the networking sample as empty as possible and start adding functionality and see what breaks it and based on how reproducible the behavior is, you can start designing workaround s.

By January, I am going to have to get a second jaguar - the PAL one. Then I will be set for networking experimenting and perhaps my third game around summer, could have somewhat stable networking.

Besides, I swear I recall a thread where ZeroSquare mentioned he did some work on it and even posted some code with findings?

#31 VladR OFFLINE  

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Posted Sat Oct 27, 2018 10:42 AM

Well as I said it is very stable. Encountering an errors once or twice doesn't make it unstable.
Could be anything really, the cable, the catboxes, the jaglinks what do I know...
I feel like you both jump to the wrong conclusions.

Well, if it crashed just once, then it's not 100%. Could be 95%, but not fully crash free...

Of course, one doesn't need hw bugs for crashes. Just trigger an exception without traps on 68000 and see what happens :)

#32 PeterG OFFLINE  

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Posted Sat Oct 27, 2018 11:03 AM

Man you make me regret answering your question.:) So again, I don't know what triggered the crash, it doesn't have to be in the software. I don't know, I can just tell what I saw.

#33 JagChris OFFLINE  

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Posted Sat Oct 27, 2018 11:33 AM

Well as I said it is very stable. Encountering an errors once or twice doesn't make it unstable.
Could be anything really, the cable, the catboxes, the jaglinks what do I know...
I feel like you both jump to the wrong conclusions.


No worries. You just gotta give it context. You may have been one of the few people who remember run into a networking error and you happen to be here now. Instead of say 5 people who remember no problems then you. That would be context.

My point is there are people out there who are contrary just to be that way. Even say a one in five testimony of 'I remember an error happening once' will have some people going 'oh look at that it doesn't work'.

My stance is I'm not drawing the wrong conclusion from what you said, I just believe I have a good idea of what others might use it for.

#34 VladR OFFLINE  

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Posted Sat Oct 27, 2018 11:51 AM

Man you make me regret answering your question.:) So again, I don't know what triggered the crash, it doesn't have to be in the software. I don't know, I can just tell what I saw.

Why regret? Given we are talking about networking, isn't that the most probable scenario? Of course, we can't fully know, no argument there :)

Unfortunately, this game isn't as widespread as others, so we miss more statistical data.

As I already said, it is very easy to crashing jag using just 68000 code without traps. A wrongly aligned value to address register and boom...

Thanks for feedback, though.

#35 VladR OFFLINE  

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Posted Sat Oct 27, 2018 11:56 AM

Ok, I will keep it simple, so it won't get lost in a wall of text again:


Is there a jaguar game that nobody ever saw crash during network play over course of hundred hours of network play?

If yes, then it's confirmed to be possible to have a 100% stable networking.

#36 PeterG OFFLINE  

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Posted Sat Oct 27, 2018 3:27 PM

Seriously? We do have three games that network at all, of those one is unstable and the other two work almost flawlessly in network mode and still you ask this question. And then you ask me why I might regret answering the first question? Well guess you will have to write your own 100 percent, flawlessly working, errorless, stable, never once failing network code to see if such a thing is possible on Jaguar. :)

#37 Mitch OFFLINE  

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Posted Sat Oct 27, 2018 4:23 PM

If I remember correctly, Carl said that it was a software bug that causes the Doom network crashes not a hardware bug.

 

Mitch



#38 Saturn OFFLINE  

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Posted Sat Oct 27, 2018 4:25 PM

Not to interrupt ( :lol:) but I did manage to find how to rename the maps in the source. So, I made up names for all the levels I did, compiled it and also added custom end game text.

Got the game to end after certain levels too. Map 12, 13, etc. These feel like real mission packs now :)

 

rom 1
"New Depths",
"Deadly Path",
"Base Entrance",
"Bastard Land",
"Blast Doors",
"Into the Bowels",
"Left For Dead",
"Secrets Abound",
"Security Stronghold",
"Taking the Base",
"Greenhouse Effect",
"Nuclear Station",
"Out of the Frying Pan",
"End Game Sequence"

01_zpsryktwwzc.jpg

 

rom 2
"Into the Fire",
"Base 2 Entrance",
"Incubation Chambers",
"Imminent Pain",
"Hell Awaits",
"Merciless",
"Left For Dead 2",
"Watch Your Step",
"Havoc",
"Close Quarters",
"Dungeon Maze",
"Bloodletting",
"End Game Sequence"

02_zps9z7jrptp.jpg

 

rom 3
"Behemoths",
"Base 3 Entrance",
"Infirmary Horror",
"Its A Trap",
"Raging Titan",
"Burnt Offerings",
"Prison Break",
"Cesspool Hazards",
"Sewer Escape",
"Halls of Peril",
"Dis Membered",
"The End Is Nigh",
"Grand Theft UFO",
"End Game Sequence",

03_zpsaz40noip.jpg

 

rom 4
"Shoot the Glass",
"Base 4 Entrance",
"Segue Interrupted",
"Pink Is the New Dead",
"The Unforgiven",
"Tower Massacre",
"Cross Into Madness",
"Clock Is Ticking",
"Kill Em All",
"Catacombs",
"Swarms and Titans",
"Battle At Mt Fuji",
"End Game Sequence"

04_zpseecvys1l.jpg

 

rom 5
"Base 5 Entrance",
"Inner Sanctum",
"Demon Megaplex",
"Fortress of DOOM",
"Utter Chaos",
"Mountain Pass",
"Ruthless Agression",
"Enter the Arena",
"Ransacked Armory",
"Quick and Painful",
"Splash Damage",
"King of the Hill",
"End Game Sequence"

05_zpseh0nhx8v.jpg

 

rom 6
"Swallowed In Hell",
"Base 6 Entrance",
"Trial By Fire",
"Evil Unleashed",
"Titan Offensive",
"Violent Pacification",
"Close Quarters 2",
"Full Scale WAR",
"Spill the Blood",
"Bloodshed",
"Weapons Hot",
"Annihilation",
"End Game Sequence"

06_zpsrkrnjwdi.jpg

 

rom 7
"Base 7 Entrance",
"Torture Chamber",
"Lava Basin",
"Wicked Fortress",
"Hell Is Here",
"All Hope Lost",
"After the Storm",
"Lethal Alleyways",
"Garrison Strike",
"Of Ash and Stone",
"No Turning Back",
"The Final Conflict",
"End Game Sequence"

07_zpszifuatnm.jpg



#39 VladR OFFLINE  

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Posted Sat Oct 27, 2018 6:11 PM

Seriously? We do have three games that network at all, of those one is unstable and the other two work almost flawlessly in network mode and still you ask this question. And then you ask me why I might regret answering the first question? Well guess you will have to write your own 100 percent, flawlessly working, errorless, stable, never once failing network code to see if such a thing is possible on Jaguar. :)

And how exactly might I actually know that there's 3 (or, say, even more) such games ? We are talking about Doom here, so that one is given. BS I obviously heard about.

 

Doesn't mean that there isn't some other networked game, now does it ? Could be a feature in some rare or lesser known game, for all I know...

 

You make me regret actually asking the question, but I'll leave it alone, given your current aggression levels...

 

And how do I know that you actually know and aren't just bullshitting me? See how that works :) ?



#40 CyranoJ ONLINE  

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Posted Sun Oct 28, 2018 3:03 AM

You could try using Google. It does involve reading though.




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