hi guyz,
i have a little problem with my PAL chrono trigger.
im telling the story from the beginning:
in january this year i startet to build a chrono trigger pal.
the game was the first i ever build for the snes, and at the beginning it seems to work properly.
but after 5 hours of play... the game freezes and never startet again.
i have tryied to solder the eprom to another donor board (nhl 96).
and the game startet.
this time, after 1 hour of playtime, the game freezes and never startet again.
i have trashed the eproms after this failure.
one week later i startet to build another one, this time with
another rom from an other source.
i soldered all together and put it in my snes.
it starts... the chrono clock was ticking!
i played 5 - 10 min, when you get to leene square... run into marle
and so on... but at the leene square the game freezes!
but why? i dont know... so i trashed the eproms again.
a friend of mine, has send me a new file, already patched and 100 % working. (in his case, it works).
so i soldered this one together.
i hace played it now 14 hours... looked in lavos eye, mouth, ass... dont know what it is ^^ and the game crashes!
now it will not start!
i dont get it, what is the issue with that?
why is it working for hours, then crash and let me sit with open mouth!?
i dont have played football with the cartridge ... there was no earthquake here... the game was only in my snes.. this makes me crazy!
12 eproms did chrono trigger take.. i dont want to make it one more time.. anyone here has any ideas?
i smash my head against a wall...
At least the original (unhacked and untranslated) NTSC Chrono Trigger works fine on my PAL SNES with an adapter, with the exeption of some minor sound glitches here and there.
yeah the original version from my brother runs perfectly too on my snes... it might be the translation, but why is there such a delay?
sometimes it works 14 hours, sometimes 10 min...
i cant figure out why.
That's weird but it sounds like a wrong contact or something like that.
mmhhh i think i got the issue, but how to fix it?
the sram is the error... after the game freezes, i hit reset and nothing happened.
take the cart out... blow in... put it back.. game starts, but all savegames are lost.
somethings shits up the sram but what? and how?
today i have checked all wires (with my eyes and multimeter) and so.. no error.
That SRAM issue is not unique, I had the same problem with a few NES games : When the crash the saves are erased (very likely the CPU is going crazy and accidentally write into SRAM).
Now to guess what causes the CPU crash I can't do it for you... if it systematically crashes at the same place this is a software error. If it crashes randomly it's more likely to be an hardware fault.
when i do nothing, the game freezes.
i play 10 min... go smoking.. come back... freeze!
all savegames lost and i must delete the sram with a 9v battery.
when i play without a pause, the game works nice.
Quote:
all savegames lost and i must delete the sram with a 9v battery.
What are you talking about ? A 9v battery ? The SRAM should be backed up with a 3V battery. If you don't do that it's no surprise there is problems.
the game has a standart 3v battery.
i use a 9v battery to delete the sram. not to save the sram!
i have read this in a tutorial on ultimate-console, that this is the best way to completely delete the sram.
Oh my god this is so horrible ! I should tell the guy who made that article that he his comletley crazy and that this can likely kill your ships or something.
You can erase saves in CT by pressing start + select on second controller if you really want to.
The best way to erase SRAM (why would you ever need to?) is to disconnect the battery and go do something else for 10 minutes or so. Then connect it again. You definitely shouldn't apply more voltage.
ok ok.. one moment ^^
i must delete the sram, cause its full of garbage data...
the game cannot boot up while the data is in there.
so i have deletet the sram manually via a 9v battery.
i hope that i have not burned up any chips on the pcb with the 9v
battery.
next time i desolder the battery for 10 min and it should be fine.
but this problem cant be the issue, why chrono trigger crashed for
the first time... i have only used the 9v battery after the crash, not before.
I've never heard of corrupt data stopping a game from booting. Generally a game will have a checksum to determine if saved data is valid and not attempt to load that data if it fails and generally it will be erased if corrupt.
No idea what your problem is though. If your ROM is translated maybe the translation doesn't work on real hardware properly.
MottZilla wrote:
I've never heard of corrupt data stopping a game from booting. Generally a game will have a checksum to determine if saved data is valid and not attempt to load that data if it fails and generally it will be erased if corrupt.
That doesn't help if the save data passes the checksum but is otherwise inconsistent, such as an armor type that's unused, or any of several attributes that are supposed to be two digits but are actually between 100 and 255. Real world glitch example: Catching Missingno. in the Pokemon games for Game Boy will screw up your Hall of Fame even if it doesn't screw up the checksum.
Good point, I suppose the kinds of checks they do aren't very solid. But I can't think of why Chrono Trigger save data could cause the game to not boot or crash and be unsolvable by starting a fresh game.
Several RPGs show some basic stats from all files on the file select screen. Final Fantasy VII for PS1 acts this way. If your file is corrupted enough to crash the subroutine in CT's file select screen that displays information about a file, it could cause behavior like what you describe.
I didn't think about that but it makes sense to me now. Seems like a pretty nasty flaw in the game's code to me that it can't handle that. I think it should have been a concern of theirs even though most people wouldn't run into the issue, it could certainly happen outside of building a repro.
Maybe this has to do with a name that does not contain only standard letters A-Z or a-z ? Just my 2 cents.
Also I'm pretty sure that CT does more than just a simple checksum to verify the validity of saves. With FF2 on the NES I was able to increase my HP and by decreasing another byte the same amount, the checksum was passed and the save was considerd valid. This didn't work for CT. Maybe it checks the sum of all bytes and the XOR of all bytes and both tests have to pass ?
Bregalad wrote:
Maybe it checks the sum of all bytes and the XOR of all bytes and both tests have to pass ?
That's what Mario Paint does. Some games might use CRC. But no matter what hash algorithm you use, the hash of an inconsistent data set is still a valid hash.
I've built several custom SNES cartridges in the past and so far, I've never ever had to erase the SRAM in order to get the new game to work on the "donor" PCB.
Cali wrote:
the game cannot boot up while the data is in there.
What makes you believe that?
Cali wrote:
i must delete the sram, cause its full of garbage data...
If you have access to the SRAM on the cart (which you obviously have, otherwise you wouldn't be able to know that there is "garbage data"), why don't you just upload an empty SRM file onto it (i.e., a file filled with $FFs)? This would be the easiest and most hardware-friendly way to erase the SRAM.
Anyway... From what you describe, I'm pretty sure that the cause of your problems is to be found on the hardware side. Either you've blown the cart by using that 9V battery of yours on it, or those freezes are caused by poor contact between the cart and the SNES (which they are in 99.9% of all cases).
My last assumption would be that your console is faulty. Try playing Super Mario World on it for at least 14 hours and see whether you encounter a freeze/crash.
Sorry to re-float this thread. I don't know if it is against the rules, but I thought it would be better to post here.
I have EXACTLY the same problem with my Chrono Trigger repro. I did two of them: one on a japanese version of the game, and the other one on a japanese version of Dragon Quest VI (both use the same board). I changed the CIC in the first one to make it PAL, and the other donor board remained unchanged.
Well then, now the PAL version works properly, but not the NTSC one, which was done using Dragon Quest VI's PCB. I think it has something to do with SRAM too. The game checks $30:7FF8/FA/FC on SRAM and I think if data there is not the expected data, the game hungs.
I also have random hungs while playing, like our friend Cali.
The ROM I'm running is tested on a GameDoctor, so the problems aren't caused by the spanish patch.
I've built one repro using 4 M27C801 and the other one using 2 M27C160, but I think it hasn't nothing to do with all this trouble either...
Any ideas? Is there any way I can't trace at which opcode the game hungs using SF7?