Just out of curiosity, what are the default values of the location bytes on an empty save file?
Wouldn't they be 96, 96? SRAM filler values are always 96s, I thought. I imagine it's not a useful location, since inichi's runs haven't used this location. Probably a bunch of trees or 1999 A.D. World Map or something.
Joined: 11/17/2005
Posts: 278
Location: Massachusetts, USA
Acheron86 wrote:
RT-55J wrote:
Just out of curiosity, what are the default values of the location bytes on an empty save file?
Wouldn't they be 96, 96? SRAM filler values are always 96s, I thought. I imagine it's not a useful location, since inichi's runs haven't used this location. Probably a bunch of trees or 1999 A.D. World Map or something.
Seems like the game crashes. On snes9x 1.43 anyway. With v1.51 (which I normally use) my spacebar was refusing to work for some reason.
That could be interesting...if it doesn't just boot you to lavos.
Actually, you can use a couple Game Genie/PAR codes to get there (I don't remember them offhand but they're probably easy to find). It's kind of neat to walk around, but totally useless because there are no map triggers.
which version should I use to watch these?
part1 plays fine but the others just freeze up the game at movie start.
these are the versions I have, I tried all the 1.43 versions listed.
second smv link (-16 seconds run) points to avi
Just out of curiosity, what are the default values of the location bytes on an empty save file?
As Achelon86 said, all they are 96 (0x60). The second location byte should be 0 or 1; otherwise the game crashes as reported by Catastrophe. One thing I couldn't figure out is, though, that a bunch of memory addresses are overwritten at one time before it completely crashes. I really have no idea what causes it. Maybe it could be of some use.
For future reference, here are all memory addresses whose values are stored in SRAM in order:
7E2400-29AF
7E2C23-55
7E0400-0F
7E0100-0F
7F0000-01FF
7E027E-7F
7E0290-A0
7E2C7C-99
The location bytes are 7E0100-01; the X-Y coordinate 7E0102-03; the storyline counter 7F0000.
xPi wrote:
which version should I use to watch these?
Snes9x 1.43 v14 or any later version.
part1 plays fine but the others just freeze up the game at movie start.
All the smvs except part 1 automatically pause at start, possibly because they were recorded from between a frame. So if the freeze should be actually the pause, you can resume by just pressing the Pause key. If not, sorry, I can't help you there.
Does deleting a file bother to wipe all the saved addresses or does it just change the minimum for the menu to go "Aha, this is supposed to be an empty save" and ignore the rest until they get overwritten by a new save?
edit: I can't even remember if CT bothered having a delete option
The latter. When the save process is over, the game sums up all the values in the saved addresses and overwrites it to a checksum address.
Here are the checksum addresses:
307FF0,2u,Save file 1
307FF2,2u,Save file 2
307FF4,2u,Save file 3
When you reset the game and skip the pendulum scene, the game sums up those values again and compare it with the checksum address. If they are not equal, the save file is considered as invalid and a flag is set to make the save file appearance empty in the load screen. The game never touch the contents of the save file. It should be noted that the sum up process is done on a 16 bit mode. So if you switch items which place at an odd/even slot, say, 1st and 15th, a checksum will be still the same unless you don't save at different frames. Making use of this, you can go through the error check and duplicate an item.
Here is a demo showing how to duplicate an item without making a save file empty.
http://dehacked.2y.net/microstorage.php/info/1849726233/item_duplication.smv
In this movie, I switch the 1st item and the 3rd item and reset on the timing that item numbers aren't overwritten. In that case, the checksum is the same with what is supposed to be; consequently the game can't detect any error. Thus, I manage to duplicate an item without making a save file empty.
Also, when I was making the run, I didn't care the checksum stuff at all. The reason is that you can load an empty save file by simply pressing A and Up/Down key at one time in CT. If it had not possible, the item duplication part would have been much more complicated and bothersome.
Joined: 11/17/2005
Posts: 278
Location: Massachusetts, USA
inichi wrote:
In this movie, I switch the 1st item and the 3rd item and reset on the timing that item numbers aren't overwritten. In that case, the checksum is the same with what is supposed to be; consequently the game can't detect any error. Thus, I manage to duplicate an item without making a save file empty.
Now THAT'S interesting! :D
When you first posted the glitch that allowed you load an "empty" save by merely pressing up+A, I immediately started testing it on every other SNES rpg I could think of. Chrono Trigger was Square's last rpg on that console and I used to think it was their most 'secure'. It didn't have as many (any?) unintentional sequence breaks or memory corruption glitches. (Until it met you.) So I was surprised that no other game had this major vulnerability.
When played with a re-recording emulator, all other rpgs that I tested give you just 1 or 2 frames to corrupt your save file. Any earlier or later and the save either never happens or completes normally. (This is something that I believe is not emulated correctly. A real console lags badly while saving and the window is more like a whole second.)
I imagine it wouldn't be too much trouble to manipulate the checksum of a merged save file? I'm thinking about any game, not just Chrono Trigger. First you have to figure out if the checksum is first or last so you can plan on which save file will be bringing the checksum with it. Then you manipulate your current game state such that the merged save will have the same checksum. The most obvious thing to do is merge a new game with the blank (0x96) data. If you could start a new game, name yourself "G0hhhj", pick up a sword and 170 gold pieces, save and reset, and load a more powerful saved game, then that would be so broken we'd need a new category for it.
...but I'm working on Castlevania right now.
I'm thinking of improving the current SDA ng+ run (which is just luminaire spam, even when the boss has only a thousand health remaining), and so I went back and skimmed through this topic and watched the old ng+ tas. That was pretty helpful. For battle strategies, I'm probably going to copy it, like so:
Shell: Crit with shiva edge, slash, luminaire
Inner: Luminaire x2 for arms, then ice sword 2, luminaire x2, ice sword 1
Core: Shiva edge crit on left bit, attack right bit with marle to drop defense quickly (and thus avoid a long attack by the center bit later), luminaire x5
When I started planning for this run, I originally wanted Marle to crit inner lavos twice to deal the last 1100 damage you need after 3 luminaires, but reading this topic shows that it'd just mess up the crit tables, and casting ice sword 1 and 2 is probably just as fast as luminaire, crit x2 anyways. I'd just crit with Crono once, but that seems to let the battle go on for just long enough that Lavos casts flame battle. Oh well.
Anyways, the above shouldn't be news to you guys, for obvious reasons. I stated it mostly so you could correct me if I have the reasons incorrect. What I actually want to do, however, is ask a few questions. Namely:
-How does the menu trick work? Do you just open the menu at the specific time? What are the margins of error? I'm currently just mashing X and hoping I get it, which in addition to being galling to me personally, has the side effect of me not being able to react to it quickly if it does work.
-How do you skip inner lavos using sickles after Doors of Doom?
-Why do you want the center bit to Time Change? Would it be faster if it just used a regular attack?
And, finally, where's the fastest place to grind levels? ;)
Sorry for the late response. I have been away from the site for a while.
How does the menu trick work? Do you just open the menu at the specific time?
There is one frame window in a specific screen transition. If the X button is pressed there, you can enter the menu. Also, you don't need to mash the X button to open the menu. Instead of that, just hold down the button, and the game considers it was pressed on the right timing. It should be noted, however, that it doesn't work if you start holding down the button too early. I always start holding it down as soon as the screen goes completely dark. I'd recommend you to follow it because it is quite easy to grasp the timing.
What are the margins of error?
Once you get used to it, you can almost always reproduce it.
How do you skip inner lavos using sickles after Doors of Doom?
By changing the battle speed lower. Max speed Crono in Haste is twice as fast as Inner Lavos arms. However, the faster the battle speed is, the closer the speed gap is. Even TAS can't precede the sickles at the fastest speed. If you're having troubles with those sickles, you can try at lower speed.
The same goes for this:
I'd just crit with Crono once, but that seems to let the battle go on for just long enough that Lavos casts flame battle. Oh well.
Slash would be slightly faster than Crono's critical hit, though it may make it difficult to get another critical hit in the next fight.
Why do you want the center bit to Time Change? Would it be faster if it just used a regular attack?
No, it wouldn't be. Contrary to appearances, Time Change is faster than the regular attack.
And, finally, where's the fastest place to grind levels? ;)
As mentioned in this post, Death Peak is a good place to level up. Black Omen is also good if your characters level up enough to handle strong techniques. The four enemies in front of the room with the teleporter will give you 2500+ exps in every fight.
On a side note, I'd encourage you to try to skip the candy cutscene. Candy skip is a trick that can be reproduced not only by a tool, but also by human. The success rate is rather low; in my case, it is only once out of five times on average. However, since it will save a good 20 seconds, I think it's worth trying.
I hope these tips help you. Good luck on your run.
Thanks for replying. I had finished a run a couple weeks ago, which has just been formally accepted to SDA (the reason I remembered to check this topic) and is available here for now. The final time is 0:06:56, almost a minute faster than the current SDA run, but I guess I have to redo it now, haha.
The comments for my run are included in that zip file and are pretty descriptive, but you don't need to bother reading them. If you know what's going on in the run it's rather obvious.
About everything else:
I was not able to get the candy skip to work, so I cut it out of the run. If you can get it to work that often, however, it's definitely worth redoing my run for. I'm going to go try harder, but do you have any specific advice for it? [edit] nevermind, I managed to do it somewhat often. There's no need to explain.
I also did eventually figure out how to consistently replicate the menu trick. The TAS threw me off for a while because it only pressed the button for one frame, but I did eventually figure out how to do it, even coming to the same conclusion as you, that I needed to wait until the screen went completely dark.
For the Inner Lavos battle, I decided to have Marle use Ice 2 to deal the last 1100 damage. I chose this strategy because it requires no luck, because it makes me able to select Crono's moves faster, and because this does not require Crono to take an extra turn. In my experience, if Crono takes that extra turn, Lavos always has just enough time to use Shadow Slay. Using slash instead is an interesting idea, although that runs into the same problem as Ice Sword 1 + 2. I also hadn't expected it to make future crits more difficult; I guess I don't understand that part of the game.
Also, I took the easy way out on the Lavos Core and used Confuse on the left bit instead of a crit. I had simply given up at that point, since that crit was never happening despite repeated attempts, and the center bit was even starting to use Crying Heavens exclusively the more consistently I did the previous battles. I gave up at that point and decided that those were acceptable for the run. I've been thinking about it, however, and I'm becoming more and more convinced that an RNG seed is carried over from the previous save, and that I should go do various things on that save and keep trying to see what happens. I was certainly getting consistent enough luck in the run itself. Do you know if this could be the case? [edit] I'll be heading back home tomorrow, so when I get back I'll start trying things and seeing what happens. I put this run off for a while, but I think it's time to start making attempts again.
And, finally,
Max speed Crono in Haste is twice as fast as Inner Lavos arms. However, the faster the battle speed is, the closer the speed gap is. Even TAS can't precede the sickles at the fastest speed.
That makes me feel a lot better, as I felt bad about bumping the speed down to 2. I thought the TAS used battle speed 1, but I just went back and checked it, so I guess I wasn't paying enough attention.
Anyways, thanks for your reply. I greatly appreciate it. :)
Is there any non-New Game+ non-glitched TAS run that goes through the whole game in the works? :(
Would love to see something like that.. though it's hard to pinpoint an exact point where the game is "complete," but that can be figured out.
Would love to see something like that.. though it's hard to pinpoint an exact point where the game is "complete," but that can be figured out.
Depends on if you define it as using the expected route, or just As Fast As Possible. Expected route means no Lavos fighting until after the Undersea Palace, AFAP means as soon as you're ready, use the bucket. Or just 100%, meaning go through Undersea Palace, plus the optional quests after that.
Would love to see something like that.. though it's hard to pinpoint an exact point where the game is "complete," but that can be figured out.
Depends on if you define it as using the expected route, or just As Fast As Possible. Expected route means no Lavos fighting until after the Undersea Palace, AFAP means as soon as you're ready, use the bucket. Or just 100%, meaning go through Undersea Palace, plus the optional quests after that.
I thought something like this might be kind of neat. But everyone's definition of 100% isn't necessarily the same. I think once you can't go any further with any NPC item trades or extra boss battles it's considered 100% complete QUEST-wise. That'd be my favorite kind, eliminate that rare item grind-fest. But once again, it's subjective.
Im suprised that this hasnt picked up much interest. I find the process of resetting on half a window of game input to be very interesting. This might change a lot of things not only for Chrono Trigger, but for all TASes in general.
Is there any way that this could be further investigated & utilized for future runs?
Hello everyone,
I'm currently working on a non-memory-corruption any% TAS. I think this game deserves it and there is a lot of tricks to show. You can see my current WIP here: User movie #12673535284949127. I expect the final time to be around 2:15.
Also, I run across a series of WIPs in niconico, here is the first part:
Link to video
Title says: "I tried to beat Lavos in a minimal number of victory"
Description says: "[Caution] This video is not a speed run! I challenge the minimum number of times clear victory of Chrono Trigger that has been believed to be theoretically impossible. Without any useless battle, I will defeat Lavos at the time came to the End of Time for the first time."
:)
