In 2008, inichi demonstrated the full extent of subframe reset abuse in Chrono Trigger.
When Ersnes Rerecod Van Daaz Octava Deltius graced the land with his presence on the tenth of May, men fell to their knees as calamity brewed in the north.
Divine wrath descended upon a distant tundra. Thunder raged for several hours and the ground was carved anew. Soon the gods' message had reached even the farthest of lands:

"- Mid-frame reset support"

primary10bit444

  • Heavy glitch abuse
  • Uses sub-frame resets
  • Corrups save data
  • Demonstrates the glory of lsnes
Chrono Trigger (U) [!].sfc
md5sum:    a2bc447961e52fd2227baed164f729dc                                  Chrono Trigger (U) [!].sfc
sha1sum:   de5822f4f2f7a55acb8926d4c0eaa63d5d989312                          Chrono Trigger (U) [!].sfc
sha256sum: 06d1c2b06b716052c5596aaa0c2e5632a027fee1a9a28439e509f813c30829a9  Chrono Trigger (U) [!].sfc

Tricks and glitches

Loading corrupted save data

The game writes hash checksums upon saving; if the checksums don't match, the save(s) will be unloadable and displayed as empty.
Howewer, due to an oversight, it is possible to bypass this check and load corrupted save data by pressing Up+A on the save load screen.

Detailed commentary

Millennia Fair

Marle is picked up. If the Imp's house is entered without her in the party, the game will crash.

Zenan Bridge R1

The game is saved twice to set up save corruption at a later time.

Guardia Continent, Eastern Nebula

The position value 1F3E is partially overwritten with the party's current position, 4A50, resulting in the position 4A3E being stored in SRAM.

Guardia Continent, Imp's House

If Marle isn't in the party when entering this area, the game will crash.

The End of Time

The game is saved on a save point, resulting in the corresponding flag being set in SRAM. The subframe reset here is just for show - allowing the save to complete would yield equivalent results.

Zenan Bridge R2

The Zenan Bridge save is loaded. The game is then saved over the End of Time save and interrupted after the location values are written but before the save point flag is removed. This allows us to save anywhere.

Zenan Bridge R3

The game is saved on Zenan Bridge, resulting in a save file with a location value of 2000. We then exit the area and reset while the location value F001 is being written to the save file, resulting in SRAM containing the location F000.

Nu Ending

The location value F000 corresponds to the Nu ending, so the run ends when the save is loaded. Since triggering the ending in this manner wasn't intended, glitched graphics are briefly shown.

Special thanks to

  • inichi: for demonstrating the concept and making the extremely fabulous published runs.
  • Ilari: for making lsnes and helping with emulator usage and Lua scripting.

About obsoletions

The published any% and NG+ movies both abuse save corruption. This run is faster than both; obsoleting both of them seems to make the most sense.

Suggested screenshots

TBA

Nach: Reje... er... Judging.

turska: Replaced movie file. The new movie file is 46 frames faster.

turska: Replaced movie file once more. The new movie file is 12 frames faster.

Nach: I had a lot to consider in judging this run, the acceptability, the entertainment, the star issue, single or double obsoletion, and so on.
This run is clearly faster, made with a better emulator, and more real than the last run. Under these conditions, this run should be accepted to obsolete the current normal run. However this run is nowhere near as entertaining, so should it still obsolete it or not?
I watched the previous run a few times, my first reaction upon seeing it was that it was amazing and very entertaining, the second time was quite interesting too. On a third watch however, I found that the novelty wore off and the run wasn't all that entertaining. Since both these runs are about abusing SRAM, I'm accepting this run to obsolete the previous run, however, since there is very little entertainment in this run compared to the previous, it should be published without a star, a moon would be fine though.
Regarding the New Game+ obsoletion, I've mulled over it for a few days. It is loaded with a very pre-abused SRAM file. Technically, this current run here can also be loaded with a pre-abused file and cut the time down to mere few seconds. I find that pre-abusing a file sort of misses out on the point, and really is not deserving of a record. Since the main point of NG+ is to either show off new things in the game that can't be accessed otherwise, or beat the game significantly faster thanks to higher stats at the start, and the current NG+ run doesn't do the former, and it loses for the latter, I'm accepting this run to obsolete the NG+ as well.
Despite this double obsoletion for an abusing SRAM category, I think this site deserves a non abused version of CT and CT NG+, and I hope TASers will try to fill in these categories.


Senior Moderator
Joined: 8/4/2005
Posts: 5777
Location: Away
Low glitch runs particularly avoid certain bugs, rather than doing them differently to achieve other results. Inichi's test run is technically "low glitch".
Warp wrote:
Edit: I think I understand now: It's my avatar, isn't it? It makes me look angry.
Former player
Joined: 6/30/2010
Posts: 1107
Location: Zurich, Switzerland
jlun2 wrote:
andypanther wrote:
But please, don't start a "corrupts save data, but only mildly" type of run. Either use a specific trick to the max, or don't use it at all.
You mean like a "low glitch" run?
Like I said, I have no problem with banning a certain glitch for creating a different category for a game. You can call that "low glitch", although I find this sounding somewhat vague. There are tags like "forgoes time saving damage" or "forgoes save data corruption" which are very clear. "low glitch" seems to be used primarily on runs, that don't fall under any of the other restrictions, like the "no zips" run of Sonic. Maybe it should be called "forgoes specific glitches" or something like that. But a run that does use, for example save corruption, but does this in a suboptimal way, how would you categorize that?
Current project: Gex 3 any% Paused: Gex 64 any% There are no N64 emulators. Just SM64 emulators with hacky support for all the other games.
Editor, Expert player (2477)
Joined: 4/8/2005
Posts: 1573
Location: Gone for a year, just for varietyyyyyyyyy!!
andypanther wrote:
But a run that does use, for example save corruption, but does this in a suboptimal way, how would you categorize that?
Playaround?
Former player
Joined: 6/30/2010
Posts: 1107
Location: Zurich, Switzerland
Aqfaq wrote:
andypanther wrote:
But a run that does use, for example save corruption, but does this in a suboptimal way, how would you categorize that?
Playaround?
Playaround is a category in it's own, thats true. A run that doesn't aim for speed but to show of tricks. any% wich bans a specific glitch = "low glitch" or any of the "forgoes..." -categories. Fun-TAS that doesn't aim for speed = Playaround Do we really want to keep the old run published and re-label it as a playaround? That wouldn't be a playaround, just a suboptimal run, because it does aim for fastest completition.
Current project: Gex 3 any% Paused: Gex 64 any% There are no N64 emulators. Just SM64 emulators with hacky support for all the other games.
Joined: 11/17/2005
Posts: 278
Location: Massachusetts, USA
That's really disappointing to hear that Inichi's run doesn't technically work. It's like learning the truth about the tooth fairy. I voted yes because I appreciate the technical achievement. Inichi's run was way more entertaining, but if it doesn't work without 2-frame saves, then oh well. We have to go with the valid run. Also, I approve of listing Inichi as a co-author. As I remember it he basically said "When sub-frame resets exist, this is how you do it." And it's been done pretty much to his specifications. I think the "problem" with these credits-only runs is that it doesn't really feel like the game was conquered. In a lot of modern games you can view the credits straight from the title screen. The problem should be fixed by choosing better goals. Rather than "fastest time to credits" the goal should be to begin the final battle and reduce the boss to 0 hp instead. Or save the princess. Or skip to the last level and beat that. Inichi's 22 minute run beat Lavos, but this one doesn't.
Joined: 2/14/2012
Posts: 73
Catastrophe wrote:
I think the "problem" with these credits-only runs is that it doesn't really feel like the game was conquered. In a lot of modern games you can view the credits straight from the title screen. The problem should be fixed by choosing better goals. Rather than "fastest time to credits" the goal should be to begin the final battle and reduce the boss to 0 hp instead. Or save the princess. Or skip to the last level and beat that. Inichi's 22 minute run beat Lavos, but this one doesn't.
This is the main reason that I'm glad the Earthbound runs remained separate branches. The short super-glitchy run with the hidden debug menu is awesome, but the longer run actually saves the world (while still taking some major shortcuts)
Joined: 11/15/2009
Posts: 12
I vote "meh" because I don't think it's possible to reset mid-frame on an actual SNES... (I could be wrong, but I dunno) Also, I liked the current run more because it explored more of what happens in the game with a corrupted save, rather than just getting to the ending credits as fast as electronically possible. (as opposed to humanly possible)
Senior Moderator
Joined: 8/4/2005
Posts: 5777
Location: Away
GregW17 wrote:
I vote "meh" because I don't think it's possible to reset mid-frame on an actual SNES... (I could be wrong, but I dunno)
moozooh wrote:
any keypress, reset or otherwise, happens mid-frame on the actual console.
Warp wrote:
Edit: I think I understand now: It's my avatar, isn't it? It makes me look angry.
Editor, Active player (297)
Joined: 3/8/2004
Posts: 7469
Location: Arzareth
Clinical execution. Does what's supposed to. Only mildly entertaining. Is faster than previous submission, for what it's worth. Voting "meh".
Joined: 12/6/2008
Posts: 1193
Derakon wrote:
Regarding the run itself, I have to say this didn't look very different at all from the run inichi made back then. I think it's entirely reasonable to list him as a coauthor; he deserves credit for figuring out the strategy even if none of his input survives in the finished version.
Since when do we give co-authorship for ideas? Usually we give that for actual input. If we are going to start giving it for ideas I want one for the MM TAS imediatly. ;p
Editor, Expert player (2477)
Joined: 4/8/2005
Posts: 1573
Location: Gone for a year, just for varietyyyyyyyyy!!
Slowking wrote:
Since when do we give co-authorship for ideas? Usually we give that for actual input.
Since 2007-02-04, when I credited stanski for an idea. I regret for not giving more co-authorship statuses for ideas. Many would have deserved them.
Joined: 5/11/2012
Posts: 3
I found the run very entertaining and I'm glad to see inichi credited as deserved.
Emulator Coder
Joined: 3/9/2004
Posts: 4588
Location: In his lab studying psychology to find new ways to torture TASers and forumers
I'm looking for a bit of clarification here before I render my decision. Does the existing NG+ run actually corrupt the SRAM during the course of the run? Or was the corrupted SRAM created for the run and the run just uses it?
Warning: Opinions expressed by Nach or others in this post do not necessarily reflect the views, opinions, or position of Nach himself on the matter(s) being discussed therein.
Joined: 4/3/2005
Posts: 575
Location: Spain
If I recall correctly, the NG+ starts from a save, from a test run done for that purpose, in which the TASer had maximized everything (stats and items are kept in NG+ mode) In a NG+ run, you can travel directly to Lavos and fight him, hence why the movie can be finished so fast. I don't remember it corrupting the SRAM, but it's easy to test, as that requires resetting the game and watching the pendulum from the intro.
No.
Banned User
Joined: 3/10/2004
Posts: 7698
Location: Finland
Aqfaq wrote:
Slowking wrote:
Since when do we give co-authorship for ideas? Usually we give that for actual input.
Since 2007-02-04, when I credited stanski for an idea. I regret for not giving more co-authorship statuses for ideas. Many would have deserved them.
How does it work? If I point out to someone that they could save a few frames by doing this instead of that, do I deserve co-autorship?
Joined: 7/2/2007
Posts: 3960
It's presumably up to the person who submits the run; I'd imagine everyone has their own standards for when to put a contribution in the "thanks to" section and when to list them as a coauthor. Regarding the NG+ TAS, it looks like what inichi basically did was: * Unequip the Bronze Fist weapon from Ayla in his "seed" run (used to generate the NG+ file) * Glitch starting the NG+ game so that Chrono and Marle can equip the Bronze Fist * Proceed to walk all over Lavos Unequipping the Bronze Fist requires a simultaneous-input glitch (much like using the Murder Beam in Super Metroid). So save data is never modified, but it is loaded improperly.
Pyrel - an open-source rewrite of the Angband roguelike game in Python.
Emulator Coder
Joined: 3/9/2004
Posts: 4588
Location: In his lab studying psychology to find new ways to torture TASers and forumers
Thanks for the input.
Warning: Opinions expressed by Nach or others in this post do not necessarily reflect the views, opinions, or position of Nach himself on the matter(s) being discussed therein.
Post subject: Movie published
TASVideoAgent
They/Them
Moderator
Joined: 8/3/2004
Posts: 15543
Location: 127.0.0.1
This movie has been published. The posts before this message apply to the submission, and posts after this message apply to the published movie. ---- [2047] SNES Chrono Trigger "save glitch" by turska & inichi in 03:28.06
Editor, Experienced player (569)
Joined: 11/8/2010
Posts: 4035
I really like your judging decision, Nach. You explained the situation well and gave clear reasons for the double obsoletion.
Experienced player (675)
Joined: 2/5/2012
Posts: 1786
Location: Brasil
hiya,do you guys really want that submission pic?people might not recognize the game instantly,even though it shows how glitchy the run is.Maybe a normal pic is more representative.
TAS i'm interested: Megaman series, specially the RPGs! Where is the mmbn1 all chips TAS we deserve? Where is the Command Mission TAS? i'm slowly moving away from TASing fighting games for speed, maybe it's time to start finding some entertainment value in TASing.
Editor, Expert player (2072)
Joined: 6/15/2005
Posts: 3282
grassini wrote:
hiya,do you guys really want that submission pic?people might not recognize the game instantly,even though it shows how glitchy the run is.Maybe a normal pic is more representative.
Well, when we have screenshots like this for Rockman & Forte, then why not?
Experienced player (675)
Joined: 2/5/2012
Posts: 1786
Location: Brasil
FractalFusion wrote:
grassini wrote:
hiya,do you guys really want that submission pic?people might not recognize the game instantly,even though it shows how glitchy the run is.Maybe a normal pic is more representative.
Well, when we have screenshots like this for Rockman & Forte, then why not?
i saw that,and i thought that this one was good because it had the character on it,but ok.
TAS i'm interested: Megaman series, specially the RPGs! Where is the mmbn1 all chips TAS we deserve? Where is the Command Mission TAS? i'm slowly moving away from TASing fighting games for speed, maybe it's time to start finding some entertainment value in TASing.
Emulator Coder
Joined: 3/9/2004
Posts: 4588
Location: In his lab studying psychology to find new ways to torture TASers and forumers
CoolKirby wrote:
I really like your judging decision, Nach. You explained the situation well and gave clear reasons for the double obsoletion.
Why thank you! :) Let me in turn thank you for your feedback in the thread for many movies I've judged as of late.
Warning: Opinions expressed by Nach or others in this post do not necessarily reflect the views, opinions, or position of Nach himself on the matter(s) being discussed therein.
Joined: 5/27/2012
Posts: 70
Location: Wisconsin
I liked this run but aside from basically killing the game it was too short and way too glitchy for my taste, i wonder if this works on the (J) version of the game as well if not to make it faster ?
Emulator Coder
Joined: 3/9/2004
Posts: 4588
Location: In his lab studying psychology to find new ways to torture TASers and forumers
supersonicjc wrote:
I liked this run but aside from basically killing the game it was too short and way too glitchy for my taste, i wonder if this works on the (J) version of the game as well if not to make it faster ?
As adelikat already explained above, switching regions is not considered faster by our judges.
Warning: Opinions expressed by Nach or others in this post do not necessarily reflect the views, opinions, or position of Nach himself on the matter(s) being discussed therein.