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I made a short test run of Ultimate Mortal Kombat 3, but it desyncs with seconds. The desync is random, so I'm guessing this is another SPC700 related desync given how many audio samples this game uses. Definitely not worth trying to resync the play around TAS.
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I made a test run of Super Mario Kart that plays through all cups and unlocks 150cc, but when I played it back on console, it desynced on Vanilla Lake in Star Cup. It would be pretty unusual to get this far and then desync if a sound chip desync was to blame, so I suspected it might be an emulation issue.
So I then made a TAS of just Star Cup, and indeed it desyncs on console at Vanilla lake 1, seemingly deterministically.
https://tasvideos.org/UserFiles/Info/637838147769544788Link to video
I also made a time trial TAS of Vanilla Lake 1, but that synced, so my guess is that ice physics combined with all the CPU work of controlling cpu players and items etc is too much and exposes some DSP1b timing error.
I opened an issue for this in Ares Emulator github.
So, that's another dead end. Expansion chip timings seem to need some work in general.
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I did consider ending input early on the last level, but I tried by hand for a bit to to get the '9' to appear in the right place after getting the '8' without success. Basic Bot doesn't have a way to turn off input after a certain point while continuing to run, so I would need to make a custom LUA script for it, which I didn't feel like doing. NESHawk is pretty slow for that type of heavy luck manipulation across many frames, so such a script would probably have to run for a very long time. I'm not that interested, getting the '9' as quick as possible is good enough for me.
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Well it turns out that game had an improvement, but I think that kind of scenario is still something that could plausibly happen and should be accounted for.
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EZGames69 wrote:
The current publication ends input on the name entry for the final score results, where as this movie just ends it on the final boss hit.
Should this be changed to match ending input with the publication? Or should it be left as it is?
I prefer to leave it as is. I don't think it adds anything, and the game doesn't even have a battery or on board WRAM, so your score doesn't actually get saved.
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Game: Mega Man X2 (USA)
Emulator: BizHawk: 2.8 - BSNES 115 core
Console Verification Device: TAStm32 V3
Movie:https://tasvideos.org/UserFiles/Info/637833290115102148
Description of Desync: Initially desyncs because it requires 2 blank frames to get past the title screen (other SNES games require 0.) Then desyncs due to not performing a dash after jumping down into the stage. On emulator X beats the intro stage. Also gets incorrect RNG, does not seem deterministic.
Research: NES games also occasionally need extra blanks and I'm pretty sure there it's a bot issue, but what is triggering the polls? Shouldn't desync non-deterministically either way though.
Possible Next Steps: Testing with a different bot might help.
Status: Open
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I did a short test with Super Mario Kart and got some good results:
https://tasvideos.org/UserFiles/Info/637833028188202675Link to video
I learned a few things making this test. The first is that the 'no entropy' setting doesn't give correct results for this game, as it starts with 2P selected, but I tried many times on console and it always starts with 1P selected. So this movie uses 'low entropy.'
The second is that leaving the SNES plugged in seems to preserve SRAM state on the cart even with the battery removed. When I run the movie multiple times, the selected character is saved from the previous run after power cycle.
Maybe I'll make a test run that unlocks 150cc and see if it works on console.
EDIT: made a movie that unlocks 150cc, but it desyncs in star cup on console, still checking if it's deterministic and what the cause might be.
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CasualPokePlayer wrote:
Going through this movie, it seems to be very well optimized, and a solid improvement. There is one minor odd thing however. You can clear the first screen of the title sequence 20 frames sooner. Doing this in the movie through causes it to desync from general RNG difference. This seems like a rather long wait for some sort of RNG manipulation, so I'm wondering what was exactly aimed here, or if this was actually just a mistake.
It's to control the spawn point of the third pearl in level 2 while still getting good mushroom RNG. You can't effect the spawn location of the pearl after the level starts, so you have to set everything up ahead of time. I did this by varying the start presses (which controls the pearl spawn), and then seeing if I could get good mushroom RNG by varying movement right at the start of level 2. The big delay at the start is the best I could get so that everything works.
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Game: Mega Man X3 (USA)
Emulator: BizHawk: 2.8 - BSNES 115 core
Console Verification Device: TAStm32 V3
Movie:https://tasvideos.org/UserFiles/Info/637831474705110410
Description of Desync: On emulator, Zero climbs 2 ladders moving towards a vertical climb section. On console, he instead hits an enemy at the base of the first ladder. This appears to be deterministic.
Research: Most other desyncs I have encountered on SNES are non-deterministic, so it's unusual to find a deterministic one. Could be a emulation issue, possibly Cx4 chip.
Possible Next Steps: There aren't any Cx4 specific tests. Eliminating this as a source of error would probably be the first step.
Status: Open
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Bumping this thread as I am currently working on NESnake 2. This run is essentially all luck manipulation, but must be done from scratch to work on console. The end result will be the same length but with entirely different inputs. I have console verified the first level:
EDIT: new run made, video removed
I think a finished run should obsolete the current one, even if the same length.
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I've done a couple tests with zero initial RAM state (instead of the 0x00 and 0xFF pattern) and the results are promising.
Time Lord syncs no problem with no RAM clearing, which I'm very happy about as that is the game I most wanted to see verified and it didn't work with the clearing cart attempts. I put the video in the submission.
I also tried a Where's Waldo test run. This game also always desynced with the clearing cart, but worked right away no clearing needed with 0 initial state.
Link to video
Eventually I'll have a way to read out power on RAM, but it's starting to seem like 0 is the way to go.
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I console verified a version of this run that uses zero initial RAM state instead of the usual pattern:
EDIT: (encode added to submission)
As this is console verified accurate, I would like to replace the movie file with this one (it's also a few frames faster):
https://github.com/alyosha-tas/NES_replay_files/blob/main/bk2_files/link7777-timelord_0.bk2
(It wouldn't let me upload to move file for some reason.)
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Yes, VBA-rr should no longer be accepted.
But, the same also goes for most older versions of BizHawk, and lsnes, if accuracy is the main deciding factor. Especially with 2.8, it seems time to deprecate most older BizHawk releases (and not just for GB/C.)
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Making an update here now that BizHawk 2.8 is out.
NES: Most games that use the USA version and start from power on (and don't use resets) should work on console now. This includes series like Ninja Turtles, Mega Man, and Castlevania. Existing runs of these games don't sync, so a lot of new verifications are blocked just by not having runs to work with. An increasing list of games poll input in unexpected ways that the TAStm32 handles poorly. Not a major issue but something to be aware of. There are still a couple of edge cases of DMC side effects that aren't emulated properly, but I need test ROMs and haven't encountered any games that would potentially encounter them yet, so its not a priority right now (plus it would be a huge rewrite of the CPU core.) Strictly speaking the Famicom also has some effects that aren't emulated correctly yet, but I don't have a Famicom. I guess you can just use a cartridge adapter and a regular NES though.
SNES: Thanks to Morilli, poll based dumping is now possible from BNSES115. This brings SNES verification onto BizHawk. I have already verified some runs of Super Mario All Stars. Unfortunately most other runs randomly desync after some time, consistent with SPC700 issues. I am hesitant to put more time into resyncing runs when the probability of non-deterministic desyncs is high. I'll probably wait to see results of TASbot folks clock adjustment hardware work. Also some tests with Mega Man X 2/3 actually give consistent desyncs early in gameplay. This makes me think Cx4 timing may not be correct. But there don't appear to be any timing tests, and even if there were BSNES115 doesn't seem to like running homebrew with extra chips. Also I don't have a Cx4 dev board, so I couldn't compare to my particular SNES anyway.
N64: Thanks to the heroic work of CasualPokePlayer, we now have Ares64 in BizHawk. I don't know much about this core, or how accurate it is compared to Mupen, but it does use a better graphics backend, so I'm at least somewhat hopeful. I might dig out my N64 and see how thing shake out.
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I did some very short test runs of Mega Man X 2 and 3, but both desync within about a minute into the game. Pretty disappointing. Not sure what to suspect here, could be SPC700 or maybe Cx4 isn't emulated 100% correctly.
I got Mario 2 in Mario All Stars working a little while ago, so that's something:
Link to video
I'm now pretty much out of stuff to test here. A lot of runs having inconsistent desyncs seems consistent with previous SNES work. Both the console and emulator sides of the SNES are basically black boxes to me, so I don't really have a clear path forward for now. Back to the drawing board.
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Sure thing:
https://tasvideos.org/UserFiles/Info/637802689791802996
Note that the game is also impacted by uninitialized RAM, so may still desync, but I was only able to get immediate desyncs and it should work for at least a minute or two.
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Lode Runner:
Link to video
It took a bit of resyncing in terms of when to start levels, but all the game play is the same.
I also resynced 3-D world runner, but that game polls input in a crazy way (dozens of times per frame, all over the place) and the bot can't keep up.
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Link to video
Top Gun. And with that, I am out of runs to try. It's unfortunate that most of the more interesting games have runs that desync pretty badly. I have tried resyncing Mega Man 6, Ninja Turtles 1 and 3, Castlevania 2, and Blaster Master, and they appear to be pretty hopeless, new runs needed.
I have a few other games left I could possibly verify if I can get syncing runs for them, but nothing that looks like it would be too interesting or insightful. I'll still try though.
I think development is mostly complete here anyway, I'll probably try to find something new to do.
