Posted: 7/20/2014 5:20 PM
Post subject: Guidelines regarding uninitialised RAM
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keylie
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In ff6, the encounter increment is a 16-bit value that increases by a constant at each step. When this increment reach a threshold, a battle happens. However, this increment is not initialised by the game. It is using the value stored in the RAM when the console powers on. With snes9x (at least 1.43 and 1.51), the entire RAM is set as 0x55. With Bizhawk 1.7.2, the RAM is initialised with what is seems to be random values (but same values every time). For my example, the increment set by Bizhawk is bad (0xFDFB) and a battle is triggered after the first step. I was wondering if it was possible to set other initial values of the RAM.
Posted: 7/20/2014 5:32 PM
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natt
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It is not possible to specify initial RAM in Bizhawk SNES, other than by making a savestate-anchored movie.
Posted: 7/20/2014 5:38 PM
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adelikat
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Posted: 7/20/2014 6:17 PM
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Twisted_Eye
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My first thought is, hey, a TAS can manipulate anything else in a run, why not also manipulate the start of the run? By that I mean, if you can have the resources to peek at the memory in the first place, than you theoretically can do what it takes to set up the RAM for yourself before you start your run. How many games would benefit from this, anyway? I imagine a good chunk of games take a second to blank out the RAM before anything is read from it, or at least the parts that would get used. (Sure would be nice to have this feature for Ultima: Exodus for the NES, though, there's a glitch that can read from the untouched RAM during party creation that I would have looooved to manipulate when looking at it a couple years ago)
Posted: 7/20/2014 6:27 PM
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creaothceann
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This topic came up before (somewhere here, iirc). Personally I don't think a movie should be able to change properties of the emulated systems (unless it starts from a savestate); it should only contain input that is physically available to real players. Of course you could reset the system in a TAS though.
Posted: 7/20/2014 7:08 PM
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Warepire
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I will state now as I stated during the discussion that spawned from the Cheetahmen 2 submission. For every console where a bootstrap or BIOS doesn't initialize the RAM, setting the RAM to whatever is the most useful shall be allowed, AS LONG as that RAM state is possible on real hardware. I remember byuu writing something on his forum about some games crashing when some RAM ranges contained certain values.
Posted: 7/20/2014 7:53 PM
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zeromus
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Just to be clear: that some games crash when RAM ranges contain certain values cannot be taken as evidence that the certain values are impossible on real hardware.
Posted: 7/20/2014 7:58 PM
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Masterjun
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creaothceann wrote:
This topic came up before (somewhere here, iirc).
Was it this topic?
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Posted: 7/20/2014 7:59 PM
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Warepire
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zeromus wrote:
Just to be clear: that some games crash when RAM ranges contain certain values cannot be taken as evidence that the certain values are impossible on real hardware.
Should have been clearer on that, thanks.
Posted: 7/20/2014 8:07 PM
(Edited: 5/24/2018 12:58 PM)
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Posted: 7/20/2014 8:22 PM
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creaothceann
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Masterjun wrote:
creaothceann wrote:
This topic came up before (somewhere here, iirc).
Was it this topic?
Yes, thanks.
Posted: 7/21/2014 12:22 AM
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Pasky13
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I'm not opposed to different RAM initializations, assuming they are cherry picked from known ones from actual consoles.
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Posted: 7/21/2014 12:26 AM
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Patashu
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Pasky13 wrote:
I'm not opposed to different RAM initializations, assuming they are cherry picked from known ones from actual consoles.
If a TAS uses a certain RAM initialization, it should be fully disclosed in the description. Then users and judges can decide if 'Seems reasonable enough' or 'lol no, put the cosmic rays away'
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Posted: 7/21/2014 1:33 AM
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Pasky13
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I don't agree. At that point, runs will be allowed if a certain RAM initialization allows lots of entertainment value, at which point, you're not using a <insert_console> and you're just hacking things to hell.
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Posted: 7/21/2014 1:48 AM
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Patashu
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Pasky13 wrote:
I don't agree. At that point, runs will be allowed if a certain RAM initialization allows lots of entertainment value, at which point, you're not using a <insert_console> and you're just hacking things to hell.
But if you have to disclose all ram initialization you specified, then it'll become really obvious that it relies too much on it and people will vote 'no'
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