Dumping the ROM of a GBA game by crashing it 

It is constant rate - but due to imprecisions and the desynchronization between the console's and the recording's sample rates, each byte might take a slightly different number of samples every once in a while (say 9 instead of 10). Usually this is not a problem, since it's possible to find boundaries between different bytes by seeing the changes in audio level. Even if there's a streak of several identical bytes, it's still possible to get correct answers quite reliably just by rounding (if there's a segment of 48 identical samples, it's fine to reason that it corresponds to 5 identical bytes). However, if the streak is thousands of bytes long, the errors add up to the point where simple rounding cannot give a correct result, and it becomes close to impossible to know how many errors occurred. The only real solution would be to increase the sample rate to make the errors even less significant - but we quickly get to the point where we pretty much need a data-logging oscilloscope, and I wanted to stick to simple hardware.

​@@TheZZAZZGlitchassuming there are slight differences on each generated rom, why dont you make the program repeat several times to enhance accuracy? make 5-6 roms and keep the closest one

@@pablo5425 That's... kind of what he did? Repeat the process a few times to iron out the errors?

@@TheZZAZZGlitch thanks for your answer, this was something i was wondering as well. the fact that a byte can be represented with a varying number of samples helps this make a lot more sense.

Can you use the "average" samples per 100k bytes during periods of activity, to produce a high-precision estimate of the byte rate to bridge long gaps of silence, or does the playback and recording rate drift enough to break that? Also how did you avoid least significant bit errors?

I get it but ew

Lol 😆

Hahahahahahahaha

I was just about to mention it.

throwing up violently 45 times

i crashed my gba and at 1 hour and 17 minutes i started hearing all the sfx and its hilarious

When it's 6 A.M in a animatronic restaurant 1:11

I'm wondering what the hell the sound at 1:02 was from. Don't think I have ever heard it in-game and it doesn't really sound like it even belongs in a Pokémon game.

@@K9V1I'm guessing that they may have had a library of sounds they were working with and not all of them were used.

@@sarougeau That would actually make a great deal of sense. Very interesting sound bit nevertheless!

Thats exactly what I was wondering too. Why change the message, and not just nuke the check?

My guess is that the bootleggers were under deadline pressure - nuking the check would have taken longer to implement and debug than simply changing the message to something innocuous.

I don't really understand why anyone would have gone to all that extra trouble to make a replica cart to begin with?

@@LupisLight So they can mass-produce it and sell the carts for cheaper than the price of a real cart, of course.

Keep in mind that there's a decompilation of Emerald out there so technically they may actually have more control. The question is whether or not this repro supports the link cable and the GBA-GC cable, plus GBA-to-DS migration of Pokemon.

fact

listen to some master boot record and report back to me (this comment used to say something different)

Yea

Crazy thing is, I got this video recommended a few minutes later after I watched the interesting things 4 video. Your a mad man is all I can say.

A link got posted on twitter a few hours ago as well

Or write a program and save it on a cassette using a tape recorder peripheral. Thanks, Texas Instruments, for letting me save TI Basic that way and use it to play music otherwise!

I was thinking of the ZX Spectrum.

what???????????/

@@gabrielv.4358The C64 and other computers of the time had analog input/output, along with built-in software to save data as audio and vice-versa. Given that most computers of the time used cassettes, this was required to make full use out of them.

you aren't though

If I think of the correct bootlegs, then they patched the games to store the savefile within the same internal area where the rom is. Yes, they *write* to the *read only memory* , which is illegal.(And this is legit, patches to replicate these roms actually exist publically. Probably useful for physical repros of Gen1/2 games too because those guys normally require battery and die when it does) Idk if they also did other modifications, but nonsense like this is probably why the slightest variance in functionality from the DS makes the game cr*p itself and panicwipe the savedata. As for the elite 4-wipe in emerald, they probably just screwed up the savewrite there considering getting into the hall of fame alters specific values in your savefile that otherwise aren't touched. Either that or the way it resets the game does something to the game that this specific bootleg does not like.

It because there's actually extra space in the savefile for the hall of fame data, and writing the first hall of fame to your savefile is usually when the flag gets checked that you beaten the game and can trade pokemon outside of the regional dex. However, most bootlegs don't bother taking this into account and what ends up happening is your save will get overwritten with the hall of fame information and corrupts the save. The gen 3 games also holds two copies of your save (128k), but the bootlegs only holds one copy (64k)

Same for me, but with a bootleg version of Sapphire and Leafgreen. Sometimes, with the latter, the save file would be wiped for no reason when booting up, so in order to play through the game, I had to keep the power on my GBA. Those bootleg versions don‘t work if you use Pal Park in the Gen 4 games. Luckily, the Pokémon can be traded to a legit copy, in my case, Emerald, and get them to the most recent games.

thats actually what i did years later when i finally got legit copies. managed to transfer up a few things to gen 4, but most of the bootlegs had already wiped themselves by then anyway (or the cartridge wouldnt read at all)@@DennisTheZZZ

I had a bootleg leafgreen that worked in my DS but if I played a DS Pokemon game with it plugged in the save corrupted. Apparently that's a common issue with fakes

The data is just a little too fragile to be sent in audio form over radio. Distortions from static will probably corrupt too much of the ROM to boot it, let alone play it. But if you're interested in the general concept of smuggling information by sending it in a nonstandard format, search up "illegal numbers" on Wikipedia, you might find it a fun read.

Some pirates on shortwave kinda do, in various digital modes, mostly sstv pictures.

I've been looking to get my radio ham licence, but given that it isn't music I think I could get away with sending this sort of data over the radio, so long as I also send my callsign every now and then. It'd be fun to try, just stick a Spectrum into the radio and see how wrong it gets the data.

jet set radio:

You're not black

Holy moly, it's Camellia 👋 (Please do not add that to your latest tracks, our ears will bleed)

camellia don't listen to -w- it would be so funny if you put the gba crash sound in a song

Hello 2025 leak

gba crash remix

This ended up producing an actual game at the end though. Due to the way the Neutral Zone was made, I remember that making a ROM from that became extremely difficult after a certain point.

@@Hijiri_MIRACHION Yeah, the values used for the zone was only part of the game's memory, with 1/8 bits missing and iirc only half the entries, so essentially only half the game was to be found there, and even then that was incomplete and required a lot of guesswork to make sense of. It's a bit unfortunate, because it was really interesting

I was thinking the same exact thing

I'm pretty sure the guy who coded that thing into Yar's Revenge said "It's pretty ironic that the code for drawing the neutral zone *is* the graphics of the neutral zone" lol

@@Mizu2023he has a pinned comment in that same video

It's not a new idea though. That was how games and software were recorded on cassette tapes back in the day.

@BrunodeSouzaLino Type `load ""` and hit play, go and make a cuppa, come back 5 or 10 minutes later and find it errored out and you have to adjust the azimuth of your tape player again. Given how finicky the GBA software is here about timing, its a wonder tape loading even worked at all with the wow and flutter. I suppose the answer is a lot of error correction, but it was never perfect even with that.

You can also just import the ROM into Audacity as Signed 8-Bit Audio and a sample rate of somewhere around 10kHz to 16kHz

fyi he works at microsoft iirc so hes pretty professional

@@kab43proof?

it's in one of his april fools videos i think, he talks about being busy cause of the job iirc@@serraramayfield9230

i'm willing to forgive... around half of what you've done for being a ZZAZZ fan

Why is that so interesting

@@MasDouc These things are made for a quick buck, so to see the bootleggers put in all that effort is interesting.

If you haven't seen it, he goes over /why/ the noise happens in his previous video (Interesting observations #4). It's apparently different for every game, too, the same video has a sample of Mystery Dungeon crash sound in the section about its glitch dungeons. Super cool stuff.

In modern computing, there's no difference between software and data. The different sounds you hear are data being interpreted as audio and playing as such.

the audio chip plays samples from a pointer to a memory location that gets incremented automatically. To loop the sample you just set the pointer back to the beginning, but if the game crashes, the pointer will keep incrementing, playing every byte of memory as if it was sample data.

I'm only in the comments to say the same think. God damn I loved Uplink.

UPLINK BOIIIS

Probably because they were too rushed to test if that'd break anything, and didn't want to risk yoloing it.

I DO own one, and working in a game store I tend to use it to flash over those carts for various purposes, I usually dump them beforehand just for safe keeping.

Kid me assumed, through child moon logic, that the screech must have been Jirachi's cry. Since I knew about Jirachi but had never seen one in-game, and didn't know what it sounded like. So I wasn't *technically* wrong either :'D

Had similar thoughts after once getting weird text to pop up in SF2 CE on Genesis after accidentally bumping the console while playing. Never happened again though. Kinda wish I had a GBA game crash while I was away (on the DS due to batteries) and to come back while it was playing the instruments.

Technically, no, it's not the first time. When ZZAZZ wants to show footage from 3DS VC, he simply puts his 3DS in front of a camera, presumably because there aren't a lot of options for 3DS capture cards.

ZZAZZ also had a video demoing some Game Boy Camera emulation they worked on, by using a webcam for what the emulated camera sees.

as someone who has watched all of the video, this is a ZZAZZ classic

This is indeed a certified ZZAZZ classic.

@@kittrzfr

Meanwhile on mobile: guess they just don't want people to read it /shrug

@@renakunisaki RIP :( sorry

also, fun fact: those horrible squawking sounds after the Bard's "A E I O U" voice samples are actually compressed audio data for all the Pokémon cries! that's why they still sound slightly more like actual audio than the other glitchy screeching sounds

No there's an NPC in the game named "the bard" that uses them. He's in the mauville Pokemon center but only on certain save files.

@@iacon0425 I spent a few hours getting a save file with him because I've never had him before. The samples sound a lot different in game, are they processed somehow? I want to know more about the bard because I had never seen him before today lol

@@Zichqec He appears based on your trainer id, if it ends in 0 or 1 he will appear.

@@Tyranitar66501 Yeah I found that out, and reset over and over until I got one. And then I found out you can't mix records until you get to mauville anyways, so I had to spend a few hours making my way there. I was hoping to cheat the system by mixing records before then with a save that was already at mauville lol

👀

this is such a cool concept tho

Every song in a game using the Sappy/M4A engine has a BPM attached to it. MOTHER 3 does stuff to check whether you've pressed A to the beat, the ROM does not "tune" the soundfont.

The ‘Ah Ee Oo Ei Ou Nn’ instruments are used for the guy in one of the Pokémon Centers who can “sing” a phrase you give him! I have absolutely zero clue about the voices at 1:02 though

I wonder if the GBA has that sample recording due to something... I wonder if the GBA uses MIDI or supports it? Many keyboards, music softwares, or any MIDI-related music thing tool, mostly no matter what brand, have a choir instrument, and sometimes a female voice and a male voice. I'm still unsure what this is, though, too. (or maybe it could be WAV samples!)