The Easy Way To Encounter Aerodactyl Missingno.s (with VBA) - Page 1
This method is hit-or-miss, but I'd say you have a 1 in 3 chance of it working.
1. In VBA, go to line 3906.
2. Change "AF" to "9F".
3. Now this is where it gets tricky. There are two routines you can go through to encounter a glitch Pokemon.
a. In Oak's lab, inspect various objects around the room (preferably the third Pokeball that neither you nor your rival took) using the A button. Looking at the bookcases behind the table also works. If you do this correctly, when you attempt to move, you will enter into a battle with a Level 183 Aerodactyl Missingno.
b. Once you've gotten your Pokemon and taken care of all that business, enter into a battle right outside of Pallet Town. As soon as the screen starts flashing, hit whatever key you have set up as your A button repeatedly. If this works right, you will encounter a Level 183 Aerodactyl Missingno with a horizontally-flipped sprite.
I've found that Routine B is more reliable (in fact, it worked in 2 out of 3 battles for me just last night), but your mileage may vary.
Have fun, and don't be like me and freak out about it! 8)
Alternatively, you could do the Extended Mew Glitch with a special stat of 183, but that might crash the game and…isn't really easier.
Also, when you're doing this in a battle, you might encounter the following: a wild Pokemon calling out a Missingno. In this case, you can't escape or fight it, so you might as well reset.
Watch this video for an example of what I mean.
The 3906 glitches are really random and unpredictable. It's really good that you've discovered some pattern.
What makes $3906 special? :?
It alters the texts in a random way. (I just got the message "hit the enemy 27 times" to appear followed by crash) It also let you fly to glitch cave or cycling road randomly after conversations or battles.
I tried several times with method B but Missingno. didn't appear at all. Instead I got some interesting results.
1st try: I cleared Route 1's Pokemon after escaping from a Pidgey. Absolutely no Pokemon appeared in Route 1 after that, and my Pokedex is gone! When I choose to fly, the map showed up but I had to go through a bunch of conversation. Then I was flown away without choosing any options, and the game froze.
2nd try: I was teleported to the roof of the casino after fighting a Rattata. I flew back to Pallet Town, entered Route 1 and suddenly gained the ability of walking through walls for no reason after searching for wild Pokemon for a while. The game suddenly crashed.
3rd try: Teleported to casino again. This time I used Teleport and… I ended up in Glitch Cave.
4th try: The game froze after running away from a normal battle with Pidgey.
5th try: Pokedex got deleted after running away from Pidgey again. No Pokemon in Route 1 and the guy who gave me a potion disappeared. The old man in Viridian City blocked my path once again (since I had no Pokedex). Well, time to go back to Pallet Town to get another Pokedex (hoping Oak didn't remember I had taken one from him already). The potion giver was back but there was still no wild Pokemon. Oak was waiting at his default position in Pallet Town (beside my house; not in the lab) When I talked to him, he simply said "Hey wait! Don't go out!" and an exclamation mark on my head. The game crashed when I attempted to enter the lab.
I assume this is changing offset 0x3906 in RAM?
If so, the gameshark code 019f0639 should work, but not sure.
I assume this is changing offset 0x3906 in RAM?
Actually, method B produces a lot of unpredictable glitch stuff in general. I tried it in some cave during a battle with a Geodude, and it caused text lag and lots of glitchy sounds. It also got some of my Pokemon's attacks confused (for example, my Charmander used Submission, but the game recognized it as Pound).
Actually, editing any value in that area would produce "glitchy" effects as 0x0000-0x8000 is the ROM. A gameshark can't edit these values because they're ROM values loaded into the game on request. (I say "glitchy" because editing these values produce faux glitches)
I'm assuming this is R/B, so an easier way to encounter aerodactyl skeleton missingno would be to name yourself XXwXyXx where Captial X is a variable and w, y, and z can be switched around as desired and do the Old Man trick… as for Yellow, do what Bert said.
But if we're still into editing values, get into a fight and edit 0xCFD8 to B7 in R/B or edit 0xCFD7 to B7 in Yellow.
Codes for each would be
In fact, here's a whole table of Pokemon/item values and an entire book of GS codes. While that table isn't entirely up to date, you can use the GlitchDex over there in that side bar to get Pokemon values.
Which brings me to the question on why we need to crazily format and port over the gameshark code list. I'm sure there's a way to do it without someone gnawing their arm off from adding <br> after every line or making fun little section titles which can be done after the fact. And we don't need a page for each and every Pokemon in PC value or code group sections. I personally prefer the one text document I can ctrl+f through.
Most "glitch" videos on youtube are about changing the values of $3906 or $3907 to produce random glitching effects. These bytes must have some significance.
If we're talking about unlegit ways to get Aerodactyl-form Missingno., just use 01B759D0 (01B758D0 in Yellow). No need to walk and search, it just appears. Profit!
If it comes to $3906's crazy effects, some are unpredictable, while some are not. For example hex 0E always fades out the music, hex C0 always makes the screen go white, 0F always gives "Too bad! The trade was canceled!" message, while hex EF gives a nice disco effect while holding A. But hexes like 9F, 45, 3C give a lot of different results and it's hard to spot any patterns or similarities between them.
Also, has anyone gotten other forms of Missingno. than the "regular" form and Aerodactyl form when modifying 0x3906?
$3905-$3907: CALL XXYYh, where XX is $3907 (default 20) and YY is $3906 (default AF).
Changing the value of $3906 results in calling another line instead of the intended one and hence produces glitchy results.
But this line is called only if you press A or B during conversation. It normally doesn't have any effect since it is directed to HALT ($20B3). I don't know much about assembly code, however.
1st try: I got a random blue poisoned pokemon named x2 to battle a wild Rattata for me. When I pressed FIGHT, a conversation box popped up with a single 'x' character. The blue pokemon was poisoned to death before I did anything. A large blank text box popped up instead of the usual one asking me whether I should change pokemon, and the game locked up.
2nd try: I threw a pokeball before the battle even started. Yellow and green brick tiles appeared at the center of the screen, and a L192 Aerodectyl Missingno. was sent out! I didn't send out a pokemon though, and the usual "FIGHT PkMn ITEM RUN" box appeared. *saved state here*
Trial 2.1: I selected ITEM. The inventory is completely glitched, with EARTHBADGE, SOULBADGE, WATER STONE x(glitch box)2, VOLCANOBADGE, and more, but I didn't get to see the rest because OAK automatically said "(glitch box)(glitch box)(glitch box) x 2 (glitch box)(glitch box)(glitch box) x 2 (glitch box)(glitch box)(glitch box) x 2 (glitch box)(glitch box)(glitch box) x 2 … (repeated by many times, replaced the battle screen) 'r(glitch box)! This isn't the time to use that!" Okay my name was changed to that long chunk of characters. After a few loops though (I wasn't able to do anything as OAK's box kept popping up), my name was changed back to "(glitch box)(glitch box)(glitch box) x 2(glitch box)(glitch box)(glitch box) x 2(glitch box)(glitch box)(glitch box) x 'r(glitch box)", a lot shorter.
Trial 2.2: I selected PkMn. As predicted, my party was stuffed with lots of invalid Pokemon that the screen locked up.
Trial 2.3: I selected RUN. The usual "No! There's no running from a trainer battle!" box appeared. The text box persisted after the selection box reappeared.
Trial 2.4: I couldn't select FIGHT.
Conclusion of 2nd try: This Missingno. can't be fought nor escaped from.
3rd try: A comparatively "normal" wild battle with Rattata. The game froze after I ran from it.
4th try: Triggered the "Pokedex disappeared and no wild Pokemon" glitch. All overworld sprites (including mine) appeared to move in the opposite direction of the actual movement. I reached Viridian, all sprites returned to normal except mine, which appeared 4 tiles below the actual position. I logged on the PC in the Pokecenter (BILL's PC changed back to SOMEONE's PC), and the active box was BOX 1(glitch box). I deposited a Pokemon just to see what was inside the box. The box was full of Pokemon whose names consisted of 'x', '2' and glitch boxes. There were also a Pokemon (the 6th one) named RED (my name until now), 4 more randomly named glitch Pokemon (22nd to 25th), and a Mew (the 26th one) I just deposited. *saved state here*
Trial 4.1: Attempted to select an "x 2" glitch Pokemon (and the others with glitched name). Game froze.
Trial 4.2: Accessed the stat page of "RED". It was a Blastoise (my starter), poisoned and at L28.
All normal except for the current health and the OT, which was like the names of the glitch Pokemon (x 2). The ID number was also different. The moves had invalid PP and glitchy/blank names, which I suspected to be super glitch moves. The exp was also a very large number. As expected, those were super glitch moves. My name was changed to "Enemy PIDGEYPC", and the POKEMON option on the menu couldn't be selected. (indicating I had NO Pokemon at all?) I tried to find something to fight. Route 2 was blocked off by the old man; Route 1 didn't have any Pokemon. So I went to Route 22, and the game crashed.
Trial 4.3: Triggered the "super glitch effects" again, by reading the stat page of the Blastoise named RED. I checked the box again. Right. I had no Pokemon. I went all the way back to Pallet Town to find MOM to heal my non-existent Pokemon. The game crashed after the dialogue. (This means the Pokemon in your party are actually healed after the dialogue instead of during the screen flash?) Went into Blue's house. Op-code error. Into the lab. Crashed.
Trial 4.4: I tried to withdraw my Mew back. The game froze. It seemed that "SOMEONE's PC" was a black hole that stuck Pokemon into it.
Trial 4.5: Tried to change box. The game saved normally, but the selection cursor wasn't there. When I pressed A, an op-code error occurred.
Trial 4.6: Released "RED". After checking the box again, I realized that my Mew's released instead and "RED"'s name also became glitchy.
Trial 4.7: Tried releasing Mew instead. The game froze after selecting YES.
Note 1: The sprite was returned to its actual position after jumping off a ledge.
Note 2: Under this particular "super glitch" effect, the YES/NO option became NORTH/WEST in the save menu. The save file was corrupted and deleted as the name (glitch block)(glitch block)Enemy PIDGEYPC(glitch block)(glitch block) has 8 characters.
Note 3: I could never enter a battle after the glitch, as I couldn't walk anywhere from Pallet/Route 1/Viridian. FLY froze the game and TELEPORT took me to the glitch cave/Viridian. I didn't receive HM02 yet so I couldn't SURF south from Pallet.
Note 4: The items in PC were also glitched. There were TM48 and two glitch items, which I couldn't use at all. (Oak was following me everywhere, telling me not to use the items :P)
As there should be MORE glitchy effects, I'm uploading the save state here.
But this line is called only if you press A or B during conversation. It normally doesn't have any effect since it is directed to HALT ($20B3).
While modifying 3906, I've sometimes found that pressing A (or B) results in the remainder of the text being shown. Also, on occasion, all the text in a box will appear at once instead of appearing gradually.
The X2 thing is one that I've encountered multiple times. It only affects names: Pokemon and personal Trainer names, like you said, but also enemy Trainer names. I'm not sure whether Rattata (called X2 by the game, but only before calling out Missingno.) calling out Missingno would classify as a Pokemon or a trainer, but here's a video for your consideration.
The game clearly considered you in a trainer battle (you couldn't run away), but you hadn't sent out any Pokemon (so the FIGHT option was not available). Have you tried pressing ITEM?