Guides:SRAM Glitch ACE Setups (EN Yellow)

From Glitch City Wiki
Jump to navigation Jump to search

This page serves as a repository for methods to quickly set up advanced ACE setups, starting from a fresh save file. These methods can be used for the English releases of Yellow. It is part of the TimoVM's Gen 1 ACE setups set of guides.

The methods described here were heavily inspired by previous SRAM glitch setups developed by Evie (Chickasaurus GL), as well existing setups intended to be used for the Japanese releases.

Please make sure to fully read every step of the guide before executing them.

If you encounter any issues when going through this guide or would like to provide feedback, please contact TimoVM on the Glitch City Research Institute Discord.

The contents of this guide are demonstrated in the following video:

YouTube video by TimoVM


Setting up initial ACE

When you use UP + SELECT + B on the title screen, the game will delete the save by filling the entirety of SRAM with $FF values. When you then interrupt the very first save process with specific timing, you can create a glitched save file that has a party consisting of 255 ($FF) pokémon. This is known as "SRAM glitch".

Within this glitched state, we can abuse the expanded party to affect memory areas that are normally unrelated to the party, with a wide variety of possible effects. In this guide, we will be abusing this to set up an ACE environment through the following process:

  1. Set up SRAM glitch
  2. Using SRAM glitch, access Celadon City so that we can assemble an item code that will allow us to write code using boxed pokémon's nicknames.
  3. Using an exploit known as "Map Script ACE", set up a method to quickly pick up an unlimited amount of Eevees
  4. Write code by repeatedly picking up and nicknaming Eevees. This will be used to build a program that allows you to more easily write arbitrary code.

Note: setting up ACE on an existing save

While this guide is built with new saves in mind, the method itself is inherently compatible with existing saves that fulfill the following criteria:

  • Must have reached Celadon City.
  • Must be able to use Fly and have a party pokémon that has learned Fly.
  • Must have set up the Expanded item pack. It is recommended to deposit all important items to the PC prior to setting up the expanded item pack.

Once you have all of these requirements, you can continue the guide from step 4 onward.

Step 1: Starting a new game and setting up SRAM glitch

First, we need to set up SRAM glitch.

  • Clear all saved data by pressing UP + SELECT + B on the title screen and confirming that you want to erase all saved data. (This needs to be done even if no save data is present).
  • Start up the game and go through the intro. Name your character and rival any name you want.
  • Open the start menu, and select "Save".
  • Select "Yes" in the "Yes/No" dialog box. At a very precise moment, power off or reset the console.
    • Soft resetting (holding Start+Select+A+B) will not work, as the game prevents soft resets while it is saving.
    • The timing to power off or reset is after the "Yes/No" dialog box has disappeared, but before the text changes to "Now saving..." (Red/Blue) or "Saving..." (Yellow).
      • The time window between those two visual cues is around 20 frames (depending somewhat on the version and the circumstances), but the window to successfully perform this glitch is only 4 frames.
  • Reload the game. If you can continue the game and can open the pokémon menu, you have successfully set up SRAM glitch and can continue with the guide. Otherwise, repeat the process from the start, erasing the save in the process.

A quick note on the effects of SRAM glitch

Thanks to clearing out the previous save using UP + SELECT + B, which fills saved data with $FF values, we will reload with a party consisting of 255 ($FF) pokémon. There are, however, quite a number of side effects due to this:

  • Having 255 party pokémon makes us unable to enter battle without heavy side effects. Due to this, we will be avoiding battle completely.
  • It is heavily recommended to not look at the summary of any of the party pokémon, since they are made up of glitched data.
  • Thanks to having 255 party pokémon, we are able to swap pokémon beyond the 6th party slot.
  • Every few steps, the game will act as if at least one party pokémon is poisoned. This effect can be freely ignored.

Throughout the guide, codes are provided that resolve these side effects and allow you to resume normal game progression.

A quick note regarding unterminated name items

Certain glitch items lack a proper string terminator. When you select them, either by pressing A or select when highlighting them in the bag, these items will crash the game. On the Virtual Console releases, this has a possibility of erasing your save. When you see any item with an unusually long glitched name, please make sure to not use either of these buttons to select them.

In certain maps, such as Celadon City, opening the item bag or scrolling the item bag to display an unterminated name item will cause the game to seemingly freeze. You can cause the game to safely resume by tapping b regularly until the game continues.

In the Celadon City map, unterminated name items can be made safe to handle as long as at least one tree is visible on the upper row of the map while the start screen is opened. Under these circumstances, unterminated name items can be safely selected with a or select. This will also ensure that you do not need to tap b multiple times in order to scroll through unterminated name items, but certain items may still require a single b press to scroll through.

During the guide, care is taken to ensure that we'll only stand on these safe spots when using the item bag.

Step 2: Reaching Celadon City

The main item code will be assembled in Celadon City. We will be abusing the extended party's properties to obtain an expanded item pack. The expanded item pack is a glitched state where the game thinks that we have 255 ($FF) items in the item pocket, even though the item pocket usually has a maximum size of only 20 items. This allows us to access areas of memory beyond the item pack and treat them as if they are items. We will be abusing this to warp directly to Celadon City.

Place to stand
  • Go downstairs and exit your house to Pallet Town. This registers Pallet Town as a Fly location, preventing a possible crash at a later point in the guide.
  • Go back inside your house and take a single step to the right, so you end up at the location indicated by the screenshot above.
  • Open the party menu and swap the 2nd party pokémon with the 10th pokémon. This sets the amount of pokémon caught in the pokédex to 152, as well as setting the amount of items in the bag to 255.
  • Open the item bag and scroll down to the 36th item slot. This will be a Master Ball with quantity x0 (see screenshots below). Toss a total of 250 items from it for a final quantity of 6. When tossing, you can press down to underflow the amount of items to be tossed from 0 to 255, then press down 5 more times.
  • Exit your house. Thanks to changing the item quantity, you will exit to Celadon City.
Slot #36

Step 3: Setting up a pokémon that can use Fly

In order to assemble the required item code, we need a pokémon that knows Fly and we need the necessary badge to be able to use it. We will be abusing the mechanics of the extended party and the extended inventory to add Fly to the 11th party pokémon.

Potion location
  • From where you exited out to Celadon, Walk 6 steps right, 4 steps up,6 steps right and another 4 steps up so you end up at the spot indicated by the above screenshot on the left. At this spot, the item in the 35th item slot will have turned into a Potion x0, as indicated by the below screenshots. Using Select, swap this Potion x0 to the 29th item slot. This will give you the Thunderbadge and the Soulbadge, allowing you to use both Surf and Fly. Check your trainer card, you should now have the third and fifth badges.
  • In the 39th item slot, you'll find a TM23 x64 stack. Toss 45 items from this stack until you get a TM23 x19 stack, then swap it to the 7th item slot. This will alter party pokemon #11's data and allow it to use Fly.
  • Finally, open the party menu, select the 11th party pokémon and have it use fly. Fly directly to Celadon City. If it doesn't have fly, make sure that the TM23 x19 stack is located in item slot #7.
  • (Optional) Only if you're playing on the virtual console releases, it is advised to enter the pokémon center and change the current active box any box other than box #2.

It is now safe to save the game.

Slot #35

Step 4: Assembling an item code in Celadon City

While standing in front of the Celadon City Pokémon Center, take 3 steps right, 5 steps up, 11 steps left and finally 3 steps up to reach the following spot. Make sure to bring a pokémon with Fly/Teleport.

Place to stand

While standing on this spot, open your item bag and keep scrolling down until you find a Thunderstone x0 item stack, located at item slot #35 as indicated by the below screenshot. We will use this spot to orient ourselves for the next section.

Slot #35

By walking left or right, you can increment or decrement the item ID in slot #35. By walking up and down we can alternate between an item quantity of x0 and x1. We can safely swap the contents of item slot #35 with other item slots, as long as we use Fly/Teleport afterwards to restore the map back to normal. We can use this to collect all the items we need for the item code. slot #33 will always contain a bicycle, you can safely use this to speed up the process.

For every item in the following table, head to the Thunderstone x0 spot, follow the instructions to obtain an item stack, then Fly back to Celadon and head back to the same spot to obtain the next item stack. It is heavily recommended to save after every time you fly back to the Celadon City Pokémon Center.

During the entire process, make sure to not swap two item stacks that have the same item. This will cause both item stacks to merge, resulting in glitches as side effects. When this happens, you can reset the game to restore the game back to normal.

Item location Item ID Item quantity How to acquire
Max Potion x105 At the Thunderstone spot, walk 16 steps to the left to get Max Potion x0. Toss 99 from the stack, then toss another 52 from the stack, then swap to slot #6.
Thunderstone x05 Go to the Thunderstone spot to get Thunderstone x0. Toss 251 from the stack, then swap to slot #8. (Make sure to preserve the x19 item stack in slot #7 so you can still use Fly)
TM22 x42 At the Thunderstone spot, swap the Thunderstone with the TM23 x64 stack 4 slots below, then toss 63 TM23s. Walk 1 step up and 1 step left to get TM22 x0. Toss 214 from the stack, then swap to slot #9.
Great Ball x135 At the Thunderstone spot, walk 30 steps to the left to get Great Ball x0. Toss 99 from the stack, then toss an additional 22 from the stack to reach x135, then swap to slot #10.
Antidote x48 At the Thunderstone spot, walk 22 steps to the left to get Antidote x0. Toss 208 from the stack, then swap to slot #11.
Poké Ball x134 At the Thunderstone spot, walk 29 steps to the left to get Poké Ball x0. Toss 99 from the stack, then toss an additional 23 from the stack to reach x134, then swap to slot #12.
Hyper Potion x44 At the Thunderstone spot, walk 15 steps to the left to get Hyper Potion x0. Toss 212 from the stack, then swap to slot #13.
Super Potion x32 At the Thunderstone spot, walk 14 steps to the left to get Super Potion x0. Toss 224 from the stack, then swap to slot #14.
TM44 x201 At the Thunderstone spot, swap the Thunderstone with the TM23 x64 stack 4 slots below, then toss 63 TM23s. Walk 2 steps down, 12 steps right, 5 steps down and then 9 steps right to get TM44 x0. Toss 55 from the stack, then swap to slot #15.
Calcium x243 At the Thunderstone spot, walk 6 steps to the right to get Calcium x0. Toss 13 from the stack, then swap to slot #16.
TM14 x213 At the Thunderstone spot, swap the Thunderstone with the TM23 x64 stack 4 slots below, then toss 63 TM23s. Walk 1 step up and 9 steps left to get TM14 x0. Toss 43 from the stack, then swap to slot #17.

After flying back to Celadon city, we will verify if all items have been successfully collected.

  • Before opening the bag, walk 5 steps to the right from the entrance of the pokémon center. This will ensure that we can open the item bag without issues.
  • Open the item bag and swap the TM14 x213 stack located in slot #17 to the item stack in slot #7. This will remove the ability to fly, but is required to complete the item code.
  • Next, make sure your item bag looks as follows:
Item slot Item ID Item Quantity
Slot #6 Max Potion x105
Slot #7 TM14 x213
Slot #8 Thunderstone x05
Slot #9 TM22 x42
Slot #10 Great Ball x135
Slot #11 Antidote x48
Slot #12 Poké Ball x134
Slot #13 Hyper Potion x44
Slot #14 Super Potion x32
Slot #15 TM44 x201
Slot #16 Calcium x243

After this item code, head to the room where you can pick up the gift Eevee. Do not pick up this Eevee yet, make sure to save before continuing.

Note: setting up ACE on an existing save

Before heading to the room where you can pick up the Gift Eevee, make sure to do the following:

  • Full up your party with 6 pokémon, to ensure that newly picked up Pokémon will be sent to the PC.
  • Change the active box to an empty box.
  • Only if you have already picked up the gift Eevee in the past, catch any pokémon, nickname it so that it matches the name shown below, then send it to the currently empty box.
Nickname

Note: unterminated name items in Eevee's room

Within this room, no safe spots exist that allow unterminated name items to be safely handled. Please make sure to not press a or select on unterminated items while in this room.

Step 5: Setting up an initial ACE environment using map script ACE

Now that we have an item code ready, we'll be using it to set up an ACE environment. The item code we just made looks at the nicknames of the pokémon in the currently stored box, then uses pairs of text characters to write a new program. After it finishes, it immediately jumps to execute the newly written program.

Having a party of 255 pokémon makes it impractical to safely enter battle. To circumvent this, we'll be picking up multiple Eevees, nicknaming them, then storing them in the current active box.

We'll be executing ACE by overwriting the contents of item slot #41. This item slot contains the map script pointer. By overwriting it with a pointer aimed for the 6th item slot, the item code we made will be executed on every individual frame the start menu isn't open.

We will be using this in three stages:

  • First we will alter a value in memory so that we can continuously keep picking up Eevees while we remain on the same map.
  • Next we will give ourselves a glitch item that, when used, will execute ACE starting from the sixth item slot. This allows us to execute ACE outside of the limits of Map Script ACE.
  • Finally we will set up a short program that uses the nickname screen to quickly and easily write programs of arbitrary size, effectively giving us a flexible ACE environment.

It is recommended to not save the game until the Nickname Writer program is installed.

A note on using ACE

The first generation of pokémon games, especially the Virtual console releases, are vulnerable to certain crashes wiping the save file. As a protective measure, make sure to open the trainer card to display Red's sprite on screen right before using ACE of any kind. Loading any sprite switches the current active sram bank, offering a measure of safety against game crashes.

Setting up Infinite Eevee mode

First, we'll use Map Script ACE to make sure that we can pick up as many Eevee as we want.

Nickname
  • Pick up an Eevee and nickname it so that its name matches the above screenshot on the left. It will be sent to the current active box. Previously existing saves that have already picked up Eevee in the past must skip this step.
  • Open the item bag. Swap the Calcium x243 with the contents of item slot #41, which should contain X Defend x86. This will activate Map Script ACE.
  • Close the start menu. If everything went all right, Eevee's poké ball will have reappeared.
  • Open the item bag. Swap the X Defend x86 that was previously in item slot #41 with the Calcium x243. This will deactivate Map Script ACE.
Slot #41

Setting up 4F to execute item codes

Next, we'll be entering a list of three nicknames that gives us 4F and the necessary bootstrap. This ensures that using 4F will activate the item code.

List of nicknames
  • Pick up Eevees and enter the nicknames in the above screenshot one by one. The nicknames from this list needs to be entered in this exact order from the top to the bottom.
  • Open the item bag. Swap the Calcium x243 with the contents of item slot #41, which should contain X Defend x86. This will activate Map Script ACE.
  • Close the start menu. If everything went all right, the CANCEL buttons in the first three slots have been removed and the first item was replaced with a glitch item named "4F"
  • Open the item bag. Swap the X Defend x86 that was previously in item slot #41 with the Calcium x243. This will deactivate Map Script ACE.
  • Finally, verify that 4F works by using it. If the game doesn't crash, 4F was set up correctly.
Slot #41

Setting up the Nickname Writer

  • Next, we'll be entering a list of thirteen nicknames. This will form a small program that, when activated using 4F, will allow us to easily write large amount of arbitrary code using the nickname screen.
List of nicknames
  • Pick up Eevees and enter the nicknames in the above screenshot one by one. The nicknames from this list needs to be entered in this exact order from the top to the bottom.
  • Once all nicknames have been entered, look at your trainer card, then use 4F. This should open a screen in which you're asked to enter a pokémon's nickname
  • For now, press START to end writing the nickname. This should display the main menu, a number should be written on screen.
  • Press SELECT to exit the Nickname Writer safely.

Using the nickname writer

From this point onward, whenever you use the ACE item, you should be able to open the nickname writer. Please make sure to keep note of the following:

  • Since the Nickname Writer works independently of the current active box, you can change the current active box however much you like.
  • When writing data, the Nickname Writer will overwrite enemy party data. While this does not have any effect outside of battle, it is recommended to not use the Nickname Writer in battle.

The program works as follows:

  • The program opens the nickname screen and asks you to input a nickname.
  • This nickname then gets converted to a sequence of five bytes.
  • All five bytes are written starting from the starting location
  • The program displays a glitched overworld view, along with a checksum (sum of all written byte values) towards the top right of the screen to confirm that you correctly entered the code. If the printed checksum doesn't match the expected checksum, you made a mistake entering a code. The glitched overworld view is temporary and will not affect your game.
  • Afterwards, it waits for the user to decide what to do.

During the input phase, the controls are as follows:

  • Press A for the program to ask for a new nickname and convert that to the next five bytes to be written.
  • Press B to go back one byte at a time. The checksum will automatically be overwritten by the value written at the current selected address, giving you a measure of how far back you're going. If a name is incorrect, press B five times before pressing A, entering the nickname again to overwrite the incorrect nickname.
  • Press START to immediately start executing the newly written program. Only do this when you've finished writing everything.
  • Press SELECT to safely quit the Nickname Writer, without executing the newly written code.
Write mode Input mode
Enter nickname, press select to switch between uppercase/lowercase Checksum ("4E", in this case) is displayed as a hex value on the top right quadrant

Step 6: Returning the game state to normal

At this point, there are certain side effects that have been introduced by the setup:

  • For all saves
    • By picking up Eevee, we have flagged its poké ball as "obtained"
    • The current active box is filled with nicknamed Eevees
    • The item pack currently has 255 items
    • The item code is currently still required to run the Nickname Writer
  • For new saves only
    • We currently have two badges set as obtained
    • Our pokédex currently has 152 pokémon species caught, preventing the story from continuing
    • Setting up SRAM glitch has given us a party of 255 pokémon
    • We are currently located in the Celadon Pokémon center, while we need to return to Pallet Town to pick up the starter pokémon

We will be removing all these side effect using the Nickname Writer. The nicknames we need to enter will be generated by the Nickname Converter webtool. Simply open the link, copy paste one of the two codes below into the converter, then press the "Run" button to display the list of nicknames. Please make sure that you use the Nickname Writer within a poké center, to ensure that the checksums are displayed properly.

When using the Nickname Writer, the generated nicknames need to be entered from top to bottom.

Please ensure to pick the code that suits your type of save.

Codes to be used with the Nickname Converter webtool
New Saves Older Saves 
21 AD D5 CB AE
AF EA 55 D3 21
7F DA 22 3D 22
AF 01 26 00 21
F6 D2 22 0D 20
FC 2E B0 22 22
23 23 22 22 EA
62 D1 EA 1C D3
01 01 59 CD 3F
3E 21 65 DA 36
69 23 36 D6 C9

21 AD D5 CB AE
AF 21 7F DA 22
3D 22 AF EA 1C
D3 21 65 DA 36
69 23 36 D6 01
01 59 C3 3F 3E

Once all nicknames have been entered and verified, you can press START during input mode to execute the code.

This will activate the following effects:

  • For all saves:
    • Reset the state of Eevee's poké ball, allowing it to be picked up again at a later point
    • Empty the current active box
    • Resets the bag, removing all items aside from 4F and removing the inventory underflow state
    • Rewire 4F so that it can activate the Nickname Writer independently of the item code
  • Only for new saves:
    • Reset all badges
    • Reset all Pokédex flags
    • Removes all party pokémon
    • Alters the exit of the poké center to lead out to Pallet Town

From this point onward, you can exit the penthouse and continue the story as normal.

Additional applications of the Nickname Writer

The Nickname Writer allows you to easily write and execute arbitrary payloads. You can either make and execute your own codes, or head to the Nickname Writer codes page. This page contains a collection of assembly for nickname codes that can be used for a variety of common purposes such as editing pokémon and items, editing player stats, resetting legendaries etc..

Nickname Writer Codes

Addendum: raw text transcripts of nickname codes

These are provided as an alternative in case images fail to load.

Infinite Eevee Mode Nickname

Nickname 
C l l U : V : ; W ;

4F Bootstrap Nicknames

List of nicknames 
g . y x ] , k Mn * Pk
* ( u z z , , . ] ,
w v u v U l k Mn Pk X

Nickname Writer

List of nicknames 
a b v v ) l l C d d
j ? ) V t v v v l Mn
q p y y ] z y p g F
v u j ? t K K b c c
R j j m v w w P P p
l l M v V V u l : ♀
P x w v v W M m m w
A B r q x Pk z g g h
i z , [ o w o x w x
( ) ) ) ) , , ] ] .
j ! U ? ? u w v u Mn
a Pk * t * A S j s t
r p P W [ : : ; : ;

Addendum: technical explanation of the setup

Nickname Converter Item Code

Explanation

The item code itself consists of two components. The first 10 items are used to write a program that takes text characters from the nicknames of characters currently within the active box, converts them, then writes the resulting values to unused memory starting from $D66A.

Pairs of text characters are converted to single values through a [(2a + b)%256] formula, where a is the value of the first character and b the value of the second. text terminators are skipped, the code will stop and execute the newly written code once it either reads a $00 value or if values are being read past $DEFF. 

11 69 D6	ld de, UNUSED_MEMORY	; Memory between $D669 and $D6EE goes unused
D5		push de
21 05 DE	ld hl, wBoxNicks
.loop
2A		ldi a, (hl)
03		inc bc			; Filler, no effect on flags
87		add a
0B		dec bc			; Filler, compensates previous inc bc, no effect on flags
30 04		jp nc, .notChar		; Aside from space (should not be used), "add a" will only give nc if value read is not a text char
86		add a, (hl)
12		ld (de), a
2C		inc l			; Affects z flag
13		inc de
.notChar
20 F4	jp nz, .loop			; Loop unless l rolled over to $00 or value read was $00
C9		ret			; Due to previous push de, this ret will cause execution to resume from $D66A onward, immediately running the newly written code

The last item, the Calcium, simply form a pointer to $F327. Due to echo RAM this address is equivalent to $D327, which correspond to item #6's item ID, the start of the item code. By replacing the map script pointer with this item, we can redirect the map script routine to execute the item code instead. This routine is executed on every frame, as long as the start menu isn't open.

Raw Assembly

11 69	Max Potion x105
D6 D5	TM14 x213
21 05	Thunderstone x05
DE 2A	TM22 x42
03 87	Great Ball x135
0B 30	Antidote x48
04 86	Poké Ball x134
12 2C	Hyper Potion x44
13 20	Super Potion x32
F4 C9	TM44 x201

27 F3	Calcium x243

Infinite Eevee Nickname

Explanation

The Infinite Eevee mode nickname writes $00 to the lower byte of wMissableObjectList, causing a misalignment in how the game applies NPC disappearance, causing Eevee's pokéball to stay permanently visible until the game is reset or the player leaves the Celadon Mansion penthouse. 

AF		xor a				; a = $00
EA CD D5	ld (wMissableObjectList), a	; Misaligns which objects are made invisible
C9		ret

Raw Assembly

AF EA CD D5 C9

4F Boostrap Nicknames

This set of nicknames, when converted, will modify item #1's ID to be 4F and writes a bootstrap so that using it will lead to execution of the item code from $D327 onward. It requires the presence of the Infinite Eevee Mode Nickname (see previous section) to properly return. 

21 1D D3	ld hl, wBagItems	; item #1's ID
36 59		ld (hl), $59		; 4F's item ID
7C		ld a, h			; a = $D3 
21 66 DA	ld hl, 4F_Execution_Pointer +2
32		ldd (hl), a
3E 27		ld a, $27
22		ldi (hl), a
36 C3		ld (hl), $C3
; The contents of the first nickname (see previous section) are written right after this, ensuring safe return.

Raw Assembly

21 1D D3 36 59
7C 21 66 DA 32
3E 27 32 36 C3

Using 4F

Explanation

Using 4F, an invalid item, will cause the game to index the item effects table out of bounds, leading to an invalid execution pointer. For 4F, this causes the game to execute code from $FA64 onward. Due to echo RAM, this address is equivalent to $DA64. Thanks to the bootstrap that was applied earlier, this will then cause the game to jump to $D327, corresponding to the start of the item code. 

C3 27 D3	jp ITEM_6_ID

Raw Assembly

C3 27 D3

Nickname Writer

Explanation

The Nickname Writer is a small program that, using nicknames as input, is able to write arbitrary amounts of custom code relatively quickly. It first request a nickname as input, then converts that data to custom code, then displays a checksum of the written data and finally asks the player to provide additional input.

The value of the checksum is calculated by [($80 + the sum of all written values)%256]. Custom code is buffered and executed within enemy party data. Due to how it calls DisplayNameRaterScreen, it will also nickname a party pokémon corresponding to the item slot that 4F currently occupies. 

11 B4 D8	ld de, $D8B4			; location written to
D5		push de
.newMail
D5		push de
21 95 62	ld hl, AskName + 39h		; Prepares data and calls DisplayNamingScreen
CD 17 39	call $3917			; sets b to 01, then jumps to Bankswitch, calling b:hl
0E 80		ld c, $80			; Ensure checksum consistency
21 4A CF	ld hl, wStringBuffer		; Address where new name gets written to
D1		pop de				; Continue writing from last saved de
.newChar
2A		ld a, (hli)
87		add a
30 09		jp nc, .terminator		; If blank space as first character of pair, only terminator $50 will result in a nc result
86		add a, (hl)
12		ld (de), a
13		inc de
23		inc hl
81		add a, c			; Current checksum total is buffered in c
12		ld (de), a
4F		ld c, a
18 F3		jp .newChar
.terminator
D5		push de
21 00 C4	ld hl, $C400			; Corresponds to screen tile
0E 01		ld c, $01			; How many bytes printed as numbers?
CD BF 13	call PrintBCDNumber.loop
.numLoop
2D		dec l
CB FE		set 7, (hl)
20 FB		jp nz, .numLoop			; Repeat until hl == $C400
75		ld (hl), l			; Nulls out $C400
.inputLoop
CD 1E 38	call JoypadLowSensitivity	; Halt execution until frame has passed, get joypad status and store result in hJoy5
F0 B5		ld a, (hJoy5)
E6 0F		and $0F				; Set z flag if A, B, START, SELECT not pressed
28 F7		jp z, .inputLoop
1F		rra				; Is A pressed? If yes, set c flag
D1		pop de
38 CB		jr c, .newMail
1B		dec de
1F		rra				; Is B pressed? If yes, set c flag
38 E1		jr c, .terminator
1F		rra				; Is SELECT pressed? If yes, set c flag
E1		pop hl				; pop starting address to hl
D8		ret c				; If SELECT pressed, simply return to normal operations
E9		jp hl				; If START pressed, jump to hl to execute newly written code

Raw Assembly

11 B4 D8 D5 D5
21 95 62 CD 17
39 0E 80 21 4A
CF D1 2A 87 30
09 86 12 13 23
81 12 4F 18 F3
D5 21 00 C4 0E
01 CD BF 13 2D
CB FE 20 FB CD
1E 38 F0 B5 E6
0F 28 F7 1F D1
38 CB 1B 1F 38
E1 1F E1 D8 E9

Cleanup Code (new save)

Explanation

This code cleans up every negative side effect brought on by the setup and allows the player to continue the story as intended, with the exception of 4F being added to the item bag, enabling use of the Nickname Writer.

The negative effects targeted are:

  • By picking up Eevee, we have flagged its poké ball as "obtained"
  • The current active box is filled with nicknamed Eevees
  • The item pack currently has 255 items
  • The item code is currently still required to run the Nickname Writer
  • We currently have two badges set as obtained
  • Our pokédex currently has 152 pokémon species caught, preventing the story from continuing
  • Setting up SRAM glitch has given us a party of 255 pokémon
  • We are currently located in the Celadon Pokémon center, while we need to return to Pallet Town to pick up the starter pokémon
21 AD D5	ld hl, $D5AD		; Part of wMissableObjectFlags
CB AE		res 5, (hl)		; Reenable Eevee's poké ball
AF		xor a			; a = $00
EA 55 D3	ld (wObtainedBadges), a	; Reset badges
21 7F DA	ld hl, wBoxCount
22		ldi (hl), a		; Set amount of pokémon in box to 0
3D		dec a			; a = $FF
22		ldi (hl), a		; Add proper terminator to wBoxSpecies
AF		xor a			; a = $00
01 26 00	ld bc, 0026
21 F6 D2	ld hl, wPokedexOwned
.loop
22		ldi (hl), a
0D		dec c
20 FC		jp nz, .loop		; Fully clear all Pokédex flags
2E B0		ld l, $B0		; hl = $D3B0, within wWarpEntries
22		ldi (hl), a
22		ldi (hl), a
23		inc hl
23		inc hl
22		ldi (hl), a
22		ldi (hl), a		; Changes first two warp tiles to lead to Pallet Town instead
EA 62 D1	ld (wPartyCount), a	; Set amount of pokémon in party to 0
EA 1C D3	ld (wNumBagItems), a	; Set amount of items to 0
01 01 59	ld bc, $5901
CD 3F 3E	call GiveItem		; Gives c amount of b item, giving 1 copy of 4F.
21 65 DA	ld hl, $DA65		; Part of 4F bootstrap
36 69		ld (hl), $69
23		inc hl
36 D6		ld (hl), $D6		; 4F now redirects directly to Nickname Writer
C9		ret

Raw Assembly

21 AD D5 CB AE
AF EA 55 D3 21
7F DA 22 3D 22
AF 01 26 00 21
F6 D2 22 0D 20
FC 2E B0 22 22
23 23 22 22 EA
62 D1 EA 1C D3
01 01 59 CD 3F
3E 21 65 DA 36
69 23 36 D6 C9

Cleanup Code (existing save)

Explanation

This code cleans up every negative side effect brought on by the setup and allows the player to continue the story as intended, with the exception of 4F being added to the item bag, enabling use of the Nickname Writer.

The negative effects targeted are:

  • By picking up Eevee, we have flagged its poké ball as "obtained"
  • The current active box is filled with nicknamed Eevees
  • The item pack currently has 255 items
  • The item code is currently still required to run the Nickname Writer

Since existing saves do not have to set up SRAM glitch, there are a lot less side effects that need to be addressed by the cleanup code. 

21 AD D5	ld hl, $D5AD		; Part of wMissableObjectFlags
CB AE		res 5, (hl)		; Reenable Eevee's poké ball
AF		xor a	; a = $00
21 7F DA	ld hl, wBoxCount
22		ldi (hl), a		; Set amount of pokémon in box to 0
3D		dec a	; a = $FF
22		ldi (hl), a		; Add proper terminator to wBoxSpecies
AF		xor a	; a = $00
EA 1C D3	ld (wNumBagItems), a	; Set amount of items to 0
21 65 DA	ld hl, $DA66		; Part of 4F bootstrap
36 69		ld (hl), $69
23		inc hl
36 D6		ld (hl), $D6		; 4F now redirects directly to Nickname Writer
01 01 59	ld bc, $5901
C3 3F 3E	jp GiveItem		; Gives c amount of b item, giving 1 copy of 4F.

Raw Assembly

21 AD D5 CB AE
AF 21 7F DA 22
3D 22 AF EA 1C
D3 21 65 DA 36
69 23 36 D6 01
01 59 C3 3F 3E
Retrieved from "https://glitchcity.wiki/wiki/Guides:SRAM_Glitch_ACE_Setups_(EN_Yellow)?oldid=44105"