23 users online: Angel Miranda, autisticsceptile1993, Batata Douce, BeancityMakes, bersi, Coille, com_poser, Cote de Boeuf, h.carrell, HammerBrother, Idrinkgrapesoda, lordkronos100, Minish Yoshi, NewPointless, Saela, simon.caio, SomeGuy07, Starius65, The_Uber_Camper, thefoxx87, Tulip Time Scholarship Games, UTF, yogui - Guests: 238 - Bots: 188
Users: 64,443 (2,492 active)
Latest user: LetsAGo123

Frequently Asked Questions

Don't worry, we all need to start somewhere—if you're a beginner and still need to find your way around, chances are the F.A.Q. will answer a lot of the questions you may have. Before asking in the forums, it's wise to check this page first!

If you have suggestions for the F.A.Q., feel free to contact a staff member.

Getting Started

How can I edit Yoshi's Island?
The current editor for Yoshi's Island is Golden Egg v0.005 by Romi. (Please note that Golden Egg is a beta, and may contain undocumented bugs.) The current version of Golden Egg requires .NET framework 4.0.

Before Golden Egg's release, Eggvine, a glitchy editor by Squash Monster that crashes a lot and doesn't display graphics, was the best editor available. Eggvine v0.81+ is a slightly modified version by Yoshis Fan that contains better object rendering and object/sprite descriptions, making it much easier to use than the official versions.
Which Yoshi's Island ROM version do I need?
Super Mario World 2 - Yoshi's Island (V1.0) (U). The correct version of the ROM should have a CRC-32 checksum of D138F224. Snes9x displays this checksum when you load the ROM; other emulators should have a method to display ROM info where you can see the checksum.
My ROM's CRC-32 checksum is CF98DDAA instead. What do I do?
Check the file size. If it is 2,097,664 bytes, you can apply this patch using Floating IPS in order to correct your ROM.
In case the file size is 2,097,152 bytes, use HeAdder in order to add the SMC header to the ROM, then apply the patch using Floating IPS.
Do I need a headered or a headerless ROM for hacking Yoshi's Island?
Golden Egg supports both headered and headerless ROMs, but if you're using other tools, make sure you're using a headered ROM. If your Yoshi's Island ROM is exactly 2,097,152 (0x200000) bytes, it's headerless; if 2,097,664 (0x200200), it's headered. (Other values mean your ROM probably isn't a clean ROM; find a different one).

If you're creating an IPS patch, make sure your original and modified ROMs are either both headerless or both headered, and state which type when you release the patch (since it must be patched to the same type of ROM). YI hacks that use the IPS format (like most of the ones hosted on other sites) will require a headered ROM.

With BPS patches, it does not matter if the ROM being patched to is headered or unheadered.
I found a bug in Golden Egg. What do I do?
Report it in the General Golden Egg Discussion thread.
When will (insert planned feature here) be added to Golden Egg?
Due to Romi's inactivity, it is highly unlikely that there will be any future updates to Golden Egg. Your best bet is to wait for a new editor to be released instead.
After editing my ROM with [insert tool here], I opened it in the emulator and it said checksum fail or bad checksum. What's wrong?
Nothing is wrong. Making almost any change to a ROM will cause the checksum to fail. Some tools (such as Golden Egg, and the SMW editor Lunar Magic) auto-correct the checksum when you save the hack, but if you use another tool or a hex-editor, you'll probably have a bad checksum after that. There are tools available to fix the checksum, but there's no reason to do that unless you're about to release the hack.
Golden Egg says I'm out of free space. Help!
Due to the way that Golden Egg saves levels, it may be unable to find free space before all free space is actually used up. In this case, you should try using furious' Yoshi's Island Level Tool to extract all levels and insert them back into a clean ROM.
Can I hack Super Mario Advance 3 (the GBA version of Yoshi's Island)?
Not directly with Golden Egg or Eggvine, but if you've made a hack of the SNES version, you can try using adolif2's SNES-to-GBA level converter to convert it to GBA format. Note that the SMA3 level format is not entirely known, so your level may contain camera-scrolling problems or other glitches.

This thread contains general SMA3-hacking offsets. Note: A good amount of experience with hacking the SNES version is highly recommended to understand the SMA3 data.

There are multiple editors for SMA3 currently in development.

This F.A.Q. assumes you're hacking the SNES version.