• Introduction
• Patching Formats
• Rom Preparation
  • CRC32
  • Filesize
  • Headers
• Patching Methods
  • Soft Patching
  • Hard Patching
• Troubleshooting
  • Symptoms
  • Black screen at startup
  • Game runs, but it looks / plays glitched, crashes
• Tool repository by function
  • Patchers
  • Suites
  • Snestool
  • Segatool
  • Nach's Snes Rom Tools - NSRT
  • Good Tools
• Closing thoughts

This simple guide attempts to cover any doubts novice emulator users may have. While this file has no intention of teaching users how to use emulators, it will try to instruct players on how to prepare their rom files for use with our patch releases.

In order to patch successfully one must prepare their rom files accordingly. Always refer to the readme file of the patch you intend to use before doing anything else, you'll save yourself a lot of time and frustration, trust me on this.

Pay attention to the parameters the readme file specifies; I will cover some of them.

A 32-bit cycle redundancy check. In layman's terms it basically tells you if the rom you have matches the the rom the patch requires.

It is also a good idea to have a good rom tool for the system in question, it checks whether the copy you have is a verified dump and therefore useable.

Its not uncommon that rom sites will add symbols to the files they make avaliable. To spare readers from unnecessary information, suffices to say one should always look for a [!] on the name of the file, it signifies a good dump by standard.

Readme files will usually contain the filesize of the proper rom for the patch used, and its usually expressed in bytes. To check that, make sure your rom is unzipped and right click it, then click on properties and check the size in bytes. If it doesn't match you either have a bad dump or you need to add or remove headers from the rom.

A header us a part if a rom's memory that contains some basic data about the file, like version and extension; while it tends to be unecessary for emulation purposes, some patches require that a header is present to function.

Soft Patching refers to the method of applying a patch to a rom to modify it through the emulator of your choice, for the duration of your usage session. It is the simplest method and should always be the first attempted by the user if at all possible.

To use soft patching, follow the steps below, replacing the generic notations I'll use for tutorial purposes with the names of your own files:

-> Enable soft patching in your emulator of choice The support to soft patching and how to enable it varies from emulator to emulator, please refer to the documentation of your emulator of choice for further instructions.

-> Place your rom file and patch file in the same directory e.g: I created the directory C:\Games then placed myrom.smc and myrom.ips in there. If done correctly, the rom will be patched when you run it.

Hard Patching refers to the method of applying a patch to a rom to modify it permanently. For this reason, its important to keep clean (unpatched) copies of your rom handy when hard patching is necessary. One may ask why use hard patching at all; the main reason being some patches behave oddly unless hard patching is used and as much as that is not a common happening, it is a possibility.

To use hard patching, besides a clean copy of the rom and the patch file one requires a patcher program and despite the abundance of such programs on the internet, they are fairly simple and intuitive to use and using any given one is really a matter of taste or the OS in question.

A good repository of patchers:

http://www.zophar.net/utilities/patchutil.html

Alternatively:

http://www.romhacking.net/?category=2&Platform=&game=&author=&os=&level=&perpage=20&page=utilities&utilsearch=Go&title=&desc=

When something goes wrong, here's where to look.

When a patching process goes wrong, the emulator will usually tell you so, and while it won't yell at you for it or throw a tantrum, there are ways to tell what could be wrong.

This usually means something went wrong in the rom preparation phase, For example trying to patch a headered rom when a patch expressely requires otherwise or vice versa will certainly cause these startup hangs.

Get a clean copy of your rom and review the points above, try to understand what you could have done wrong. If you soft patched and got this result, try hard patching instead. Note that in the Genesis' case errors of this nature are usually shown as a red screen at startup.

This usually means an imperfect or somehow deffective or altered version of the rom was used for the patching, and despite it apparently working, the end result is not stable or playable as intended.

Double check the CRC32 value and make sure you're using a good dump of the rom that has a [!] in its name

Here you'll find the necessary tools to perform the operations explained in this document.

These will hard patch a a rom.

http://www.zophar.net/utilities/patchutil.html

Alternatively:

http://www.romhacking.net/?category=2&Platform=&game=&author=&os=&level=&perpage=20&page=utilities&utilsearch=Go&title=&desc=

Programs that combine one or more functionalities described in this guide.

Old fashioned but functional rom handling suite for the SNES, can remove headers if necessary.

Same functionality as above but aimed at Genesis roms.

A more current tools suite for SNES roms, can perform a variety of operations including header handling.

These will verify your rom integrity for you, in other words if it is a usable dump.

http://www.allgoodthings.us/mambo/index.php?option=com_simpleboard&Itemid=42&func=showcat&catid=4

Make sure you read this document carefully, its a lot of information so don't expect to get it all at once. It will become second nature if you let it but it will take a lot of trial and error, so just do the most fail proof thing ever - practice. If this document was unable to clear up all your question and provided you tried hard enough by yourself to solve your problems and couldn't, address your questions to Our Forums.

-Red Soul