This tutorial aims to teach you how to insert .asm patches. These aren't the same as .bps or .ips patches like the ones you use to share and play whole hacks, but rather additions and changes you can make to your game using the ASM programming language, the language the Super Nintendo Entertainment System (SNES) understands.
Of course, that doesn't mean you have to program anything yourself or learn anything complicated just to apply a patch, it's all in the file you downloaded already! Your job is simply to use a program called Asar to apply the patch to your SNES ROM. It doesn't matter if the ROM is "clean" or not, .asm patches will generally work on any ROM.
Download: Asar
Please prepare your own .asm patch before move on.
1 Setting up .asm patches
Extract asar.exe and the patch you downloaded, xfusion.asm in this example, to the same folder (say, a "patches" folder in your main hack folder) and place your ROM into the same folder.
You can ignore everything other than asar.exe in Asar's .zip file.
2 The patching process
There are two quick ways to patch individual patches: by double-clicking Asar and through the Command Prompt (cmd).
Generally, using Asar itself is easier and faster and I will explain a method to speed up patching multiple patches at once further below, but knowing how to use Asar in the Command Prompt is good either way.
2.1 Patching through Asar
For this method, simply double-click on Asar itself and a black window will pop up, introducing itself as "Asar, by Alcaro" and asking you to enter the patch's name. Write in your patch's filename, in this example that would be xfusion.asm, and hit enter.
Next it will ask you for the name of your ROM. Again, just write in the filename of your hack, like Super Metroid.smc, My Hack.sfc or whatever else your own ROM might be titled. Hit enter and squadala, we done.
Make sure that Asar does not throw any errors but instead reports that "Assembling has completed without problems", close the window by pressing any key and boot your ROM up in an emulator to see if the patch did what it promised.
2.2 Patching through the Command Prompt
This method takes a bit longer, but is good to know should you be more acquainted with the Command Prompt already or if you need to patch multiple patches, since the window will not close by itself and previous commands can be copied back by tapping the Up-Arrow key.
It's a lot more time efficient when you're testing changes in a patch over and over as well, since you can simply tap the Up-Arrow and hit enter to re-patch it each time.
To open the Command Prompt, hold shift while right-clicking on the folder Asar is in. There will be a normally hidden entry in the context menu called "Open command window here". Click it and the Command Prompt will pop up.
To apply a patch from here, type the following and hit enter:
asar.exe "xfusion.asm" "Super Metroid.sfc"If the patch was applied correctly, there will be no confirmation, but also no errors. It should look like the image to the right.
Now, try hitting the Up-Arrow key in this window. The previous line will be copied again and you can hit enter once more to apply the patch a second time, or a third or fourth time.
You don't have to re-open the Command Prompt window after changing anything in your ROM either, it will only access the ROM the second you hit enter.
3 Run Asar on macOS
Use CrossOver to run this software on macOS: simply click "Run Command" on the bottle main screen and choose asar.exe to open Command Line (for some reason, you can't do this by double click the .exe file).
Be sure to put the files in the same directory. Then everything is the same!