RAMDisk lets you create drives in FAT16 and FAT32 or emulate an unformatted one so you can configure it as NTSC. The size limit for the free version of this program is 4 gigabytes, although you obviously can't create a disc that takes up more RAM than you have available on your computer. It's also not a good idea to use up all your RAM since it will slow down many of your computer's processes.
From the program's setup screen you can select the size and format of the drive you want to emulate. You'll also be able to save an image when the program stops and recover it on startup.
This tool will allow you to optimize programs that generate large caches, like databases or even your web browser. You can even use the drive as a temporary file storage for Windows.
The maximum disc size for the free version is 4 GB.