You can't, a CD-ROM has already been authored and you can't change the contents.
Click on File, then Save, and make a file for your save. Every time you turn on the ROM, you'll click on File, then Load, and open your save file.
You can't save anything on a CD-ROM. This is because ROM means Read Only Memory. Most songs are like this so you cannot re write on them.You can save most types of popular picture (JPEG/GIF/PNG etc) video (AVI/MP4/MP1 etc) and music (MP3/ AAC/ WAV etc) files onto CD-Rs and CD-RWs.
CDFS CD Rom File System is relatively simple format defined as the read only formatting standards for cdrom media.
Yes, there's no real reason to believe a CD rom would be unable to hold a file in certain formats, all formats are digital in nature on a computer, stored in a binary format, and copied as such onto a CD ROM when it is mastered.
To recover your save file in DeSmuME CLI, locate the save file usually named with the same title as your ROM but with a .dsv extension. Ensure that the save file is in the same directory as your ROM or specify the path in the command line. You can load the ROM along with the save file using the command: desmume-cli yourrom.nds yoursavefile.dsv. If your save file is missing or corrupt, check for backups or previous versions if available.
VFAT File system......... Virtual File Allocation Table.
You have a flash cart?You have to rename the save file to the name of your nds. file
piemel
To open a saved file in DeSmuME, first launch the emulator and load your game ROM by selecting "File" > "Open ROM" and navigating to your ROM file. Once the game is running, click on "File" again, then select "Load State" to choose your saved state file, which typically has a .dsv extension. If you’re using save files in the form of battery saves, ensure you have the correct save file in the same directory as the ROM with the appropriate naming convention. After loading the save, you should be able to resume your gameplay from where you left off.
optical disls
Kodak Picture CD
Simply get rid of the ROM and Save File.