The first 128 bytes contain the ID MC in ASCII.
If you have a save file from another emulator like RetroArch or a DexDrive, you can manually create the epsxe000.mcr file by renaming them: From RetroArch (.srm) : Copy your .srm file, paste it into the ePSXe folder, and rename it to epsxe000.mcr From DexDrive (.gme) : Change the file extension from : Ensure "Hide extensions for known file types" is epsxe000.mcr