Gopher64 stores saves in big-endian format (the same as the N64). This means that you can use saves from a flashcart directly with Gopher64.

Simple64 (and other mupen64plus-based emulators) and Project64 store SRAM (.sra) and Flash (.fla) saves in reverse (little-endian) format. These need to be converted before they can be used in Gopher64. Mempak and eeprom saves shouldn't need to be converted.

Here is an example of how you can convert one of these files on Linux:

objcopy -I binary -O binary --reverse-bytes=4 input_file.sra output_file.sra

Once converted, you can click on theOpen Saves Folder button in the emulator to open the folder with save files on your computer.

Files will be named like this:

MarioGolf64-871134C893D5D671EF90C88DFBE98FB20FA20853B3370936A1D09AEE6DE1BEAE.sra

The871134... part is the sha256sum of the ROM in .z64 (big-endian) format. You can replace the existing save with your converted save from another emulator.