Devices to rip saves to PC (and the reverse) were not very common back when, however some companies did make devices to rip them from the games themselves and store them internally to either flash to your cartridge again or to a friend's copy.
Mostly then used to increase save slots if the game did not provide them or external memory support (one game for several kids, or be able to lend a game to someone, and I guess the camera thing noted above), do save restoration type cheat approaches (assuming the device itself did not outright support cheats, some later consoles even seeing such devices edit saves), for some reviewers if old scenes could not be replayed but pictures or something needed after the playthrough.
Today if not just emulating outright you would generally be advised to seek out a PC ripping tool (various vendors that sell flash carts, repair kits, screen replacements, adapters and such will tend to have them for given consoles), or maybe one of the cartridge playing devices (everything from the retron5 to analogue pocket) as they may have some manner of doing this as well (if you are running your own code, have an SD slot and can speak to a cartridge to get the save for normal play it is easy enough to fire to SD or possibly even network). If it was the GBA or DS you might be able to find a flash cart to do what you want, GBC linkers are far more rare though (and adapting a GBA one just as fraught with difficulty, not to mention if you can solder
https://hackaday.com/2011/05/09/avr-gameboy-dumper/ and possibly also multiboot cables if your machine still has a parallel port).
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BigOnYa:
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K3Nv2:
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ZeroT21:
