Save The Hero Builders have just begin selling the latest version of their cart reader, called the V3-ALTER. The base unit supports SNES, Genesis, GB/GBC/GBA and N64 cartridges and starts at $150 plus shipping. There’s also new cartridge adapters available for many different consoles, including the Game Gear and Virtual Boy! More info below the links:
Cart Reader: https://savethehero.builders/products/open-source-cartridge-reader-v3-alter-build-service
Cartridge Adapters: https://savethehero.builders/collections/cartridge-adapters
Sanni Cart Reader Github: https://github.com/sanni/cartreader
This cart reader is based off the Sanni Cart Reader, however it’s a fork of the project. Both are excellent and you’re welcome to check out the open source github page to see if you’d like to build your own, or even use the new Sanni design instead of this one. That said, if you’re just looking to order one without building anything yourself, these seem like a great choice.
Also, Tito from Macho Nacho Productions did a video on a slightly older version, however it’s still totally relevant and should be more than enough to get your started: