In the emulation world, this lock-on process is not automatic. Early emulators struggled to replicate the cartridge-slot passthrough. To solve this, ROM hackers and tool creators developed that combine both games into a single .bin file.
If you own both original cartridges, here’s how to build the file yourself: sonic knuckles wsonic3bin file
The sonic3.bin (or wsonic3.bin ) file is the core ROM data for Sonic the Hedgehog 3 In the emulation world, this lock-on process is