Link Cable for Pokémon Red/Blue Between Game Boy Color and Advance/SP? Impossible.

You cannot directly link a Game Boy Color (GBC) to a Game Boy Advance (GBA/SP).

• Different Connectors/Protocols: GBC and GBA link ports are physically and electrically incompatible.
• Game Incompatibility: Pokémon Red/Blue (Gen 1) were not programmed to communicate with GBA hardware.

To Trade/Battle in Gen 1

1. Two Game Boy Color (or original Game Boy) systems.
2. One Game Boy Color Link Cable (universal for GB/GBC).

Cable Compatibility Summary

• GBC ↔ GBC: Standard GBC Link Cable.
• GBA ↔ GBA: GBA Link Cable.
• GBC ↔ GBA: Impossible with standard cables.