Programming Language of Game Boy Pokémon Games: Assembly (Z80/Sharp LR35902)

The Game Boy Pokémon games (Red, Blue, Yellow, Gold, Silver, Crystal) were written in assembly language (Z80/Sharp LR35902).

Assembly was standard for Game Boy development due to:

• Severe hardware constraints (4.19 MHz CPU, 8 KB VRAM, 64 KB address space).
• Need for cycle-precise optimization.
• Direct hardware manipulation (LCD controller, sound registers, memory banking).

Higher-level languages (C) existed but produced bloated code unsuitable for the platform. Modern disassembly projects (e.g., pokered) have reverse-engineered the source into readable assembly.