ECS (Enhanced Chip Set) is the second generation of Amiga custom chips introduced in 1990 with models like the Amiga 500+. It features Super Agnus supporting up to 1MB or 2MB of Chip RAM and Super Denise enabling new display modes including Productivity Mode (640x480 non-interlaced). ECS maintains backward compatibility with the original OCS while adding capabilities for VGA monitor support and improved graphics flexibility.