Commodore Amiga Chipset
The custom chip symphony
The Amiga's custom chipset—Agnus, Denise, and Paula—worked in concert to deliver graphics and sound capabilities that outclassed competitors for years.
Overview
The Amiga’s power came from three custom chips working together: Agnus handled memory and the blitter, Denise generated video output, and Paula managed audio and disk I/O. This division of labour freed the 68000 CPU for game logic while dedicated hardware handled graphics and sound. The Original Chip Set (OCS) evolved through Enhanced (ECS) and Advanced Graphics Architecture (AGA).
Fast facts
- Designer: Jay Miner and team.
- Original Chip Set (OCS): Amiga 1000, 500, 2000.
- Enhanced Chip Set (ECS): Amiga 3000, 500+.
- AGA: Amiga 1200, 4000 (256 colours from 16 million).
The triumvirate
Each chip’s role:
- Agnus: DMA controller, blitter, Copper coprocessor.
- Denise: video output, sprite generation, colour registers.
- Paula: 4-channel audio, disk control, interrupts.
Chipset evolution
Generations of improvement:
- OCS (1985): 32 colours (4096 palette), HAM mode.
- ECS (1990): productivity modes, bug fixes.
- AGA (1992): 256 colours (16 million palette), 8 sprites.