Custom Chipset

Amiga Hardware

The Classic Amiga's multimedia capabilities were mainly down to the inclusion of special Custom Chips. These handled graphics and sound seperately from the main CPU, much like a modern GPU does. Each chip handles a specific set of tasks, directly accessing the Chip RAM. Custom chips were given names such as "Agnus", "Paula" and "Denise" (see the articles on specific chipsets for a list of chips used).

The first chipset was the OCS or Original Chip Set, used in the A1000, A500 and A2000. This was later superceeded by the slightly improved ECS (Enhanced Chip Set) as found in the A500+, A600 and A3000. The final chipset to be produced was AGA (Advanced Graphics Architecture). This was a far greater development from ECS than that chipset was from OCS (for instance a Palette of 256 was used). Despite these improvements, the Amiga's capabilities were arguably not as stunning compared to competing platforms as the had been in 1987; AGA had been ready when the A600 was released however Commodore had decided to delay it.

A further chipset, AAA, was under development, but had to be cancelled when Commodore ran into fianancial difficulties. Prototypes existed and speculation has continued on whether the design could ever be implemented now, however the designs are no longer avaliable, and would give far inferior performance to a cheap graphics and sound card. In addition, Commodore was in early development of a post-AAA chipset, called Hombre based around the PA-RISC processor core. Details of this design, however, are sketchy at best. The Access? was the last machine to be produced in any quantity that used the custom chipset and the BoXeR, had it ever been released, would have used a clone of the entire AGA chipset on a single chip.

Third-party graphics and sound cards have been avaliable for the Amiga for a long time, and the new generation of PowerPC-based Amigas do not use a custom chipset at all, instead relying on retargetable graphics and a soundcard supported by AHI.