Atari Sierra prototypes Documentation

The Atari Sierra prototypes documentation below is the Rainbow graphics overview hosted for the Atari Sierra project.

Rainbow overview, 30 November 1983

Atari, Inc.'s overview of Rainbow, the graphics chip set designed for the Sierra computer, is dated 30 November 1983 and marked "Atari Company Confidential. Do Not Duplicate." on every page. The hosted copy is a 40-page text PDF from the Internet Archive's "Atari Rainbow chipset documentation" collection, which Bob Alkire, one of Rainbow's designers, provided in March 2020.

Contents

• 1. Introduction: preface, key features, overview of function, objects, screen organisation, colour palette, memory and CPU communication
• 2. Functional description: objects, pictures and windows, picture data formats, object priority, object parameters, parameter block layout, pixel data formats, colour map, global control modes and values, register addresses
• 3. Hardware implementation (from p. 21): system connection, pinouts, Gold and Silver block diagrams, screen format, video and status timing, refresh cycle, reset sequences, colour map writes, interrupt timing, read/write cycle
• 4. Performance of Rainbow (from p. 35): speed and available cycles

What this document does not contain

• Anything about the rest of the Sierra computer: the processor, memory system, sound chip, case or operating system.
• The detailed chip specifications, which are separate documents in the same Internet Archive collection.

Pages that cite this document

• Atari Sierra prototypes: Rainbow's features, object processors and memory interface

Download: Atari Rainbow Overview (30 November 1983).pdf