RA90 Disk Drive Illustrated Parts Breakdown

This document is an Illustrated Parts Breakdown (IPB) manual for the RA90 Disk Drive, published by Digital Equipment Corporation in 1988.

Its primary purpose is to identify and catalog all components and assemblies of the RA90 Disk Drive, assisting users in understanding its construction, finding specific parts, and facilitating maintenance or ordering.

The manual is organized into several key sections:

• "How to Use the IPB": Provides detailed instructions on navigating the document, explaining the structure of the indented parts lists, column callouts (e.g., DEC Part No., ECO Cut-In, Used On Code), and the overall organization.
• Illustrated Figures and Indented Parts Lists: Presents exploded-view diagrams of the RA90 Disk Drive's major assemblies and sub-assemblies (e.g., HDA/Carrier, Blower/Bezel, Chassis, Electronic Control Module, Head Disk Assembly, Brake Assembly). Each figure is accompanied by a corresponding list detailing each part, its description, and part number, with asterisks indicating subordination within assemblies.
• Revision History: Documents changes to the parts information, including ECO levels and dates.
• Part Number/Description Sort Sections: Provides comprehensive alphabetical listings of all parts by both their Digital Equipment Corporation (DEC) part number and their description, aiding in quick lookup.

In essence, it's a comprehensive technical reference for the physical components of the RA90 Disk Drive.