DEC-DiskStorageSolutions

This document describes Digital's RD family of 5.25-inch Winchester disk drives, designed as versatile storage solutions for desktop and deskside computing environments.

Key aspects of the RD family include:

• Models and Capacities: The line comprises full-height drives (RD54 - 159 MB, RD53 - 71 MB) typically for pedestal/cabinet systems, and half-height drives (RD32 - 42 MB, RD31 - 20 MB) for desktop use.
• Connectivity: All RD family drives connect to Q-bus systems via a single RQDX3 Controller.
• RQDX3 Controller Features: This controller offloads low-level disk control from the host processor, supporting up to four peripherals (including floppy drives). It enhances system throughput and data integrity through features like overlapped seeking, buffered seeks, an elevator seek algorithm, 32-bit Error Correction Code (ECC), and automatic bad block replacement.
• Digital Storage Architecture (DSA): A core design principle is conformance to DSA, which ensures compatibility with other Digital storage products, promotes future expandability, and protects customer investment.
• Reliability and Performance: The drives are thoroughly tested to stringent Digital standards, utilizing proven technologies like sealed head/disk assemblies to minimize contamination, enhance reliability, and eliminate the need for preventive maintenance. They offer competitive average access times (e.g., 38.3 ms for RD53/54, 48.3 ms for RD32) and a peak transfer rate of 5.0 Mb/s.
• Benefits: The RD family emphasizes low cost of ownership, proven investment protection, high system availability, and flexible growth and expansion options.

The document also provides detailed specifications tables covering performance metrics (seek times, transfer rates, formatted capacity), data organization, operational characteristics, power requirements, physical dimensions, and environmental parameters for all RD models.