Flexible Disk Data Storage Systems

This document is a service manual for the DSD 440 and DSD 480 Flexible Disk Data Storage Systems. It covers:

• General Information: Provides the purpose, scope, service philosophy, and customer service contact information.
• Interface Modules: Describes the specifications and pin connections for the Interface Bus (I-Bus).
• Controller Module: Offers a detailed theory of operation for the controller, covering the 8085 microprocessor, bus structures, clock circuitry, master controller nucleus, and serial data path.
• Maintenance: Details preventive maintenance, servicing of disk drives and power supplies, test equipment, adjustment procedures (including power supply and VCO adjustments), and troubleshooting techniques, including bootstrap error analysis.
• Maintenance Documents: Includes illustrated parts lists and schematic diagrams for the systems and modules.