UDA50

This document serves as a user guide for the UDA50 Disk Controller, a two-module system designed for the UNIBUS that can control up to four Standard Disk Interconnect (SDI) disk drives. It details the controller's functionality, installation procedures, diagnostic tests, and programming information.

Key aspects covered include:

1. Introduction and Overview: The UDA50 uses two processors (U for UNIBUS interface, D for SDI interface) and has an upgraded version (M7485/M7486 modules replacing M7161/M7162) offering enhanced performance, including increased RAM and selectable UNIBUS delays. A critical caution is provided regarding the incompatibility of old and new modules, requiring them to be replaced as a set. The controller utilizes the Mass Storage Control Protocol (MSCP) to simplify device-dependent requirements. Specifications for both old and new UDA50 modules are outlined.
2. Installation: A comprehensive step-by-step installation guide covers physically joining CPU and disk drive cabinets, preparing and installing the UDA50 modules (setting I/O page address switches, jumpers, and priority plugs), handling UNIBUS overloading, installing internal and external SDI cables via an I/O bulkhead, and selecting/preparing UNIBUS backplane SPC slots.
3. Diagnostics: The document outlines a three-part field acceptance test procedure: running UDA50-resident diagnostics (with LED error and symptom codes for troubleshooting), executing disk drive-resident diagnostics, and performing subsystem diagnostics tailored for both PDP-11 and VAX CPU systems.
4. Programmer Information: Specific details for software development are provided, including the octal addresses for the UDA50's IP and SA registers, the host-settable interrupt vector address, command limits, supported NPR burst values, exclusive support for 512-byte disk formats, and compatibility with both MSCP and diagnostic/utilities protocols.