DR11-W Direct Memory Interface Module User's Guide

This document is the User's Guide for the DR11-W Direct Memory Interface Module (M8716), published by Digital Equipment Corporation (DEC).

The DR11-W is a general-purpose UNIBUS Direct Memory Access (DMA) device designed for DEC's PDP-11 and VAX computer systems. Its primary functions include:

• Interfacing user devices to the UNIBUS.
• Establishing interprocessor links between PDP-11 and VAX systems.
• Providing a UNIBUS to Q-Bus system link when connected to a DRV11-B module.

The module supports various data transfer modes, including programmed I/O, interrupt operations, and DMA transfers (word, block, and burst modes), and can transfer up to 64K 16-bit words. It operates in two modes: DR11-B compatibility mode and an enhanced DR11-W mode (which adds error monitoring and interprocessor link capability).

The guide provides comprehensive information on:

• Its functional description, physical layout, and performance specifications.
• Details of its software interface, covering programmable registers like the Word Count Register (WCR), Bus Address Register (BAR), Input/Output Data Register (IDR/ODR), and Control and Status Register/Error and Information Register (CSR/EIR).
• Descriptions of I/O signals and their timing.
• The theory of operation for programmed data transfers, interrupt operations, and DMA.
• Interfacing and programming considerations, including examples for VAX and PDP-11 systems.
• Installation procedures and acceptance testing.
• Specifics of its use in interprocessor link configurations.
• Available diagnostic programs for maintenance.