DR11-C General Device Interface User's Manual

This document is the User's Manual for the DR11-C General Device Interface, published by Digital Equipment Corporation (DEC) in September 1976.

The DR11-C is a general-purpose interface designed to connect a PDP-11 Unibus to an external peripheral device. It enables program-controlled parallel transfers of 16-bit data between the PDP-11 system and user devices, while also providing status, control, and interrupt functions.

Key features and contents of the manual include:

• Interface Components: Description of its three main logical sections: address selection logic, interrupt control logic, and device interface logic, which operate through three primary registers.
• Registers: Detailed explanation of the Input Buffer Register (DRINBUF) (read-only for device-to-Unibus data), Output Buffer Register (DROUTBUF) (read/write for Unibus-to-device data), and Control and Status Register (DRCSR) (for controlling interrupts, monitoring device status, and user-defined commands).
• Signals: Comprehensive listing and description of all user input/output signals, including data lines, control pulses (like NEW DATA READY and DATA TRANSMITTED), and request/control bits.
• Physical Description: Information on the DR11-C's packaging as a single M7860 quad module, its mounting options, power requirements, and connector details (Berg, M971, BC08R cables).
• Software Interface: Details on register, address, and vector assignments, and how the interface interacts with PDP-11 software, noting its software compatibility with the DR11-A.
• Applications: Examples of how the DR11-C can be used, including a basic interface, an interrupt-serviced interface (e.g., with an analog-to-digital converter), and its configuration as an interprocessor buffer to allow two PDP-11 systems to communicate.
• Maintenance: Mentions a supplied maintenance cable for self-checking of the interface logic.

The manual provides technical specifications, diagrams, and tables, including pin connections and timing details for various signals.