DR11-K Interface User's Guide and Maintenance Manual

This document is a user's guide and maintenance manual for the DR11-K interface, a general-purpose digital input/output (I/O) interface designed for parallel transfer of up to sixteen bits of data between a PDP-11 Unibus computer and external devices.

The manual describes the DR11-K's functional areas:

1. Address Selection Logic: Determines which register is used and the type of data transfer.
2. Interrupt Control Logic: Manages program interrupts to the Unibus.
3. Device Interface Logic: Contains the Status Register, Input Register, and Output Register.

Key aspects covered include:

• Physical Description: The DR11-K is packaged on a single M7843 hex module and is highly configurable via solder jumpers and microswitches, allowing customization of input data paths, interrupt enabling, device/vector addresses, and control line polarity.
• Electrical Specifications: Details TTL-compatible input/output lines with protection and hysteresis for noise immunity.
• Software Interface: Explains how to program and interact with the DR11-K's registers, including methods for input and output programming and interrupt handling.
• User I/O Signals: Lists the 16 data lines and control signals (e.g., EXTERNAL DATA READY, INTERNAL DATA ACCEPTED, INITIALIZE) used for communication with external devices.
• Cabling: Provides guidance on connecting the DR11-K to external devices, including arrangements for long cables using distribution panels (H322).
• Theory of Operation: Delves into the detailed workings of the address selection, interrupt control, and buffer mechanisms.
• Installation and Checkout: Offers instructions for configuring the module and performing maintenance checks using a supplied loopback cable and diagnostic software.
• Application Examples: Illustrates various uses, such as interfacing with 15-bit or 16-bit devices, handling multiple input devices with interrupts, enabling inter-processor communication between two PDP-11s, and a specific interfacing example for the Coulter Model "S" Blood Counter.