DUP11 Bit Synchronous Interface User's Manual

This user manual describes the DUP11 bit synchronous interface for PDP-11 computers.

The DUP11 is a synchronous line interface that enables data communication by performing parallel-to-serial and serial-to-parallel data conversion. It primarily supports the Synchronous Data Link Control (SDLC) and Digital Data Communications Message Protocol (DDCMP), including programmable SYN character recognition (also for BISYNC).

Key features and functionalities include:

• CRC (Cyclic Redundancy Check) computation and error detection.
• Handling of transparent data streams.
• Modem control logic and RS232-C interface.
• Hardware detection of flag characters and abort sequences.
• Interfacing with the PDP-11 via the Unibus using interrupt control for data transfer (without Direct Memory Access - DMA).

The manual provides comprehensive information on:

• Installation: Unpacking, pre-installation procedures, hardware verification, and setting up device and interrupt addresses.
• Operating Features: Detailed descriptions of modem control, transmitter, and receiver sections.
• Register Descriptions: In-depth explanations of the DUP11's programmable registers (e.g., control/status, data buffers) and their bit assignments, crucial for controlling data transmission, reception, and error handling.