DEC-10-IACB-D DA10 PDP8 9 Interface System Description Sep69

The DA-10 Interface Unit is an optional component for the Digital Equipment Corporation (DEC) PDP-10 System, designed to enable bidirectional data and control information transfer between a PDP-10 processor and either a PDP-8 or a PDP-9 processor.

Key Functions and Features:

• Word Length Conversion: The DA-10 addresses the differing word lengths of the processors: it assembles 12-bit words (from PDP-8) or 18-bit words (from PDP-9) into 36-bit words for the PDP-10, and conversely divides 36-bit words from the PDP-10 into the appropriate 12-bit or 18-bit segments for the connected peripheral processor.
• Data Buffers: It incorporates two 36-bit buffers: FM10 (for data from PDP-10) and TO10 (for data to PDP-10), along with status flags to manage data flow (e.g., FULL, EMPTY flags).
• Operation: Data transfers are initiated by specific I/O instructions (DATAO/DATAI for PDP-10, IOT instructions for PDP-8/9). The DA-10 generates Program Interrupt Requests (PI RQ) to signal the respective processors about buffer status.
• Configurability: The unit can be configured during installation via jumper networks (pulse mixers) to be compatible with either a PDP-8 or a PDP-9, adapting the data transfer pulses and byte segmentation accordingly.
• Physical Design: It is housed in a standard 19-inch cabinet (Type CAB-9B) and comes in 60 Hz (DA10A) and 50 Hz (DA10B) configurations. It includes an indicator panel to display buffer contents and status, and a power control panel.
• Maintenance and Diagnostics: The document provides procedures for preventive maintenance, corrective troubleshooting using a dedicated diagnostic program (MAINDEC-10-D8A0-D) which includes a self-check mode (without PDP-8/9 connection), and guidelines for repair and parts replacement.

The document serves as a comprehensive guide for installation, operation, programming, and maintenance, assuming the reader has familiarity with DEC logic and the general operations of the PDP-8, PDP-9, and PDP-10 processors.