TURBOchannel DMA Reads and Conflicted I/O Writes

This document outlines FCO KN15-BA-0002 for DEC 3000 AXP Model 400 and 400S workstations. The issue involves a hardware conflict between TURBOchannel DMA reads and I/O writes that can cause the system to hang, requiring a hard reset. The resolution is to replace the existing system module (54-21149-02) with a newer revision (H09 or higher for D etch modules, or H10 or higher for F etch modules). The document provides detailed step-by-step instructions for authorized service personnel to remove the old system module and install the new unit supplied in the FCO kit, emphasizing electrostatic discharge (ESD) safety precautions.