Potential Problem in Early Revenue Version of CPU Chip

This document outlines a mandatory field change order (FCO KN20-AA-0001) for AlphaStation 600 systems with board revisions F01 or lower, shipped before September 1995. The update addresses a rare branch misprediction error found in early revenue 21164 (EV5) CPU chips. The mandated solution is to replace the existing system module with a revision H01 or higher module. The document provides detailed step-by-step instructions for authorized service technicians, including necessary safety precautions (using a static wrist strap), system preparation, module removal, installation of the new module and replacement PAL, safety label application, and post-installation configuration requirements using the ECU utility.