Digital UNIX / PALcode Revision Notification (for certain Digital UNIX Systems)

This document notifies Digital UNIX system users about a problem affecting Alpha systems running PALcode revision 1.45 or greater with Digital UNIX versions prior to V3.2F. Newly received systems are not affected due to factory-installed V3.2F+ software or pre-applied patches. However, users who choose to re-install Digital UNIX from a media kit with an affected combination (UNIX < V3.2F and PALcode >= V1.45) will experience issues.

The problem specifically impacts applications performing IEEE floating-point operations, leading to console messages like "unknown OPDEC from ieee emulation" or "Illegal instruction (core dumped)". Users can verify their PALcode version using the uerf -R command.

Two workarounds are provided:

1. Applying a software fix (patch) available from Digital Customer Support Centers since May 1996. Specific patch IDs are listed for Digital UNIX V3.2C, V3.2D-1, and V3.2D-2.
2. For systems other than AlphaStation 255, replacing the current PALcode with a previous version.

The document strongly recommends implementing one of these workarounds if affected before putting the system into normal operation. Contact information for U.S. and non-U.S. customer support centers is also provided.