PCI Token Ring 1.0.1a2 provides a Token Ring Shim to provide backwards compatibility for legacy software which uses the slot manager API's which preceded the Open Transport networking architecture.
This software is posted in the Unsupported area of Apple Software Updates. These articles can help you locate the software update mentioned here:
Where To Find Apple Software Updates - Lists online services for free Apple software updates.
Obtaining Apple Product Support in the USA - Lists 800 numbers and online services for software updates, Apple support information, and a subset of the Apple Tech Info Library.