Based on the keywords in your request, you are likely referring to a legacy Allen-Bradley/Rockwell Automation software distribution, specifically RSLogix 500 (often associated with catalog number 9324-RLD or similar, where "81000" might refer to a specific legacy part or serial batch) using a Master Disk for copy protection.
Most users searching for this keyword are actually searching for a solution to an activation problem. Here is how the Master Disk works for CPR9: rslogix 500 81000 cpr9 w master disk
RSLogix 500 version 8.10.00 (CPR 9) represents a major transitional phase for Rockwell Automation’s legacy PLC software, serving as the bridge between the old EVRSI (Master Disk) activation and the modern FactoryTalk Activation systems. Core Technical Profile Based on the keywords in your request, you
RSLogix 500 version 8.10.00 (CPR 9) is a critical transitional release in the history of Rockwell Automation's programming software for the SLC 500 and MicroLogix controller families. Released around 2008, it serves as the bridge between legacy physical activation and modern digital licensing. Key Specifications & Features Core Technical Profile RSLogix 500 version 8