This directly corresponds to the version number of a Phoenix BIOS. It was a significant release in the early-to-mid 2000s. To put it in perspective, the "6.00 PG" BIOS was commonly used for various motherboards and systems, and here are some specific technical details from the era:
Before searching for a download file, you must find out who actually manufactured your physical board. Definition of Phoenix BIOS | PCMag phoenix technologies ltd 600 pg bios update exclusive
