@roadriverrail @djsundog That was a competitor's product. I worked for InPhase, but I took a quick look at the wikipedia page. The InPhase approach did not include a servo layer on the disc. We were getting servo information from the recovery process itself (which is difficult when your read process is affected by temperature and humidity across multiple parameters). I have no idea how similar the chemistry of their storage medium was to ours, but the overall storage mechanism sounds similar.