Obsolete mechanical formats form a major part of archives' holdings. Once a format has passed into obsolescence, there is virtually no commercial development in replay facilities, and the system as such dies. The paper discusses the fundamental principles of mechanical recording and replay as well as the latest construction for replaying historical discs and cylinders, commercial and noncommercial. An addendum gives simple instructions to the archive having only an occasional need to replay historical formats.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.