Will SCMS prevent me from making copies?

SCMS is the Serial Copy Management System. The goal is to allow consumers to make a copy of an original, but not a copy of a copy. Analog recording media, such as audio cassettes and VHS video tape, degrades rather quickly with each successive copy. Digital media doesn’t suffer from the same degree of generation loss, so the recording industry added a feature that has the same net effect.

SCMS will affect you if you use consumer-grade audio equipment. Professional-grade equipment and recorders that connect to your computer aren’t restricted.

The system works by encoding whether or not the material is protected, and whether or not the disc is an original. The encoding is done with a single bit that is either on, off, or alternating on/off every five frames. The value is handled as follows:

Unprotected material: copy allowed. The data written is also marked unprotected.

Protected material, original disc: copy allowed. The data written will be identified as a duplicate.

Protected material, duplicate: copy not allowed.

If you’re using a consumer audio CD recorder, SCMS will prevent you from making copies of copies of protected material. It will not prevent you from making a copy of an original disc you have purchased, and it won’t stop you from copying unprotected discs.

Knowledge Base