It's not self-employment. It's royalty income. Enter it under "Rental Properties and Royalties." When TurboTax asks what type of royalty income it is, select "Other Intangible (Patents, copyrights)." The income and expenses will be reported on Schedule E (not Schedule C). You will not pay self-employment tax on the net income.
The TurboTax screens can be a little confusing because many of the screens are for both rental income and royalties. Read the screens carefully.
