This advertisement did not have a copyright notice and is in the public domain.
From the US Copyright Office Circular 3. Page 3, Contributions to Collective Works. (A magazine is a "collective work.")
A notice for the collective work will not serve as the notice for advertisements inserted on behalf of persons other than the copyright owner of the collective work. These advertisements should each bear a separate notice in the name of the copyright owner of the advertisement.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
This work includes material that may be protected as a trademark in some jurisdictions. If you want to use it, you have to ensure that you have the legal right to do so and that you do not infringe any trademark rights. See our general disclaimer. This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required.See Commons:Licensing.
Captions
Add a one-line explanation of what this file represents
{{Information |Description={{en|Logo and wordmark of Smoke Signal Broadcasting, a defunct computer company of the United States.}} |Source=Cropped from Smoke Signal Broadcasting Ad Dec 1977.jpg, itself a scan from page 53 of the December 1977 issue of ''Byte'' magazine by Michael Holley (Swtpc6800). |Date=1977-12 |Author=Smoke Signal Broadcasting |Permission= |other_versions= }} {{PD-US-no...