I/O, October 1980 issue, featuring the Rubik's Cube. This is an old magazine stored at home. There is age-related deterioration (stains, yellowing, discoloration, and page folds on the body, cover, edges, etc.), but there is no problem with reading the text. I have flipped through it and found one page with writing, but I don't think there are any markings or missing pages. Please understand if there are any. Please consider the photos for reference. Thank you for looking.