ThinkPad its 1992 launch to keep the Harvard Business School happy. In April 1992, IBM announced the first ThinkPad tablet computer at a news conference. The first ThinkPad tablet, a PenPoint-based device formally known as the IBM 2521 ThinkPad, was positioned as a developer's release. The ThinkPad tablet became available for purchase by the general public in October of the same year. In addition to giving it an innovative name, IBM marketed the ThinkPad through imaginative activities such as early customer pilot programs, numerous pre-launch announcements, and an extensive loaner program designed to showcase the product's strengths and weaknesses. IBM even
ThinkPad millionth unit of its ThinkPad line. Some Lenovo laptops (such as the X230, W530 and T430) block third-party batteries. Lenovo calls this feature "Battery Safeguard." It was first introduced on some models in May 2012. Laptops with this feature scan for security chips that only ThinkPad-branded batteries contain. Affected Thinkpads flash a message stating "Genuine Lenovo Battery Not Attached" when third-party batteries are used. The ThinkPad Yoga is an Ultrabook-class convertible device that functions as both a laptop and tablet computer. The Yoga gets its name from the consumer-oriented IdeaPad Yoga line of computers with the same form factor. The