IBM PC Convertible
The IBM PC Convertible is the first laptop computer released by IBM. Released on April 3, 1986, the Convertible was also the first IBM computer to use the 3.5" floppy disk which went on to become the industry standard. Like modern laptops, it featured power management and the ability to run from batteries.
It was the follow-up to the IBM Portable and was model number 5140. It was replaced in 1991 by the IBM PS/2 L40 SX, and in Japan by the IBM Personal System/55note, which was the predecessor to the ThinkPad.