PowerBook 140 (1991)

The PowerBook 140 was released along with the PowerBook 100, 140, and 170—three new Macintosh laptop models that were mobile in addition to being portable. The lineup replaced the Macintosh Portable, a very bulky device that weighed in at 16 pounds and was 4 inches thick.

The PowerBook 140 featured a 16 MHz 68030 processor, 2 MB or 4 MB of RAM, a 20 MB or a 40 MB hard drive, and an internal 1.44 MB floppy drive. The screen measured 9.8 inches in a monochrome passive-matrix display.

Unlike Macintosh computers at the time that were controlled by a mouse, the built-in input device on the PowerBook 100-family laptops was a trackball with an upper and lower button. Each button had the same function and two were provided for the benefit of ergonomics for the user to select which to use. 

The introductory price for this laptop was $3,199.

Source: EveryMac.com