Laptops are usually shaped like a large notebook with thicknesses between 0.7–1.5 inches (18–38 mm) and dimensions ranging from 10x8 inches (27x22cm, 13" display) to 15x11 inches (39x28cm, 17" display) and up. Modern laptops weigh 3 to 12 pounds (1.4 to 5.4 kg); older laptops were usually heavier. Most laptops are designed in the flip form factor to protect the screen and the keyboard when closed. Modern 'tablet' laptops have a complex joint between the keyboard housing and the display, permitting the display panel to twist and then lay flat on the keyboard housing. They usually have a touchscreen display and some include handwriting recognition or graphics drawing capability.
The I.B.M. 5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype.
As 8-bit CPU machines became widely accepted, the number of portables increased rapidly. The Osborne 1 used the Zilog Z80, weighed 23.5 pounds (10.7 kg). It had no battery, only a tiny 5" CRT screen and dual 5¼" single-density floppy drives. In the same year the first laptop-sized portable computer, the Epson HX-20, was announced. The Epson had a LCD screen, a rechargeable battery and a calculator-size printer in a 1.6 kg (4 pounds) chassis. Both Tandy/Radio Shack and HP also produced portable computers of varying designs during this period. The first laptop using the clamshell design, used today by almost all laptops, appeared in 1982. The $8150 GRiD Compass 1100 was used at NASA and by the military among others. The Gavilan SC, released in 1983, was the first notebook marketed using the term "laptop".
Early laptops often had proprietary and incompatible system architectures, operating systems, and bundled applications, making third party hardware and software difficult and sometimes impossible to develop.