The Osborne 1, released in April 1981, was the first portable computer. It weighed 23.5 lbs (12 kg), cost US$1795 – just above half the cost of a comparable computer from other manufacturers – and ran the popular CP/M 2.2 operating system.
Besides being the first portable computer, the Osborne 1 was also the first computer that included software; the bundled WordStar, SuperCalc, dBase II, C-BASIC and M-BASIC had a retail value of more than $2,000. Its hardware features included dual 5¼-inch floppy disk drives, a 4 MHz Zilog Z80 CPU, a fold down keyboard, and a five-inch, 52×24-character monochrome monitor.
At its peak, Osborne Computer Corporation shipped 10,000 Osborne 1's per month. The computer was widely imitated as several other computer companies started bundling software, lowering prices, and offering portable computers. Osborne's most famous imitators was Kaypro, and later Compaq who offered a portable computer compatible with the IBM PC.