Osborne 1

Osborne 1 with opened keyboard

Serial RS -232 port with 1200 or 300 baud

The Osborne 1 was the first commercially available portable computer. Its inventor was Adam Osborne.


The computer was brought by the company Osborne Computer Corporation on the market in April 1981. The computer weighed 11 kg, which is why he mostly as a luggable computer, so as schleppbarer computer (German pun Schlepptop ) is referred to in comparison to later laptops in English. At the launch it cost 1,795 U.S. dollars in the United States. The introduction slogan was: " Our computer fit under any airplane seat. "

In the computer, a Zilog Z80 CPU working at 4.0 MHz, which was able to access a memory of 64 kB of RAM. The delivery was next to the operating system CP / M 2.2 and the MBASIC programming language. In design it was heavily based on the Xerox Taker at Xerox PARC, which was developed after the submission of a concept by Alan Kay in 1976 but never went into production.

In the foldable computer keyboard with 69 keys were ( keyboards today have about 100 ) and a 5 -inch diagonal screen with integrated, which could represent 24 lines of 52 characters.

Successor of the Osborne 1 was the Osborne Executive, before the manufacturer finally in September 1983 went bankrupt.


  • Two single-sided 5 ¼ " floppy drives with 40 tracks
  • Zilog Z80 CPU with 4 MHz
  • 64 kilobytes of RAM
  • 69 key keyboard
  • 5 -inch display, 52 -character × 24 line monochrome CRT monitor
  • IEEE -488 interface, for use as a printer port
  • Serial RS -232 port with 1200 or 300 baud, for external modems or serial printers


The Osborne 1 was delivered together with a package of application software. Its composition varied. Thus, the program dBASE II was not included in the first computer version.

The Osborne 1 in the film

The Osborne 1 is briefly seen in the movie The Philadelphia Experiment (1984). In the same scene we also see a Commodore 64