Osborne 1

Facts

  • Type: Portable computer
  • Manufacturer: Osborne Computer Corp.
  • Released: 1981
  • OS: CP/M 2.2
  • CPU:  Z80 @ 4 MHz
  • Memory: 64 KB RAM
  • Sound: 1 bit beeper
  • Video: 52 character x 24 line text mode
  • Monitor: 5″ monochrome CRT (external 12″ monitor available)
  • Ports: RS-232 compatible serial port, parallel port configurable as an IEEE-488 port
  • Storage: 2 x 5.25″ single-sided, single-density (dual-density upgrade available)
  • Weight: 10.7 kg (24.5 lb)
  • Dimensions: W:51 cm x D:32,5 cm x H:22,5 cm
  • Successor: Osborne Executive

Released 1981: The Osborne 1 is an early portable microcomputer, released on April 3, 1981 by Osborne Computer Corporation. However it’s not the very first portable computer, for example the IBM 5100 Portable Computer was introduced in September 1975, and predates it with almost six years.

It weighs 10.7 kg (24.5 lb), costed US$1,795 at introduction, and runs the CP/M 2.2 operating system. It’s powered from a wall socket as it has no internal battery. However, an external battery was later available and gave it an operational time for around one hour.

The computer shipped with a large bundle of software that was close in value to the machine itself, a practice adopted by other CP/M computer vendors. Competitors quickly appeared, such as the Kaypro II.

History
The Osborne 1 was developed by Adam Osborne and designed by Lee Felsenstein, first announced in early 1981. Osborne, an author of computer books decided that he wanted to break the price of computers. The computer’s design was based largely on the Xerox NoteTaker, a prototype developed at Xerox PARC in 1976 by Alan Kay. It was designed to be portable, with a rugged ABS plastic case and a handle. The Osborne 1 is about the size and weight of a sewing machine and was advertised as the only computer that would fit underneath an airline seat. It is now classified as a “luggable” computer.

Osborne 1 in my collection
Osborne 1 with boot screen, as seen in my collection

The Osborne 1 was described as “a cross between a World War II field radio and a shrunken instrument panel of a DC-3”, and Felstenstein admitted that carrying two of them to a trade show “nearly pulled my arms out of their sockets”. The computer nonetheless amazed observers; InfoWorld reported that “By far the most frequently asked question at” the West Coast Computer Faire “was, ‘What do you think of the new Osborne computer?'” BYTE Magazine wrote: “it will cost $1795, and it’s portable!” The word processing, spreadsheet, and other bundled software alone was worth $1,500; as InfoWorld stated in an April 1981 front-page article on the new computer after listing the included software, “In case you think the price printed above was a mistake, we’ll repeat it: $1795”.

West Coast Computer Faire attendees stated, InfoWorld said, that the Osborne 1 “represented an advancement of the price/performance ratio for microcomputers”. Adam Osborne agreed but emphasized the price, stating that its performance was “merely adequate”: “It is not the fastest microcomputer, it doesn’t have huge amounts of disk storage space, and it is not especially expandable.” Beyond the price, advertisements emphasized the computer’s portability and bundled software. The company sold 11,000 units in the first eight months of sales, and sales at their peak reached 10,000 units per month.

The Osborne 1’s principal deficiencies are a tiny 5 inch display screen, use of single-sided, single-density floppy disk drives which store 90KB per disk, and considerable unit weight. Adam Osborne decided to use single-sided disk drives out of concern about double-sided drives suffering head damage from rough handling. A single-density disk controller was used to keep costs down.

In September 1981, Osborne Computer Company had its first $1 million sales month. Sales were hurt by the company’s premature announcement of superior successor machines which replaced the Osborne 1’s 40 character screens with an 80 character screen such as the Osborne Executive, a phenomenon later called the Osborne effect. From 1982 to 1985, the company published “The Portable Companion”, a magazine for Osborne users.

Osborne 1

Remi Jakobsen


I'm collecting classic computers and video games, stretching from the 70's into the 90's. Restoration, history, usage ...


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