page_title: IBM 5550
section_title: Development
hierarchical_section_title: IBM 5550 / Development
caption_attribution_description: Nederlands: IBM Display Writer System uit 1980
context_page_description: IBM 5550 is a personal computer series that IBM marketed in Japan, Korea, Taiwan and China in the 1980s and 1990s, for business use customers. In Japan, it was introduced in 1983 and promoted as "Multistation 5550" because it had three roles in one machine: a PC, a word processing machine which was traditionally marketed as a machine different from a PC in Japan, and an IBM-host attached terminal.
context_section_description: Yu Kawara (川原 裕) of IBM Fujisawa Development Laboratory planned the terminal with a combination of word processor and personal computer, called the Multi-functional Workstation, and he proposed it at the headquarter in March 1981. The development team was founded as an Independent Business Unit (IBU).
  The team set goals for IBM 5550 that the machine was usable for both word processing and personal computing on the same architecture at least 3-5 years. They tried to build the 5550 from the IBM Displaywriter System 6580, the English word processor developed in Austin office in 1980, and the IBM Personal Computer developed in Boca Raton office, but it was difficult to combine different types of machines.
  Considering price–performance ratio and continuity of an architecture, the team examined processors chosen from Intel's and other manufacturers. The IBM PC used an Intel 8088, but the 5550 employed an Intel 8086 because bus speed largely influenced for performance of the machine which had high display resolution.
  To gain an advantage over competitors in Japanese word processing, 24 pixel font models render characters in a box of 26×29 pixels, and the total display resolution is 1066×725 pixels calculated with box width by 41×25 text. 16 pixel font models render characters in a box of 18×21 pixels, and the total display resolution is 738×525 pixels. The 5550 had one more column than 40 columns of usual Japanese computers, which enabled line breaking.
  For personal computing, the Nihongo DOS K2.00 had been developed by Microsoft. It was a Japanese localization of MS-DOS 2.0 followed to Toshiba's PASOPIA 16. The Nihongo DOS bundled the Microsoft BASIC interpreter specialized for IBM 5550. Programming languages and the Japanese version of Multiplan were also provided.
  The team didn't consider the machine was used for online communication, but they realized its importance during the development. They decided to add a role of a terminal in January 1982. This change extended the development term. In May 1982 Business Show (one of computer industry exhibitions in Japan), IBM Japan only displayed the IBM PC as a reference material. They unveiled the development of 5550 in fall 1982.
  IBM Japan didn't have a factory for mass production of personal computers, so the production of 5550 was outsourced to some companies. System units, hard disks, and monitors were manufactured by Matsushita Electric Industrial, printers by Oki Electric Industry, and keyboards by Alps Electric.
caption: IBM Displaywriter System
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