IBM 5550 is a
personal computer
A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...
series that
IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
marketed in
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
,
Korea
Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...
,
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
and
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
in the 1980s and 1990s, for business use customers. In Japan, it was introduced in 1983 and promoted as "" 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.
General
The
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...
that had been marketed by
IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
since 1981, using
Intel 8088
The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers ...
, was not powerful enough to process the far eastern languages of Japanese, Korean and Chinese. Nor was the resolution of IBM PC's display high enough to show the complex characters of these languages.
The IBM 5550 was first introduced in Japan in March 1983,
using
Intel 8086
The 8086 (also called iAPX 86) is a 16-bit computing, 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-b ...
microprocessor and was called "Multistation 5550" because it had three roles in one machine: a
PC, a word processing machine which was traditionally marketed in Japan as a machine different from a PC, and an
online
In computer technology and telecommunications, online indicates a state of connectivity, and offline indicates a disconnected state. In modern terminology, this usually refers to an Internet connection, but (especially when expressed as "on lin ...
terminal.
After the Japanese 5550 models,
Korean
Korean may refer to:
People and culture
* Koreans, people from the Korean peninsula or of Korean descent
* Korean culture
* Korean language
**Korean alphabet, known as Hangul or Korean
**Korean dialects
**See also: North–South differences in t ...
,
Traditional Chinese
A tradition is a system of beliefs or behaviors (folk custom) passed down within a group of people or society with symbolic meaning or special significance with origins in the past. A component of cultural expressions and folklore, common examp ...
and
Simplified Chinese
Simplification, Simplify, or Simplified may refer to:
Mathematics
Simplification is the process of replacing a mathematical expression by an equivalent one that is simpler (usually shorter), according to a well-founded ordering. Examples include: ...
models were also introduced. IBM 5550 initially used its own architecture, but, later since 1987, was changed to use
IBM Personal System/2
The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM PC, XT, AT, and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART (serial p ...
's
Micro Channel Architecture
Micro Channel architecture, or the Micro Channel bus, is a proprietary hardware, proprietary 16-bit computing, 16- or 32-bit computing, 32-bit parallel communication, parallel computer bus (computing), bus publicly introduced by IBM in 1987 w ...
, being renamed as
Personal System/55.
In Japan,
Kiyoshi Atsumi
, born , was a Japanese actor. He is best known for portraying Tora-san in the Japanese comedy film series Otoko wa Tsurai yo, a role he played 48 times over 26 years.
Life and career
Atsumi was born in Tokyo suffering from childhood malnutr ...
, a film actor, was used to promote the 5550. IBM later introduced
IBM JX
The IBM JX (or JXPC) was a personal computer released in 1984 into the Japanese, Australian and New Zealand markets. Designed in Japan, it was based on the technology of the IBM PCjr and was designated the IBM 5511. It was targeted in the Austr ...
for home users in Japan, Australia and New Zealand, and
DOS/V
DOS/V is a Japanese computing initiative starting in 1990 to allow DOS on IBM PC compatibles with VGA cards to handle Double-byte character set, double-byte (DBCS) Japanese text via software alone. It was initially developed from PC DOS by IBM f ...
for both business and home users in Japan.
Features

The 5550 was originally planned as a terminal with a combination of word processing and personal computing targeted for Japanese computer market.
To display 24 dots
Mincho kanji
are logographic Chinese characters, adapted from Chinese family of scripts, Chinese script, used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese and are ...
typeface which was also used in many Japanese word processing machines, the 5550 had high
display resolution
The display resolution or display modes of a digital television, computer monitor, or other display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resoluti ...
such as a 1024×768 pixel graphic screen. The first model of 5550 was designed to read a display font from an external storage for multilingual support, including Chinese and Korean languages.

The 5550 fulfills three roles, via the following components:
* Japanese Business Personal Computer: .
* Japanese word processor: .
* Japanese online terminal: and .
The original Bunsho Program and emulators booted from a
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...
without Nihongo DOS. They used a proprietary disk format which couldn't be read from Nihongo DOS, so users had to replace floppy disks or set the boot partition to switch between two programs. Also, they had to use a conversion program to exchange data.
Later, they were ported for Nihongo DOS, and functions were gradually implemented. 3270 Kanji Emulation, 5250 Kanji Emulation and Bunsho Program were superseded by Nihongo 3270 PC in October 1983, Nihongo 5250 PC in September 1984 and DOS Bunsho Program in May 1986.
The first generation of IBM 5550 has up to three 5¼ inch '2DD' (720 KB) floppy drives because the Bunsho Program uses three floppy disks; program disk, font disk, and user data disk. Later models contain a font ROM card as other 1980's Japanese personal computers did.
Development
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
Austin refers to:
Common meanings
* Austin, Texas, United States, a city
* Austin (given name), a list of people and fictional characters
* Austin (surname), a list of people and fictional characters
* Austin Motor Company, a British car manufac ...
office in 1980, and the
IBM Personal Computer
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on August 12, 1981, it was created by a ...
developed in
Boca Raton
Boca Raton ( ; ) is a city in Palm Beach County, Florida, United States. The population was 97,422 in the 2020 United States census, 2020 census and it ranked as the 23rd-largest city in Florida in 2022. Many people with a Boca Raton Address, ...
office, but it was difficult to combine different types of machines.
Considering price–performance ratio and continuity of an architecture, the team examined not only Intel's but also other manufacturer's processsors. 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
Text wrapping, also known as line wrapping, word wrapping or line breaking, is breaking a section of text into lines so that it will fit into the available width of a page, window or other display area. In text display, line wrap is continuing on ...
.
For personal computing, Nihongo DOS K2.00 had been developed by Microsoft. It was the second Japanese localization of MS-DOS 2.0 followed to Toshiba's PASOPIA 16. Nihongo DOS bundled the
Microsoft BASIC
Microsoft BASIC is the foundation software product of the Microsoft company and evolved into a line of BASIC interpreters and compiler(s) adapted for many different microcomputers. It first appeared in 1975 as Altair BASIC, which was the first v ...
interpreter which designed for the 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 its 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
is a Japanese multinational electronics manufacturer, headquartered in Kadoma, Osaka, Kadoma, Japan. It was founded in 1918 as in Fukushima-ku, Osaka, Fukushima by Kōnosuke Matsushita. The company was incorporated in 1935 and renamed and c ...
, printers by
Oki Electric Industry
, commonly referred to as OKI, OKI Electric or the OKI Group, is a Japanese information and communications technology company, headquartered in Toranomon, Minato-ku, Tokyo and operating in over 120 countries around the world.
OKI produced the f ...
, and keyboards by
Alps Electric
, previously known as is a Japanese multinational corporation, headquartered in Tokyo, Japan, producing electronic devices, including switches, potentiometers, sensors, encoders and touchpads.
The company was established in 1948 as Kataoka El ...
.
Models
* 5551-A/B/C/D/E/G/H/J/K/M/P (Basic models, placed beside the display. Later became a smaller size like 5540)
* 5541-B/E/J/K/M/P (Smaller size models, on which the display can be placed. Later made even smaller)
* 5561-G/H/J/K/M/P (Larger size models, all models employ
Intel 80286
The Intel 80286 (also marketed as the iAPX 286 and often called Intel 286) is a 16-bit microprocessor that was introduced on February 1, 1982. It was the first 8086-based CPU with separate, non- multiplexed address and data buses and also the f ...
)
* 5530-G/H (Stand-alone models, without the communications adapter. Used 3½ inch floppy disk)
* 5535-M (Laptop, using 3½ inch floppy disk)
Competition
In Japan, Multistation 5550 competed against:
*
Fujitsu FACOM 9450 and
FMR series
*
NEC PC-9801
The , commonly shortened to PC-98 or simply , is a lineup of Japanese 16-bit and 32-bit Personal computer, personal computers manufactured by NEC from 1982 to 2003. While based on Intel processors, it uses an in-house architecture making it inc ...
series and
N5200/5300 series
Reception
''
BYTE
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...
'' in 1983 speculated that "we may soon see a similar machine here in America". Describing the 5550 as "a true workstation", the magazine envisioned the computer as filling the "considerable gulf above the PC", and a rival to the
IBM System/36
The IBM System/36 (often abbreviated as S/36) was a midrange computer marketed by IBM from 1983 to 2000 - a multi-user, multi-tasking successor to the System/34.
Like the System/34 and the older System/32, the System/36 was primarily prog ...
minicomputer. It praised the 5550's "unprecedented" combination of
kanji
are logographic Chinese characters, adapted from Chinese family of scripts, Chinese script, used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese and are ...
support with high-end word-processing capability, and reported that in Japan an ecosystem of vendors providing products for the computer was forming. The magazine concluded that "if the American PC is any precedent, the market should soon be filled with 5550 software".
The 5550 was primarily sold for large enterprises who used IBM's mainframe computer.
Meiji Life who used the
IBM 3081
The IBM 308X is a line of mainframe computers, of which the first model, the Model 3081 Processor Complex, was introduced November 12, 1980.IBM used a capital X when referring to 308X, as did others needing an official reference; see the Congressi ...
mainframe decided to purchase about 500 units of the 5550 in 1983. A manager of its System Development section said, "IBM supports us to satisfy our demand for the communication software. We are planning to replace all of our IBM terminals. A new personal computer must respond for the host computer as fast as a terminal, and it must have various communication softwares."
In Japan, the 5550 had annual sales of 70,000 units in 1985, and the Nikkei Personal Computing magazine reported in 1986 that the 5550 had the largest personal computer share of 30% in the corporate sector.
Timeline
See also
*
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...
,
IBM PC/AT
The IBM Personal Computer AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 8028 ...
and
IBM PS/2
The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM Personal Computer, IBM PC, IBM Personal Computer XT, XT, IBM Personal Computer/AT, AT, and IBM PC Convertible, PC Co ...
*
IBM JX
The IBM JX (or JXPC) was a personal computer released in 1984 into the Japanese, Australian and New Zealand markets. Designed in Japan, it was based on the technology of the IBM PCjr and was designated the IBM 5511. It was targeted in the Austr ...
,
AX architecture and
DOS/V
DOS/V is a Japanese computing initiative starting in 1990 to allow DOS on IBM PC compatibles with VGA cards to handle Double-byte character set, double-byte (DBCS) Japanese text via software alone. It was initially developed from PC DOS by IBM f ...
*
List of IBM products
The list of IBM products is a partial list of products, services, and subsidiaries of IBM, International Business Machines (IBM) Corporation and its predecessor corporations, beginning in the 1890s.
Context
Products, services, and subsidiari ...
References
External links
*
Introducing Multistation 5550(describes the models in detail)
{{DEFAULTSORT:Ibm 5550
5550
Computer-related introductions in 1983