What is IBM Multistation?

 IBM Multistation is the nickname of the personal computer (IBM itself was
 calling it with "the multiple function workstation".) for the business which IBM
 Japan, Ltd. developed individually.

 Age background
5150 (IBM ThePC) had already been put on the market, and it became a de-facto
    standard in a personal computer immediately after sale in the United States.

    Meanwhile a switchover from 8 bits to 16 bits began even in Japan, and 16 bits
    personal computer of the domestic production was on market starting with
    Mitsubishi Electric corp. (Multi-16) one after another with Hitachi (MB-16000),
    Fujitsu Ltd.  (FM-11) and NEC Corp. (PC-9801).

    IBM Japan also needed to put personal computers to the market too.
    However, in the personal computer of those days, unless it gave structure special
    to a Japanese display, sufficient processing speed was not obtained.

    Especially the big problem was the resolution of a display.

    Unless 16X16 dots per character can be found, a Kanji cannot be displayed
    Therefore, when 640X200 dots which is the resolution of CGA of IBM PC were
    used, only 12 lines has been displayed on one screen.

    By the Japanese maker, in order to display the Kanji of 25 lines, the video system
    with the resolution of 640X400 dots was developed.

    However, in IBM Japan, in order to display a Kanji by 24X24 dots, the video
    system of 1024X768 dots was developed.
    Moreover, in order even for the Kanji of 16X16 dots to give and display a margin,
    the video system of 720X512 dots was developed.

    And as a result, it became hardware unique to Japan.
    Multistation and IBM PC became non-compatibility.
    However, this poses a big problem later.

 With the appearance of the Multistation, details after that
    In 1983, IBM Japan introduced "The Multistation 5550" which is the model of
    beginning of a Multistation series.

    As series following "5550", "5540" as a low rank model and "5560" as a higher
    rank model were added.

    These models were mainly sold as an on-line terminal of the user who was using
    the Main-frame and Mid-range of IBM.

    But, as for Japan, a Japanese manufacturer occupied most market share.
    PC-9801 which NEC sold specially occupied most of that in the family use.
    When a personal computer was 8 bits, NEC and Fujitsu Ltd. and Sharp Corp.
    were fighting as 3 big manufacturers.
    After that was 16 bit, it had been 1 strong condition of NEC.

    IBM Japan competed with that, too, and sold 5510 (JX) which was the compatible
    machine of the PC Jr. for the family use.
    But, this ended in failure.
    IBM Japan and other Japanese manufacturers had market share with business
    use to a certain extent, too.
    However, it is a fact that there was a limit in the expansion of the market share,

    Then, it was made a problem that a Multistation and IBM PC were non-
    It did because it thought that it obstructed the expansion of the market share
    that hardware for IBM PC and software couldn't use it with a Multistation the
    personal computer of IBM.

    IBM proceeded with the development of PS/2 which a MCA bus was used for
    as the next-generation machine of PC/AT.
    IBM Japan were developed the next-generation machine of Multistation as
    the compatible machine of PS/2.
    And it was named PS/55.
    5570 which was the first MCA machine was put on the market in 1987.
    The general term of the series was changed from the Multistation to PS/55 at
    this time.
    5535 which was a lap-top model with 5530 of the lowest rank model was added
    as a Multistation at the same time.

    As for the new model following 5550-S/T/V after this, all became a MCA machine.
    Then, every time a MCA machine was on the market, the machines of the
    Multistation were put in order, and the machine of all the Multistations
    disappeared in 1991.

    Though this IBM continued the sales of PS/55 in this another day, it became
    IBM PC in the latter half in the 199's, and PS/55 disappeared.

    The sales of the MCA machine were stopped after that, too, and they became
    only the specifications of the PC/AT compatible machine.

  May, 2005 IBM transferred the personal computer enterprise to Lenovo, and
  has withdrawn it from the personal computer.

 The origin of the name of the Multistation
    As for the Multistation, "one unit 3 post", in other words
    A Personal Computer as to Japanese business
    Japanese word, processor
    The terminal of Japanese on-line system
    A function is changed by one unit, it can be used.

 At pays attention to the way of calling model name
    When 5570 was sold, the name of the series was changed to "The Personal
    System /55".
    The way of calling it settled in the head from this time became the same "PS/55"
    with the MCA machine, and came to give the person who didn't know a difference
    in two models confusion.

    Incidentally, each affiliated model of the Multistation is as the following.
      5550 A, B, C, D, E, G, H, J, K, M and P
      5560 G, H, J, K, M and P
      5540 B, G, J, K, M and P
      5530 G and H
      5535 M

    The model which L, N, R and the name of S, T, U, V, W, Y and Z are attached to is
    a MCA machine.
    Multistation seires and MCA machine series is perfectly non-compatibility of
    the hardware.