Ardent Tool of Capitalism

Type 5550

Introduction
Box Models
Desktop Models

Content created by "Mr. Tahara" (mirror HERE and HERE). Edited by Tomáš Slavotínek.

Introduction

The 5550 machines sit at the heart of the Multistation series. Many machines carrying this model number were released — from the premiere IBM 5550 Multistation model back in 1983 to the discontinuation of the PS/55 series.

The A to K models have an unique box-like form factor. The later M/P models (introduced after the MCA-based 5570) come in a desktop enclosure. The A to H models use the i8086 processor, J and onward use the i80286.

There were a few models intended for export to the United States, Taiwan and South Korea.

Box Models

5551-A/B/C/D/E/G/H

5551-J/K

The inside is divided into three portions, the substrate, the drive, and the slot. Photo of the internals HERE.

Note: The list includes some models that were not covered by the available IBM documentation (see entries with "unknown" price). The information pertaining to these models may not be entirely accurate. Specifically:

• Models A, B, C, and G - some information was extrapolated from the model number
• Model F - no info other than the model name, so all the details are unknown
• Model Y - same as F, details are based on the Dec 1984 anno. date and the model number
• Taiwanese/Korean models - no information other than the model name (found on the web)

Memory

In KDOS, the memory above 1 MB can be used only as a RAM disk.
In OS/2, all memory can be used for programs.

Floppy Drives

2DD is 720KB (640KB initially)
2HC is 1.2MB

Up to 3 floppy drives can be installed, except for the models with a hard drive.
Later, an external 3.5-inch drive for media conversion could be added.

Video Modes

Displays with 16-dot characters have a resolution of 720x512 pixels.
Displays with 24-dot characters have a resolution of 1024x768 pixels.

The C model displays 4 out of 16 colors @ 360x512 pixels. However, the system guide mentions a "new model C" (C1x?), which can display 16 out of 64 colors @ 720x512. The subsequent models are 16-dot and 24-dot types with 16 out of 64 colors.

Kanji Characters

Kanji fonts are loaded from software if the optional Kanji font card isn't installed. The Kanji font card is required for models with only one floppy drive. (Ed. Depending on the operation mode, the font card may not be required.)

Export Models

In addition to English, the software catalog lists operating systems in Hangul, Simplified Chinese, and Traditional Chinese.

It seems that IBM Korea was manufacturing a Multistation for Hangul. However, the G model mentioned above may be made in Japan. It is unknown whether China and Taiwan was also producing.

Dimensions

Width: 261 mm
Depth: 410 mm
Height: 305 mm

Desktop Models

* Kanji font ROM is standard equipment for all models

Memory

In KDOS, the memory above 1 MB can be used only as a RAM disk.
In OS/2, all memory can be used for programs.

Floppy Drives

An external 3.5-inch drive for media conversion can be added.