SEIKO UC-2000 (1984) – the dawn of wearable computers

Seiko UC-2000 wristwatch computer 6

SEIKO UC-2000 (1984) – the dawn of wearable computers

If you deem your new smartwatch the most futuristic piece of technology around, better you have a look at this strange thing dating back to the good old Eighties.
It’s the UC-2000, a wristwatch wearable computer introduced in 1984 by well-known Japanese tech company and watchmaker Seiko.

The first Seiko wrist computer

The basic object (the watch) was more a programmable calculator than a true PC, but things changed when it was coupled with the UC-2200 dock station. This was a quite unconventional device – provided with a small thermal printer, a keyboard, 4 KB of RAM, and a 26 KB ROM which included a Microsoft Basic programming software, a Japanese / English translator, and some games – through which the watch could be programmed and turned into a portable PC, albeit rather limited in its functions.
The docking station could also be connected to a desktop computer to exchange data to and fro the “watch”.

The Seiko UC-2000 was equipped with a 50×28 pixels monochrome LCD screen, admittedly not the best if you are passionate about high-res video games.
When not docked, the wrist computer was controlled through four large (well, reasonably large) buttons, two of which were used to play the basic video games which ran on the device.

During the ’80s, Seiko (and its subsidiary Epson) released improved versions of the watch, some of which could be directly connected to various PCs (including Apple II, Commodore 64, and IBM PC) through an RS232 interface cable, thus removing the need of a docking station; a 1985 model, the Epson RC-20, was even equipped with a touch-screen (does this remind you something?) and, at least at a first sight, looks remarkably similar to a modern smartwatch.
Yet, none of them ever achieved the success the company expected, and the glorious era of the Japanese wrist computers came to a premature end in the second half of the ’80s (at least for the time being).

Seiko UC-2000 wristwatch computer 1

A Seiko UC-2000 on its docking station UC-2200, note the thermal printer of the right and ROM pack on the left

Seiko UC-2000 wristwatch computer 8

Seiko UC-2000 wristwatch computer 4

Seiko UC-2000 wristwatch computer 5

Seiko UC-2000 wristwatch computer 10

Original Japanese and Canadian advertisements of the Seiko UC-2000

Seiko UC-2000 wristwatch computer 7

The LCD dot-matrix display and the main board of the UC-2000, equipped with a 4 bit CPU running at 32 kHz, 2 KB of RAM, and 7.5 KB of ROM. Source:

Black Moon Rising Seiko UC-2000 computer

The UC-2000 also had an ephemeral career in Hollywood, as a futuristic device Tommy Lee Jones wears in the (admittedly unimpressive) 1986 action film Black Moon Rising. Video still by Simon

EPSON RC-20 wrist watch computer

The Epson RC-20 (1985), possibly the first touch-screen wearable computer

Apple Watch

A modern touch-screen smartwatch, the Apple Watch (2015), Image courtesy of Apple

The Japanese way: wrist and pocket computer of the ’80s

Wristwatch computers were possibly the epitome of the quest for miniaturization about which Japanese electronics manufacturers (such as Seiko/Epson, Sharp, and Casio) were caring so much in the ’80s.
Indeed, while in the same period American and European high-tech companies (with the exception of Texas Instruments and HP, possibly) were mostly interested in expanding the computational power and the graphical user interface of personal computers, at the cost of building rather large and heavy machines, Japanese ones focused on producing less capable devices, yet as small and lightweight as they could.

A typical pocket PC of the time, such as the Sharp PC-1500, weighted few hundreds of grams, almost nothing when compared to the dozens of kilograms of a typical coeval desktop PC; although the two were not comparable in terms of display size, graphics, speed, available software, and output peripherals, of course.

All such Japanese ultra-micro-computers, including the Seiko UC-2000/2200, shared similar hardware, which included either a power-saving CMOS version of popular CPUs such as the Zilog Z-80 and the Intel 8086 or proprietary microprocessors such as the Hitachi SC61860, a dot-matrix LCD display, and an internal ROM memory (so without magnetic mass memory units, although external cassette tape memory devices were usually available in order to expand the very limited space provided by the internal ROM chips, which usually didn’t exceed few KB).
Almost all pocket computers were provided with one of the many versions of BASIC available at the time, with some of them also capable to run more powerful programming languages such as Assembly, and even C.

Retrospectively, many of those projects can be considered the predecessors of products widely popular today, such as smartwatches, laptops, and Tablet PCs. The reasons why they didn’t succeed can be found in their poor graphics performances – mostly due to the limitations of the LCD technology of the time -, and in the little capacity of their ROM circuits to store a decent amount of data, which required to connect all those pocket and wrist PCs to some kind of external mass memory unit to make them somewhat usable.
Yet, machines such as the Epson HC-20 can be reputed as the “transitional fossil” between pocket PCs and modern portable computers.


Seiko TV watch

Seiko TV Watch James Bond Octopussy

Though not a computer, the Seiko TV Watch (1982) was a remarkable piece of technology at the time (even if it required an external TV tuner) of which Roger Moore / James Bond makes wide use in Octopussy (1983) although in a “customized by Q” color-display version (the original featured a monochrome LCD display)

Sharp PC 1500 pocket computer

A Sharp PC-1500A pocket computer (1982) with a CE-150 Printer and Cassette Interface. Photo courtesy of

EPSON HX-20 portable computer 2

The Epson HX-20 portable computer (1981), possibly the first laptop in history.

Nevertheless, if only LCD and ROM technology would have been slightly more developed in the early ’80s,  we could all live now in an “alternate reality” in which the symbol of the world’s largest computer manufacturer is a Japanese persimmon instead than an American apple…

think different alternate reality

Pieces of an alternate reality…. (the man in the picture is Shinji Hattori, CEO of Seiko). The image is a fake advertisement made by me, of course..;)

Further reading

Technical specs and a teardown of the UC-2000 are available at:

An article describing various models of Seiko’s wrist computers and calculators is here:

Watch the UC-2000 in action in this vintage video

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Visionary computer designs of the past

Visionary computer designs of the past

Visionary computer designs of the past

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