The BTRON subproject, as is well known, is one of the not so successful subprojects of the TRON Project. Not only did it experience massive foreign political influence aimed at derailing it, it also suffered from internal disagreements between the designers of the specifications and the implementers of the specifications. Amazingly, in spite of all the setbacks it has suffered, the BTRON subproject developed a unique personal computer architecture that survives to this day in the form of Cho Kanji V and PMC T-Shell, the former aimed at ordinary end users and the latter aimed at embedded system developers. Both of these are available for purchase from Personal Media Corporation.
The history of the implementation of BTRON specifications began in the latter half of the 1980s when a special development team from Matsushita Electric Industrial Co.'s Information Research Research Laboratory, started development of a BTRON-based educational computer in response to requirements set by the Center for Education Computing. The team was led by Yoshiaki Kushiki, a graduate of Kyoto University. His right-hand men were Masahiro Shimizu and Kazuo Kajimoto, who were likewise graduates of Kyoto University. Other key members of the development team were Yoshihiko Imai, Masaaki Kobayashi, and Makoto Ando.
There were some major disagreements between Prof. Ken Sakamura and the Matsushita team. For example, Prof. Sakamura wanted the first implementation of the BTRON subarchitecture, officially called "µBTRON" , to be based on a Motorola 68000 microprocessor, the same microprocessor that powered that Apple Computer Inc.'s Macintosh computer, but Matsushita decided to implement it on top of existing Intel 80286-based hardware already under production at their company. Second, Prof. Sakamura wanted the Matsushita team to closely follow the BTRON specification, but the Matsushita team eventually loosely applied the specification, which is why the educational computer it eventually developed has to be described as BTRON-based, rather than BTRON-specification.
After the Office of the United States Trade Representative targeted the BTRON and CTRON subprojects for derailment, demonizing them as "market interference," Matsushita slowly lost interest in BTRON, although it did eventually market to schools its PanaCAL ET educational computer, which uses an operating system called ET Master. Unbelievably, after Matsushita ended its involvement with the BTRON subproject, Matsushita got deeply involved with the development and propagation of real-time Linux, which is one of ITRON's rivals, and Kushiki went on to become a major figure in the introduction and promotion of the Linux kernel for embedded systems in Japan.
With the departure of Matsushita from the implementation of BTRON specifications, the job of implementing BTRON specifications fell on the shoulders of Personal Media Corporation, a tiny software house in Tokyo that has strong links to the University of Tokyo, which was working on an implementation of the 2B specification. In fact, its current CEO is none other than Akira Matsui, who was one of Prof. Sakamura's best students at the University of Tokyo, and has played a leading role in the development and implementation of the BTRON subarchitecture. The other luminary at Personal Media is Tatsuya Izumina, a very talented software engineer around whom the company was founded in 1980. The company itself started out developing software for personal computers, producing the first card database for personal computers in Japan called "Airisu." The company's bread and butter product is a tax preparation software application that runs on IBM-PC/AT-compatible computers.
One of the biggest problems Personal Media faced when taking over the development of BTRON from Matsushita was that BTRON was developed on top a 16-bit dead-end microprocessor, the Intel 80286. All sorts of compromises had to be made to implement the BTRON specification on top of that architecture, and that made it more difficult to reimplement the operating system on top of the Intel 80386 microprocessor, but eventually Personal Media succeeded. Moreover, they continued to add new features, such as an unabridged character set, the MicroScript visual programming language, a Web browser, and an electronic mail application. Considering how small the company is, it is amazing that it has been able to steadily evolve the operating system into something useful to people in many fields. More than anything else, people are impressed by its fast startup and shutdown speed, which is why it is used in various T-Engine-based products, such as the Ubiquitous Communicator and handheld terminals.
Personal Media's Achilles heel is the fact that it is particularly challenged in the area of marketing. Not only does the company have trouble marketing internationally, it even has trouble marketing domestically, which is why there still aren't that many BTRON users even in Japan. In fact, large numbers of Japanese have still never heard of BTRON. The reason for this is quite simple to understand. The company was set up by, and has been run by highly talented technology guys, who naturally know more about software engineering than marketing. So just like Steve Wozniak's CL 9 and Paul Allen's Asymetrix, both of which were likewise set up by technically savvy folks who were not particularly gifted in the area of marketing, the company has only been able to achieve modest success, in spite of the fact that it has a good product.
That leads the casual observer to the big what-if--what if a guy who was great at marketing, a Steve Jobs or a Bill Gates, became the CEO of Personal Media, or got permission from Personal Media to sell BTRON internationally. Well, that actually happened in 1999, when Sennet, Inc. came into existence. Sennet was set up by Yoshito "Super" Yamaguchi, a former Mitsubishi Electric Corporation executive who held various high ranking positions in the company over a long career, to market the BTRON3-specification Cho Kanji operating system worldwide via a U.S. affiliate called Global OS Corporation. In spite of the fact that Sennet developed both English and Chinese language versions of the operating system and had the modest goal of developing appliances, it eventually failed because it was unable to attract enough venture capital.
After the T-Engine project was launched in 2002, it became clear that personal computing devices could be rapidly developed and marketed. This is because the project had developed a huge family of standardized hardware platforms; a single source, standardized, real-time kernel; and it even had a standardized external kernel and human-machine interface in the form of PMC T-Shell. One company that decided to take advantage of these technologies to develop an advanced educational computer was PIN CHANGE Co., Ltd., which was set up with capital from none other than Matsushita Electric Industrial Co. Even more astounding, the educational computer they developed was the spitting image of Alan Kay's Dynabook. Kazuhiro Kayashima described its development at TRON SHOW 2003, and then as suddenly as it appeared, it disappeared, never to be marketed to Japanese schools.
This second go at an educational computer by Matsushita is one of the most intriguing incidents in the history of the TRON Project. What happened? Did Matsushita receive a call from the U.S. government telling them to back off or face severe consequences? That's not beyond the U.S. government. Just consider the fact that the U.S. government put strong pressure on the government of Japan not to abandon nuclear power in spite of the massive Fukushima nuclear accident in which four U.S.-designed reactors blew up. Did Kushiki and the other proponents of the Linux kernel at Matsushita win an internal power struggle? That's entirely possible, since he seems to have successfully climbed to a very high position within the company. Hopefully, one day after everyone has retired, someone will tell all. Whatever the case, another monkey wrench was thrown into the gears of the BTRON subproject, and another chance for mass marketing was lost.
The BTRON subproject has also produced some interesting characters. One of them was Takayoshi Umehara, who was the planning department chief in the information systems headquarters of Japan Airlines. In April 1987, even before the first BTRON machine was shown to the world, he started a JAL BTRON study group within the company. The goal of the study group was to use BTRON to create a computer reservation system that would give the company a leg up in competition, and the results were unveiled in 1989 . Another interesting character was Mineyuki Kimoto, who we have already met among the ITRON personalities. Not only did he master ITRON, he became a developer and writer for the BTRON subarchitecture. He even participated in meeting of the B-Free project, which aimed to create an open source BTRON-specification operating system. A third person of interest in the BTRON subproject is Kaoru Misaki, who specialized in writing about the TRON Project in general, and BTRON in particular. He also directly helped the development of BTRON application software.
 The operating system that was later created for the BrainPad TiPO personal digital assistant was also called µBTRON, which is a little confusing. However, in terms of architecture, the two are separate and distinct.
 The JAL BTRON reservation system was described in TRONWARE Vol. 6, pp. 125-132. Unfortunately, the article is written in Japanese, so you will either need to know Japanese, or have access to a Japanese-to-English translator, to read it.