Milestones:Toshiba T1100, a Pioneering Contribution to the Development of Laptop PC, 1985


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Toshiba T1100, a Pioneering Contribution to the Development of Laptop PC, 1985

The Toshiba T1100, an IBM PC compatible laptop computer that shipped in 1985, made an invaluable contribution to the development of the laptop PC and portable personal computers. With the T1100, Toshiba demonstrated and promoted the emergence and importance of true portability for PCs running packaged software, with the result that T1100 won acceptance not only among PC experts but by the business community.

The plaque may be viewed at the entrance hall of Tachikawa office of Toshiba Client Solutions Co., Ltd., Tachihi Building 2, 6-1-3 Sakae-cho, Tachikawa-shi, Tokyo 190-0003, Japan. The Toshiba T-1100 was developed in Ome Complex of Toshiba Corporation in 1984-1985 and mass production also was performed by this factory. The factory had closed down in 2017 and the plaque moved from the factory to Tachikawa office of Toshiba Client Solutions Co., Ltd.

Historic significance of this work:

Today, people can carry and use portable PCs wherever they go, and access and use the same environment as at home or in the office. However, in the mid 1980s, although personal computing won increasingly wide acceptance with the Apple II in 1977 and the IBM PC1 in 1981, it was still limited to a fixed desktop environment.

The 1980s saw the emergence of portable computers. As the IBM PC penetrated the world market and established a de facto standard for desktop PCs, some companies developed smaller computers. Among them were Compaq’s 1982 “Portable I”, a suitcase-sized computer that weighed 12.5kg.; Seiko’s 1982 “HX-20/HC-20”[2], which weighed 1.6kg.; and NEC’s 1983 “PC8201A”, which weighed in at about 1.7 kg. There were two approaches to portable computers. One focused on size and on small, easily carried PCs. They were designed with dedicated architecture and their software and data formats were incompatible with those of other PCs; people could not use them for data brought from the office, or had to convert that data to match the smaller computers. The other approach was to try to build portable IBM PC compatible machines, designed for the same environment as the IBM PC in the office. However, because of technical difficulties, such as lack of suitable display or the need to develop a chip set to fit a portable machine, these pioneering machines were all crippled in some way and could not support full compatibility with the IBM PC.

In April 1985, T1100 was released as a laptop personal computer that was fully compatible with the IBM PC. The design target of T1100 was “anywhere, anytime, anyone”

In the early 1980s, prior to the IBM PC, personal computers were, like mainframe computers, mainly tools for computer experts. Using computers required special knowledge of system architecture, programming and the like. The IBM PC had started to change this situation in the office, but personal computers were still big, expensive things that had to be set up on a dedicated desk. Back then, most people had to move to the PC desk when they wanted to use the PC. In other words, the office of the ’80s was a PC-centric environment to which people had to adapt themselves. The T1100 was designed to break these chains.

The T1100 was fully IBM PC compatible. That meant that users had access to widely available software at their desk, with no need to write programs themselves or to buy different software for dedicated portable computer architecture. But in developing the T1100, Toshiba met a big problem.

The original IBM desktop PC had a 5.25 inch floppy disk drive as default. All software for IBM PCs was shipped on 5.25 inch floppy disks. But Toshiba wanted to install a 3.5 inch floppy disk drive on T1100, to support its portability. At that time, the 3.5 inch floppy disk was a brand new product, and no software venders wanted to ship their products on an unfamiliar disk for a system that had minimal market share. Toshiba thought that releasing software on 3.5 inch floppy disk was essential as a means to expand business to users who could not write their own programs. People from Toshiba made repeated visits to software venders and finally won their agreement to release software on 3.5 inch floppy disks.

Beyond this, Toshiba did product promotions to show potential users that a portable PC allowed them to continue to work even when away from the office. All they needed was a T1100 and the package software they used in the office. Promotions by other makers targeted experts and focused on the advantages offered by their hardware and software specifications. Toshiba’s different and more appealing promotions opened the eyes of business users who were not PC experts and really expanded the portable PC market.

After shipping of T1100, Toshiba researched market opinions on the T1100. Some people admired its portability but others wanted a faster PC and more storage. Toshiba responded in January 1986 with the release of two more laptops in addition to the battery-powered T1100: the T2100 and T3100. The T2100 had an i8086 CPU, two 3.5-inch floppy drives and a plasma display. The T3100 had an i80286 CPU and 10 megabyte hard disk drive along with the 3.5-inch floppy disk drive. Both required AC power, but PC Week magazine saw this as no problem as it recognized that there was an AC- powered portable PC market. Byte Magazine called the T3100 the “King of Laptops”. With this line-up, Toshiba won about a 40% share of the 130K portable PC shipped in Europe in 1987 (source: Dataquest European Personal Computer Industry Service, July 1988).

The emergence and growth of the portable PC market also established a significant parts market for portable PCs: by 2008, the market for LCD displays smaller than 17 inches was $15B, for HDD 2.5-inches and smaller $19B, and for lithium-ion batteries for mobile equipment $12B. (sources: Fuji-Chimera Research Institute, Inc. for displays and HDD; CMC Publishing Co., Ltd. for batteries).

In 2009, sales of portable PCs exceeded those of desktops, and the market had a value of $150B. .

 T1100 was designed for use “anywhere, anytime, anyone”. In its in-house discussions, Toshiba defined its concept as “revolution on the desk top”. The implication of this was a shift, “from PC-centric usage to user-centric usage” and a computer that “anyone, including non experts, can buy (cheap) and use (easy)”. Sub-targets were: (1) from dedicated architecture to standard architecture; (2) from the desktop to a laptop/notebook; and (3) no need for users to write software themselves, just use it. From this perspective, the T1100 was not just a smaller version of an IBM PC but pioneer in opening the door to computers for business users.

Promotion materials for most PCs from around 1985 feature the hardware and software specifics and show some examples of use. But the T1100 proposed a new way to use portable PCs. At a desk, the T1100 could be connected to external color display and run same software as the IBM PC. Then, when users moved to another place, they could disconnect the T1100 from the display and bring the T1100 with them wit the software on a floppy disk. This allowed them to continue their work wherever they went. To support this usage, T1100 had a built-in RGB connecter. However, at that time it did not have telephone modem. Back then, the reason for having am modem was to access a mainframe, something most business users never did.

To support portability, the size of the machine and power consumption were key issues. Toshiba engineers developed compact parts. Gate arrays was designed to handle functions that were supported by a large number of ICs on desktop IBM PCs. Toshiba selected CMOS technology for the gate arrays, even though most ICs then were designed with NMOS technology. For example, the T1100’s display circuit had only five ICs, while a desktop IBM PC had nearly 100. With this solution, the T1100 was not only compact and light, weighing only 4kg, it also had lower power consumption. In another hardware solution, Toshiba developed a charge/discharge mechanism and power control software, then not available for IBM PC machines, that secured an extended battery life. This power control technology would enable later Toshiba portable PCs to add a resume function (J3100SS001 in 1989), and in an improved for it provided the basis for the current “ACPI (Advanced Configuration and Power Interface)” defined by Toshiba, Microsoft and Intel.

Toshiba also developed a higher contrast LCD panel for the T1100, introducing it as an adjustable tilting display for crystal-clear, high contrast viewing. This was a result of extensive testing to determine display viewing angles and LCD contrast. 


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