IEEE Milestone Recognizes a Game-changing Laptop

The Toshiba T1100 paved the way for portable computers

22 January 2014

IEEE recently honored a computer that paved the way for the development of the portable, user-friendly machines we use today. The Toshiba T1100, which hit the market in 1985, was the first battery-operated laptop computer fully compatible with the operating system and architecture of the IBM personal computer—the standard computer used at the time in most offices. This meant the T1100 could run the same software that was widely available for most office desktop computers of the day.

To recognize this breakthrough, IEEE named Toshiba’s laptop an IEEE Milestone in Electrical Engineering and Computing. Administered by the IEEE History Center, the Milestone program recognizes outstanding developments with a ceremony and a plaque.


By the early 1980s, personal computers were gaining popularity. However, these computers were fairly large and heavy, often taking up an entire desk—certainly not easy to transport back and forth between home and office.

In 1984 Toshiba set out to develop a smaller machine that could support the same software and complete the same tasks as a desktop computer. Size and power consumption were key issues, so Toshiba engineers had to design compact parts. They used the then relatively new gate arrays, which held large numbers of partly finished logic gates, and designed them to handle functions usually supported by a large number of ICs on desktop computers. For example, the T1100’s display circuit used just five ICs, while IBM’s had nearly 100. This made the laptop relatively compact and light—weighing just 4.6 kilograms—and it consumed less power.

The T1100 was released in Europe in April 1985, and by the end of that year, sales reached 10 000. It hit the market in the United States the following year. The laptop cost less than US $2000 and had no hard disk but a 3.5-inch drive that used floppy disks and a high-contrast, low-power monochrome LCD display measuring 11 cm high and 23 cm wide. It used the Microsoft disk operating system (DOS), which could support some of the most popular business software programs at the time, including Lotus 1-2-3, Reflex, Sidekick, and Word-Star. The laptop had internal, rechargeable batteries lasting up to eight hours. It could also be connected to a monitor or printer.


The T1100’s success did not come without challenges. The IBM desktop PC had a 5.25-inch floppy disk drive used to download files as well as upload software. The T1100’s 3.5-inch floppy meant that not many software companies wanted to use an unfamiliar disk for a system that, at the time, had minimal market share. Toshiba executives repeatedly visited major software companies and eventually persuaded many to release their software on the smaller disks.

Soon after the T1100 hit the market, Toshiba did a number of product promotions to show potential customers that its portable PC allowed them to work at places other than the office. While advertisements for other laptops often targeted computer experts and focused on their hardware and software specifications, Toshiba ads declared the T1100 was designed to be used “anywhere, anytime, by anyone.”

A ceremony for the Milestone was held on 29 October in Tokyo, with a plaque to be displayed at the Toshiba Science Museum, in Kawasaki City, Japan, when the new facility opens in February. The plaque reads:

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 also by the business community.

This article was written with assistance from the IEEE History Center, which is funded by donations to the IEEE Foundation.

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