The device unveiled by the Redmond Washington-based software giant on Monday the Surface isn't the first tablet it envisioned. Indeed, the company's engineers have been trying to reshape personal computing for as long as there's been a PC.
The first PCs had keyboards, borrowed from the typewriter. But people quickly started wondering whether pens, which are more comfortable writing tools, wouldn't be a better basis for personal computing.
Several companies worked pen-based computing in the late 1980s, and Microsoft jumped on the trend. By 1991, it released ``Windows for Pen Computing,'' an add-on to Windows 3.1 that let the operating system accept input from an active ``pen'' (really a stylus).
Several devices used Microsoft's software, and are recognizable as the ancestors of today's tablets: They were square, portable slabs with a screen on one side. They weren't designed to respond to finger-touches, however: the reigning paradigm was that of the notepad and pen.
The pen-computing fad subsided in the 90s. While PenWindows tablets got a lot of attention, mainstream computing remained stubbornly keyboard-based.
In 2002, Microsoft founder Bill Gates said these early tablet ventures were ``almost painful to recall,'' but not to worry. He had something much better, a device that would fulfill ``a dream that I and others have had for years and years,'' he said.
It was Windows for XP Tablet PC Edition. This time, hardware makers like Hewlett-Packard Co., Samsung Electronics, Toshiba Corp. and Acer Group played along, producing tablet PCs.
Like the earlier generation, some of these looked like today's tablets, but inside, they were really PCs. Compared to an iPad, they were expensive _ at around $1,500 _ heavy, and didn't last long on battery power. Buyers paid a lot for the ability to enter things on the screen with a pen.
Another problem was that the pen-based adaptations were skin-deep. Windows remained a thoroughly keyboard-and-mouse-based operating system, and many functions were simply hard to get to with a pen. Third-party applications weren't converted for pen use at all. As a backup, many of these tablets had keyboards, just like laptops.