The HP Compaq TC1100 is only 10 years old, but in mobile computing years, it’s laughably archaic.

Running Windows XP Tablet PC Edition, this device practically dared its owners to enter text without assistance from a bundled snap-on keyboard. It was frustrating then, and it's a museum piece now. Yet the TC1100 was perhaps the best hardware expression of Microsoft’s original tablet effort, and it still tells an instructive story about the origins of Surface Pro 3.

Image: Michael Homnick It may have been a tablet, but the TC1100 still sported a wide, silvery bezel like so many notebook chassis of its day.

The TC1100's design DNA can be found throughout Microsoft’s latest, greatest, 4-star tablet. Both machines were expressly designed as 2-in-1, laptop-tablet hybrids. Both come with styluses. And both feature fully functioning Windows desktops.

The TC1100 isn’t easy to use by any means, but it shows Microsoft had the right idea.

Hot to the touch, heavy in the hands

The TC1100 you see in this article had been sitting in my box of discarded tech toys since 2004. I first wrote about the tablet in May of that year, and generally liked HP’s effort. But it didn’t take long for the tablet’s considerable avoirdupois to break my spirit. Even worse, I never warmed to Microsoft’s primitive handwriting recognition.

I eventually lost the TC1100’s bundled keyboard, which turns the device into a full-blown laptop. But when Surface Pro 3 came out, I was excited to discover that the HP tablet still booted, and more or less worked—the utter vulnerability of Windows XP notwithstanding.

Image: Michael Homnick At 0.36-inch thick, the Surface Pro 3 is less than half the thickness of the 0.8-inch thick TC1100.

In a side-by-side comparison with Microsoft’s flagship tablet, the first thing you’ll notice about the TC1100 is its weight. At 3.1 pounds, it weighs almost twice as much as the 1.76-pound Surface Pro 3. And let’s not forget that the first-generation iPad, released in 2010, weighs only 1.5 pounds. HP’s device is a brick compared to either machine, and its 1GHz Pentium M processor also runs quite hot. The end result is a tablet that scorches your lap, and begins to feel like a kettlebell if you hold it in your hands for too long.

No wonder these original Windows tablets didn’t sell: People didn’t want to use them.

Blurry, blurry pixels

Tablets like the TC1100—or even the original iPad—should make us eternally grateful for modern pixel pitches. The HP tablet features a 10.4-inch display saddled with a 1024x768 screen resolution that looks primordial by modern standards. The machine’s pixel pitch is a blurry 123 pixels per inch, and, trust me, the fuzziness of these old displays is worse than you even remember.

At 12 diagonal inches, the Surface Pro 3 display isn’t much larger in terms of pure dimensions. But Microsoft’s latest hardware boasts a 2160x1440 resolution, delivering the stunning sharpness of 216 pixels per inch.

Image: Michael Homnick Macro photos show just how far pixel density has come since 2004. We see Surface Pro 3 on the left, and the TC1100 on the right.

Poor image clarity aside, the TC1100 foisted an even worse indignity upon users: a resistive touchscreen.

The HP tablet doesn’t respond to any of the swipes, finger jabs, or touch gestures that bring life to modern capacitive touchscreens. In 2004, the best the PC industry could muster was stylus-driven touch that depended on direct pressure applied to the screen. The first iPhone gave us capacitive touch as a standard in 2007, and modern mobile interfaces exploded from there. We began finger-gesturing through apps instead of mousing through applications, and an entire new computing experience was born.

Choose your text-entry poison

When the TC1100 is docked in its keyboard accessory, it’s all but indistinguishable from any other laptop circa 2004. The Pentium M is paired with a paltry 512MB of RAM and a 40GB mechanical hard drive. Running the stylus-oriented tablet edition of Windows XP, that aging boot drive yields start-up times exceeding 15 seconds—an anachronism in today’s era of solid-state storage and instant-on tablets. In fact, even the Surface Pro 3 boots from completely off to its Windows 8 password screen in about four seconds.

Image: Michael Homnick The two devices’ respective pens really aren’t that different in size. But after 10 years, the rubbery grip on HP’s black stylus disintegrated, so I replaced it with a strip of Scotch tape.

But the biggest problem with the TC1100 emerges when you ditch the keyboard attachment, and use the machine like a straight-up tablet. There’s just no easy, convenient way to get text into the machine. And, remember, this device doesn’t run mobile apps a la iOS, Android, or Microsoft own “modern” apps. It runs traditional Windows desktop applications, many of which are geared toward long-form text entry.

Your first text-entry option involves using the TC1100’s stylus to tap-type on Microsoft’s awkward virtual keyboard (see the video at the top of this article). It borrows the layout of a traditional notebook keyboard in all the worst ways, and for some inexplicable reason, Microsoft labeled each key with a tiny, faint, barely legible key character. Using a stylus to hunt-and-peck letters into a Word document is not a rewarding experience.

Character recognition... at its wonkiest

Your second option is to use the virtual keyboard’s Character Pad tool. With this method, you deliberately draw out letter forms on a thin strip of virtual note paper, making sure each character stays within its own boundary box. The character recognition is much more miss than hit. My lowercase “s” too often gets recorded as a “5.” My uppercase “C” is interpreted as an open parenthesis. And so on. Use the Character Pad, and you’ll begin hating the English language itself.

Image: Michael Homnick You won’t find a port cupboard like this in a modern tablet.

The Writing Pad tool is your third option. With this method, you use digital ink to scratch out entire sentences in long form. Once you think you’ve got a cogent collection of words, you hit the Insert button, and Windows XP Tablet PC Edition will convert your penmanship into word-processed letters with varying degrees of success. Sometimes Microsoft’s character recognition will amaze you. Other times, it performs just as badly as what you’d expect from 10-year-old technology.

But, hey, this is why we love what iOS did for mobility in 2007. Virtual keyboards that enable capacitive-touch finger typing are revolutionary for a reason: Because stylus-driven text-entry is a complete pain in the ass.

A common Windows DNA

Without a doubt, Apple hardware gave life to the modern mobile revolution. The first iPhone gave us capacitive touch and easy finger typing, and the first iPad gave us instant-on tablet computing in a package that we could defensibly call thin and light.

But we’d all be bad historians if we didn’t recognize Microsoft’s honorable (if failed) efforts to make tablet computing work five years before Apple gave it a go. And when you compare the TC1100 to the Surface Pro 3, you have to admire the consistency of Microsoft’s vision.

Image: Michael Homnick One old, one new. One failed, one successful. Two entirely different machines, but born of a single vision.

It took the company 10 years, but Microsoft finally has the 2-in-1 productivity machine it always dreamed of. The Surface Pro 3 comes with two effective keyboards (one virtual, one hardware); a pen that delivers the best that digital ink has to offer; and a desktop that runs all the applications in the Windows universe.

It sounds a lot like the TC1100. But the 2014 version actually works. This is what you get when hardware tech finally catches up to a solid, if over-ambitious design brief.