Review: Willcom D4 (Sharp WS016SH)


The Willcom D4 (Sharp WS016SH) UMPC is currently the smallest-screened Centrino Atom device running Windows Vista in the world. Launched alongside the Kohjinsha SC3 on July 11th in Japan, the 40GB slide-and-tilt handheld computer is an unlikely candidate to see an official release outside of Asia, but that doesn’t mean it can’t make it to American soil. With the help of an importer like, anything is possible.

But is the 1-pound UMPC worth the premium import price (about $1500 new, $1200 used)? Read my full review below to find out.

System Specifications

OS: Windows Vista Home Premium
1.33GHz Intel Atom Z520
Intel US15W, GMA500
RAM: 1GB DDR2 SDRAM (soldered onto motherboard)
Storage: 40GB HDD (1.8" Toshiba MK4009GAL, 4200 rpm)
Expansion: MicroSD card slot
Display: 5” touchscreen (1024 x 600, 262K colors, LED-backlit)
Wireless: 802.11b/g, Bluetooth 2.0
(1Seg TV tuner & phone functions work in Japan only)
Camera: 2 megapixels
Size: 7.4" x 3.3" x 1.0"
Weight: 1 lb. (with standard battery)

Take a look at my Willcom D4 unboxing for photos of the packaging and included accessories. An extended battery, docking cradle (review), and other accessories are available separately.



The glossy black D4, perhaps taking a cue from the HTC Shift, features a slide-and-tilt design that encourages versatility in the way it can be used.

  • Held between two hands, the D4 is a slider UMPC to entertain those waiting in line, lounging on the sofa, or commuting to work. Its rounded all-black casing, accented with silver trim and glowing red controls, is eye-catching and undeniably attractive.
  • Set atop a flat surface, screen tilted to best suit the user, the D4 becomes a miniature notebook for sending email at coffee shops and editing documents at work. Its smooth, streamlined body and sturdy build give it a look of sophistication and professionalism.
  • Left in slate form, screen orientation switched to portrait mode, the D4 is a small tablet for taking notes in meetings, reading eBooks, and viewing daily appointments at a glance. Its long yet compact form factor makes it easy to hold and slip into/out of a jacket pocket, briefcase, or bag unnoticed.

The glossy surface, used around the display only, is not resistant to fingerprints and smudges, but it doesn’t collect them too quickly/easily either. Extended use of the unit with oily thumbs will leave behind some arch, loop, and whorl evidence, but it’s nothing a quick wipe with a cloth (or sleeve) can’t get rid of.



View my D4 size comparison post for photos of the Centrino Atom slider alongside a handful of other UMPCs, a few other gadgets, and some common household items.


The Willcom D4 has a 5-inch touchscreen with a resolution of 1024 x 600. The energy-efficient LED backlighting means the display can be kept at higher brightness levels with very little effect on battery life (more on this later).


Colors are nicely saturated and accurate; viewing angles are equally good, with that "negative effect" occurring only when looking at the screen from the bottom (unnatural, anyway). Side and top angles are acceptable, but the display obviously looks best when viewed head-on.



As with the HTC Shift and AT&T Tilt, when the D4’s display is slid up and positioned at various angles, a full QWERTY keyboard is exposed. The sliding mechanism isn’t spring loaded, but it glides up smoothly and "locks" into place. The hinges are sturdy and allow the display to stay positioned at all angles equally well.



The D4’s passive touchscreen won’t fulfill an inking enthusiast’s dreams, as the display is small compared to full-size tablet PCs and vectoring can sometimes be an issue, but it’s suitable for jotting down quick notes and some nonsense doodling.


I’m not an inker myself, but if inking is something you want to do on the D4, then do it in portrait mode. A dedicated screen rotation button on the top of the device makes switching orientations instant, even faster than accelerometer-based rotation. The writing area in portrait mode is small enough for your palm not to have to rest on anything and the rectangular notepad-like shape of the device feels natural to hold in one hand.


The Willcom D4’s main controls are located on either side of its display.


When touched, a pattern of dots on the mouse buttons (left) and touch pad (right) light up red. This glowing effect never fails to impress first-time users of the D4, as it makes the unit seem incredibly stylish and even a bit futuristic. Touch-based lights are not new, of course, but few expect to see them on a UMPC.


The mouse buttons are stac
ked on top of each other and correspond to the left and right buttons on a standard computer mouse. They’re very responsive and easy to press. The buttons have a nice spring or bounce to them as well, so tactile feedback is excellent.


As noted in my early impressions piece, the touch pad is a mixed bag for me. It looks great, which is something most people can’t say about a touch pad, and is large enough to make navigation feel very natural. It’s actually one of the largest I’ve ever seen (much bigger than the one on the Shift). The auto scroll areas (tap once to move about one-fifth up/down the page, double-tap and hold to auto scroll) come in handy when browsing the web, and the center of the pad can be tapped to select items.

The biggest drawback is that the glossy finish on the D4 isn’t as well suited for controlling the mouse/cursor as a traditional touch pad. The only time the shiny surface allows thumbs to glide over it effortlessly is when they are free of oil. Even a light amount of natural finger oils makes the touch pad a little difficult to use.

That said, I find the touch pad to be better than the pointers/joysticks found on UMPCs like the OQO Model 02, Fujitsu U810, and Sony UX series. It’s easier to control, more accurate, and more comfortable.


Having the main controls flanking the display allows the D4 to be used in two-handed slate mode with little compromise. Some UMPCs, like the Kohjinsha SC3 for example, keep their navigational controls on their keyboards, which often forces users to interact with the touchscreen (and with Vista, that usually means holding the unit in one hand and using a stylus with the other).

The problem with this layout is that it requires some hand/finger repositioning when using the unit with the keyboard exposed. It feels more natural to hold the D4 by its keyboard when the display is slid up, but doing so puts the touch pad and mouse buttons out of easy reach. It’s give and take, really, as the only way to resolve the issue would be to put a set of controls on both the keyboard and display areas. And that would be overkill.

I tend to use the D4 most often in two-handed slate mode. Whenever I need the keyboard, I just slide it out, reposition my hand to use the touch pad or mouse button (whichever is needed to activate text entry), and then move my hand back to start typing. It sounds unwieldy, but it quickly becomes second nature.

Hardware Tour

The keyboard is discussed in its own section below, so let’s take a quick tour around the device to check out rest of the hardware first. Most of this was shown in my D4 unboxing, so feel free to jump down to the next section if you’ve already seen it.



LED status indicators reside at the top of both sides of the display. Power and battery indicators are on the left; wi-fi, cell signal (Japan only), and hard drive lights are on the right.



At the top of the D4 are a telescoping antenna (for use with the Japan-only 1Seg TV tuner), camera button, screen rotation button, power button, and non-standard headset port. Beneath the antenna is the stylus slot.


Next to the headset port is one of two air vents and a covered power port.


On the left side are covered slots for a W-SIM (Japan only) and microSD card.


Nothing is on the right side of the unit, but a covered dock connector, covered mini USB 2.0 port, and sliding lock/hold switch are on the bottom.


On the back of the display panel are a 2-megapixel digital camera and small mono speaker (in line with the camera at the bottom).


The back of the D4 is covered in a very smooth rubber similar to that of the Raon Digital Everun and is home to the battery compartment, the second air vent, and four rubber feet.




Beneath the Willcom D4’s display panel is a 64-key backlit QWERTY keyboard with a layout that differs only slightly from a US keyboard. Aside from a few punctuation keys and symbols, everything else is where US users will expect them to be.


The keys are well sized and provide a decent amount of feedback, but they are very flat and have very little travel.


This makes laptop-style typing more difficult than on the HTC Shift, Kohjinsha SC3, or Fujitsu U810, which are all equipped with miniaturized versions of "regular" keyboards. Hunt-and-peck typing is not impossible, but it’s not as comfortable as the aforementioned devices because the keys require a deliberate press, which is something that most fingers aren’t accustomed to doing. Because a light tap isn’t enough for the keystrokes to register (and my "y" key is less responsive than the other keys for some reason), my laptop-mode typing speed (45 wpm) is only marginally better than my thumb typing speed (43 wpm). You can compare these speeds with my other mobile device keyboard results here.


Though the D4 is too long for comfortable thumb typing, the keyboard is actually better suited for it. The keys feel better under the thumbs and are easier to press with more accuracy. Even though my thumb-typing speed is slower than my hunt-and-peck typing speed, I find myself thumb typing much more often (the D4 is more of a two-handed device for me, anyway). I can’t do it for very long before my right thumb gets sore (because of the layout, my right thumb stretches more than my left), but it’s fine for short bursts of text. I even wrote this post with my thumbs!

The D4 keyboard may not be what many hoped it would be, but I’m reasonably pleased with it.


The Willcom D4 sits on the same Centrino Atom platform as the Kohjinsha SC3. Both run Windows Home Premium on a 1.33GHz Intel Atom Z520 CPU (SCH US15W "Poulsbo" chipset), the D4 on just 1GB of RAM and my upgraded SC3 on 2GB. Performance, then, is quite similar. The D4 stays pretty cool while in use, but the fan lets out an audible whirring to make that possible. The sound is very noticeable in a dead-silent room but can’t really be heard in any other environment.

You may have already seen my 14-minute video overview of Vista on the D4, which shows the UMPC engaged in numerous tasks, but here it is again:

As before, the video shows the D4:

  • Awakening from sleep
  • Loading system icons and switching windows with Aero enabled
  • Launching Firefox 3
  • Viewing quick snippets of YouTube and Hulu video
  • Opening 10 tabs in Firefox while streaming internet radio in one of them
  • Running Firefox 3, Open Office, Adobe Reader, and iTunes simultaneously

Performance is largely subjective, as everyone’s current systems and personal needs are different, but I don’t think the D4 has anything to be ashamed of. Considering that it has just 1GB of RAM, I think it handles Vista quite well. I never understood what the "Vista doesn’t belong on UMPCs" outcries were about, anyway. I still don’t.

The new Poulsbo chipset, meanwhile, is still struggling to find its way to bring video acceleration and smooth HD video playback to the masses. 1080p H.264 has officially been saved by CyberLink PowerDVD (see video for more), but other codecs are still waiting to be rescued.


Here’s something less subjective for you benchmark fanatics to take a look at.





I don’t put much stock in benchmark results, as it’s more meaningful for me to know that a system awakens in under 5 seconds than that its Fibonacci score is 1522. But to each his own.

Battery Life

If you’ve been relatively impressed by the Willcom D4 so far, then here’s where it gets ugly. Very ugly. As most of you know from my standard battery (CE-BL57) wi-fi runtime post, battery life is abysmal. Sharp/Willcom have always been upfront about the standard battery’s "up to 1.5 hours" operating time, but that doesn’t excuse it. That the D4 can also be used a phone in Japan makes the battery life even more pathetic.

Even worse than the drain rate is how quickly the battery’s capacity seems to deteriorate. About 2.5 weeks ago, I was getting a little over an hour of wi-fi time (as shown here). Today, the 960mAh li-ion battery is unable to break the one-hour mark under any condition:

  • Screen off, wi-fi/BT off, music on microSD with iTunes: 53 minutes
  • Mid brightness, BT off, web browsing with FF3 over wi-fi: 43 minutes
  • Mid brightness, wi-fi off, web browsing with FF3 over BT tether: 46 minutes
  • Mid brightness, BT off, online video playback with FF3 over wi-fi: 34 minutes
  • Mid brightness, wi-fi/BT off, word processing in OpenOffice: 54 minutes
  • Max brightness, wi-fi/BT on, web browsing with FF3 over wi-fi: 40 minutes

The standard battery receives a full charge in about 1.5 hours.

Extended Battery (CE-BL58)


If you’re considering the Willcom D4 as your next UMPC, then you have to get the 2880mAh extended battery (CE-BL58) too. I got mine free during the launch promotion, but sells it as an option when you purchase the unit.

I received the new battery yesterday, so I’ve only been able to run one test:

  • Mid brightness, BT off, web browsing with FF3 over wi-fi: 2 hours, 50 minutes

Although not exactly in line with Sharp/Willcom’s "up to 4.5 hours" estimate, compared to the measly 43 minutes the standard battery provides under the same conditions, the extended battery does seem to make good on its promise of more than tripling average runtime.

The extended battery receives a full charge in about 4.5 hours.



A replacement backing is included with the extended battery. And as you can see, it’s considerably bigger than the standard one.




The battery adds 0.4 inches of thickness and about 0.25 pounds to the D4, but the extra runtime is well worth the bulk.



In addition, the extra chunkiness actually makes thumb typing more comfortable (hunt-and-peck typing isn’t affected). Typing speed is still about the same, but the added thickness lets me reposition my hands more naturally to reach all the keys. The thicker unit and tapered backside also make the device easier to hold.

The extended battery also still allows the D4 to use most of its accessories. The bundled pouch is a tight fit, but the docking cradle (available separately) was actually designed with the extended battery in mind.


In other words, there aren’t any major trade-offs associated with the high-capacity battery. It makes the device thicker and heavier, sure, but it also becomes more comfortable to hold and improves the thumb-typing experience. And even at 1.25 pounds and 1.4-inches thick, the D4 is still very portable.


So that’s the Willcom D4 (Sharp WS016SH) Centrino Atom UMPC in a very big, longwinded nutshell.


Out of the box, the D4 will frustrate users with its awful battery life, poor video performance, non-standard headphone jack, and lack of USB 2.0 host port. With the extended battery and a few other add-ons, it is capable of pleasing a diverse set of users with its high-resolution LED-backlit touchscreen, gorgeous design, versatile form factor, backlit keyboard, respectable battery life, and fairly impressive Vista performance.

Basically, then, the D4 needs help to achieve its potential. Some users may begrudge the idea of having to make the device work as it should on their own, but I don’t mind. That’s probably why the compact device has already become one of my favorite UMPCs (the HTC Shift is still #1; I guess I’m a big fan of the slide-and-tilt design). Not only do I use it all the time, but I want to use it all the time. I honestly can’t look at it without wanting to pick it up.

I can understand why the Willcom D4 may not be the right UMPC for you, but it’s definitely one of the right ones for me.

The Willcom D4 is not officially available outside of Japan, so you’ll need an importer to get your hands on one. Fortunately, the friendly folks at are standing by with used D4s (they don’t sell new units) for about $1200. New units can be purchased from other importers for about $1500.

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Jenn K. Lee

Jenn K. Lee is the founder of Pocketables. She loves gadgets the way most women love shoes and purses. The pieces in her tech wardrobe that go with everything are currently the Samsung Galaxy Note II, Sony Tablet P, and Nexus 7, but there are still a couple of vintage UMPCs/MIDs in the back of her closet.

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