Small though the display is, its 1024 x 600 pixel resolution is the same as that of millions of netbooks with their larger screens. The resolution of most standard rugged tablets is either 800 x 600 pixel (SVGA) or 1024 x 768 pixel (XGA), so in terms of pixels, the U1 can display as much as the larger tablets. Thanks to its very high pixel density (210 pixels/inch, far more than the original iPhone), the display is very crisp and sharp.

Unfortunately, Windows wasn't designed for such small screens, and so fonts, scroll bars and click boxes can be tiny. A bit of messing around with Windows 7 Control Panel settings (Personalize>Windows Color and Appearance) is needed to get the scroll bars wide enough to be usable. I also moved the task bar to the side so as not to use up precious vertical real estate and set the font size to 125%. Even so, users will quickly learn to appreciate the U1's zoom rocker that lets you zoom in and out almost as effortlessly as on an iPad or Android tablet. You can even pan things around with your finger. Fonts get blocky when zoomed in, though.

The U1 Ultra actually has a different display from the original U1. Specs describe the old screen as daylight-readable and we had it listed as having a maximum backlight brightness of 550 nits. Panasonic describes the new U1 Ultra display as "TransflectivePlus sunlight-viewable." Since transflective is an older display technology that (not very successfully) attempted to merge the advantages of reflective and transmissive displays, the "Plus" apparently refers to the usual optical anti-glare, anti-reflective and circular polarizer treatments, but Panasonic also counts on the reflective part of the display to significantly boost perceived contrast. I was also under the impression that the new display had a 600 nit LED backlight, but the official specs list it as just 380 nit, but with "up to 6000 nit in direct sunlight."

Below you can see what the U1 display looks like outdoors compared to an iPad. The picture was taken on a overcast day which didn't really showcase off the U1's considerable sunlight-viewing capabilities. You can see, however, that the U1 display controls reflections much better than the iPad, and that is important.

One problem with the display is that it has fairly narrow vertical and horizontal viewing angles. The best tablet displays these days have perfect 180 degree viewing angles, i.e. you can look at them from any angle and they remain perfectly viewable. The U1 display has annoying color shifts when you rotate it vertically, and turns milky when you vary the angle horizontally. That's really should no longer be an issue in 2011.

In time that changed and a good number of Atom Z5xx tablets and various industrial/vertical market systems were released. Panasonic used the 1.3GHz Z520 chip in the original U1, and is using the 1.6GHz Z530 in the U1 Ultra. The Z530 is by far the most popular of the Silverthorne family that by now includes a range of processors from the hyper-miserly 600MHz Z500 to the current high-end chip, the 2.13GHz Z560.

As of this writing (March 2011), the Atom Z530 used in the Panasonic H1 Ultra is mid-range in the Atom Z5xx series. It has 512KB of L2 cache, a 533MHz front side bus and a maximum thermal design power of just 2 watts (thermal design power is the maximum amount of power a computer's cooling system needs to dissipate and is used as a measure of power efficiency). That is only a small fraction of what even a frugal notebook processor uses.

The Z530 chip has a tiny 13 x 14 mm package footprint and, small though it is, the processor has about 47 million transistors, which is more than the Pentium 4 had. It is used in conjunction with the very power-efficient "Poulsbo" System Controller Hub (SCH) that includes a GMA graphics system, high definition audio, a PATA controller, and PCIe, SD and USB support, and uses only about 2.3 watts, which means total CPU and chipset consumption is barely more than 4 watts. And the chipset even has hardware support for H.264, MPEG4 and other HD decoding.

We installed Passmark Software's PerformanceTest 6.1 on the Toughbook U1 to measure performance. Passmark's benchmark suite runs about 30 tests covering CPU, 2D graphics, 3D graphics, memory, and disk and then computes scores for each category and an overall PassMark score. We also installed CrystalMark 2004r3, our other standard benchmark suite that measures the performance of subsystems in more detail.

For comparison, we're listing the benchmark numbers of comparable tablet and UMPC devices. The results were as follows:

PERFORMANCE COMPARISON	Panasonic	Black Diamond	DLI	Fujitsu	GD-Itronix	Logic Instruments	Trimble
Model	U1 Ultra	SwitchBack	DLI 8800	UH900	MR-1	FieldBook	Yuma
Processor type	Atom	Celeron	Atom	Atom	Core Solo	Atom	Atom
Processor model	Z530	M	Z530	Z530	U1400	Z530	Z530
CPU Speed	1.6GHz	1.0GHz	1.6GH	1.6GH	1.2GHz	1.6GH	1.6GH
Thermal Design Power (TDP)	2.3 watts	5.0 watts	2.3 watts	2.3 watts	5.5 watts	2.3 watts	2.3 watts
CPU Mark	210.5	236.3	240.4	209.5	328.0	235.5	228.5
2D Graphics Mark	54.4	142.4	127.4	51.4	180.6	84.6	60.5
Memory Mark	190.3	179.7	116.5	181.5	231.7	224.4	200.3
Disk Mark	243.5	163.8	253.9	462.0	183.2	266.4	154.6
3D Graphics Mark	30.0	64.7	16.6	31.3	88.3	9.8	30.5
Overall PassMark	151.0	154.6	176.3	192.6	202.8	170.3	140.8
ALU	5398	3619	5485	5250	4688	5339	5323
FPU	3924	4427	4493	3560	5527	4330	3993
MEM	3942	2665	4077	3879	4734	3706	3987
HDD	8846	3401	4510	11455	3501	5197	5825
GDI	1535	2771	2092	1282	4327	2752	1392
D2D	862	2850	347	265	1231	344	329
OGL	299	861	347	265	1231	344	329
Overall CrystalMark	24806	20594	22019	26506	26936	22721	21834

The results are not terribly conclusive and primarily show that, by and large, the U1 Ultra performs as it should for a Z530-powered machine. And also that Atom-based machines now operate at about the level of older Intel Core and M processors, but at much higher efficiency.

The answer is "a lot." The combination of the supremely power-efficient Atom processor, low power chipset and large-capacity batteries makes for a rated battery life of around nine hours in Panasonic literature. We used Passmark Software's BatteryMon to measure the U1's power draw and found idle discharge rates as low as 4.3 watts, with the power option on power saver and the display on low-bright. And that's with all radios on. With all radios off, power draw often dipped into the high 3-watt range.

For a more realistic scenario we used the Windows 7 maximum power mode, turned all radios on, and set the display brightness to default (which is quite bright). That way, BatteryMon registered a draw of about 8 watts, still good enough for about five hours of operation.

Real life mileage, of course, varies. Between the Atom processor's advanced power conservation modes and the very good power management options in Windows 7, settings can be tweaked to provide performance when needed, then quickly put the system in standby until it's needed again.

In order to keep batteries in top shape and reliable, Panasonic included a Battery Recalibration function that can be used to recalibrate batteries and make sure that remaining battery capacity is displayed accurately. To do that, the utility does a full charge and then a full discharge.

• PC Status, with first logon date and time, elapsed time since current logon, temperature minimum and maximum, registered programs, running processes, and so on.
• Battery Status, including full and remaining capacity of both main batteries, current voltage, discharge rate, battery temperature, etc. Here you can also see which battery the system currently uses.
• Power option, shows the currently selected option and all the settings it uses. This is for lookup only; you set the power savings option elsewhere.
• Setup, with all relevant technical system data
• SMBIOS Data, comprehensive listing of system management BIOS data, including processor, cache and memory information.
• Setup, shows settings, versions and status of various components and options.
• Hard Disk Status, showing file system, free space, and low level disk data

Integrated camera

The U1's camera can take pictures in six resolutions, ranging from 320 x 240 all the way up to 1600 x 1200 pixels. It also has a digital zoom that goes up to 3X magnification in six steps. There is an LED light that, while not replacing a flash, can help illuminate subjects, and make taking pictures in dark spots possible. Menus provide considerable control over all the usual variables (brightness, contrast, saturation, sharpness, color, etc. The camera can also shoot video in what appears 640 x 480 resolution and saved in .AVI format. Recording is serviceable, but at times jumps.

The Toughbook U1 can be ordered with either an integrated 1D laser scanner or an integrated 2D imager. The scanner window is on top of the unit, and there are two dedicated scanner trigger buttons on the back of the unit. The laser scanner employs a 655 nm visible light laser and can decode UPC/EAN/JAN, Code39, Code93, Code128, I2 of 5, D2 of 5, Codabar, MSI/Plessey, Code 11, RSS, Chinese 2 of 5, and their variations.

The 2D imager uses a 655 nm visible light LED and can decode Australian Post, Aztec, BPO, CanadaPost, Codabar, Codablock, Code11, Code39, Code93, Code128, EAN128, DataMatrix, DutchPost, EAN.UCC.Composite, I2 of 5, JapanPost, Matrix 2 of 5, Maxicode, MSI, PDF417, MicroPDF417, Planet, Plessey, Postnet, QR Code, RSS, Stan- dard 2 of 5, Telepen, TLC39, UPC/EAN, and all of their variations.

The Hardware Button Settings Utility can also be used to set the number of lines that are scrolled each time you press the up/down rocker. This can make a big difference in perceived responsiveness, and is just one more example of how endlessly configurable Windows devices such as the U1 are, IF you spend the time finding and configuring everything. It's worth the time as the difference between an optimally configured/customized device and one that uses defaults can be tremendous.

Note that the current Toughbook U1 models are tougher than they already were when they were introduced back in 2008. The ability to survive four-foot drops has now been boosted to surviving six-foot drops. And sealing was increased from IP54 to IP65. What does that mean?

What has come to be known as the "drop spec" is important because mobile computers are likely to be dropped, and one that's being operated in a standing position will likely fall about four feet. Hence, MIL-STD-810G, Method 516.6, Procedure IV describes a testing procedure for a four foot drop. Panasonic managed to increase that to an amazing six feet. More amazingly yet, the test, which mandates 26 drops in total onto 2-inch plywood, was conducted on the same unit that already had been dropped 26 times to four feet and 26 times to five feet. And the device was in "on" position during all those drops.

In terms of sealing, the "6" in the IP65 rating means the unit is totally protected against dust, and the "5" means it is also protected against low pressure water jets from all directions. However, that doesn't make it totally waterproof as a "5" rating still permits "limited ingress." For protection against immersion you'd need IP67, but IP65 is definitely good enough for almost all field deployments.

I've personally seen Panasonic's ruggedness testing facilities in their Kobe factory in Japan and it's second to none. The facility is fully qualified to conduct ruggedness testing according to any standard, and that's in addition to testing performed for them by independent third party testing labs. For a list of all the MIL-STD-810G tests performed, check here. Panasonic also tests for electromagnetic interference (EMI) and electromagnetic compatibility (EMC) in their own R&D facility, and then has those tests certified by third parties. For a list of those tests, check here.

I don't think ruggedness will ever be much of an issue with the Toughbook U1. It is rugged and durable and nearly indestructible. It looks it, feels it, and Panasonic simply has too much experience with making rugged computers to cut any corners.

One somewhat baffling contradiction is the vast discrepancy between the operating temperature range certified in the ruggedness specs (-20 to 140 degrees Fahrenheit) and the range listed in the Operating Instructions manual (41 to 95 degrees Fahrenheit), especially since the latter is further qualified with a cautionary "even within the above temperature/humidity ranges, using for a long time in an extreme environment will result in the product deterioration and will shorten the product life."

Worse, the manual also states that "The computer is designed to minimize shock to parts such as the LCD and the flash memory and equipped with a drip-proof keyboard, but no warranty is provided against any trouble caused by shock."

Based on a very frugal 1.6GHz Intel Atom Z530 processor, the U1 Ultra fields a purposeful, ergonomic, fanless design that's easy to use, easy to hold, and easy to carry. A weight of just 2.5 pounds as tested, and hot-swappable dual batteries that combine for up to nine hours of uninterrupted operation add to the real-life usefulness of the design.

The U1 Ultra is not only compact and light, it also features integrated data capture technologies such as 1D or 2D barcode readers and a documentation camera, and multiple wireless connectivity options, including GPS and the Gobi2000 mobile broadband technology that supports the various wireless networking technologies around the world, so users can select whatever carrier is available to them.

Equipped with a bright, sunlight-viewable 5.6-inch display with a resistive digitizer, the heavily ruggedized Toughbook U1 Ultra is an attractive solution and productivity tool for mobile workers in a large number of fields where equipment may take drops and spills.

There are, however, a number of caveats. While the small thumbtype keyboard is comprehensive, it requires a good deal of getting used to. And while the display is bright and sharp, it's also very small for a massive desktop operating system like Windows 7, and users rely on tweaking the interface and judicious use of various utilities and helper apps. Performance is adequate, but one often wishes for more, especially in areas where the little Atom processor has a hard time keeping up (camera, video, ink flow, etc.) Some of the included systems work great, such as wireless, scanning, broadband, but for a company that makes the superb Lumix cameras, the U1's camera is marginal. Finally, resistive digitizer technology is now struggling to meet the expectations of a new generation of workers used to the effortless elegance of iPhones, iPads and Android devices. So there are some areas where Panasonic can make the U1 even better.