However, classifying the MC55A0's exact role in Moto's EDA roster is a bit tricky. The problem is that Symbol recognized early on that industrial handhelds are not one-size/technology-fit-all and tried to offer variants to fit all needs and preferences. This resulted in models that came both in versions with and without keyboards (see the original MC50), or models that had snap-on keyboards. Likewise, some applications require cellphone functionality and wireless wide area network (WWAN) radios. That is why the MC55 came in two versions, the "inside the four walls" 5590 model and the "outdoor" 5574 model that included GSM/GPRS/EDGE voice/data communication capabilities. The "outdoor" 5574 also had a 44-key full QWERTY thumb-type keyboard whereas the "indoor" 5590 made do with a 26-key phone-style keypad.

Apparently, Motorola decided that WWAN and non-WWAN models are sufficiently different to dedicate a model line to each, and so the original MC55 line has now split into the MC65 (introduced in March of 2010 as a tougher, faster WWLAN version of the MC5574; see here), and now the MC55A0, representing a faster, tougher version of the earlier "inside the four walls" non-WWAN MC5590. Both combine the functionality of a bar code scanner, a camera, a walkie talkie and a mobile computer into one small and handy device, but the new MC55A0 does so without also having WWAN functionality (and the accompanying antenna nub).

What the MC55A0 does represent is a significant technology update to Motorola's midrange EDA, one that brings all components up to the current technological state-of-the-art, and also adds a degree of additional ruggedness. Below you can see how the MC55A0 fits into Moto's EDA lineup with the small and recently introduced ES400, the updated MC55 discussed here, and the top-of-the-line MC75A:

Above: Motorola's Enterprise Digital Assistants ES400, MC55A0, and MC75A

In terms of looks and design, the MC55A0 is almost indistinguishable from the MC55 it replaces, but looks deceive as the MC55A0 is faster, tougher, better sealed and has more features. And that's on top of the usual tech updates common in this fast-paced world of handheld electronics.

So let's take a look at what all the new MC55A0 offers:

The first thing those already familiar with the MC55 will notice is a switch from QVGA (240 x 320 pixels) to full 480 x 640 pixel VGA resolution. That means four times as many pixels and a much sharper display, one suitable for today's more complex applications and web pages. That's only part of the display news, though. Moto also installed a new display technology called "PenTile." This has nothing to do with "pen." Instead, the name implies a tile subdivided into five (penta) areas, though the matrix scheme used by Moto seems to use four, the fourth one being white in addition to the usual RGB (red - green - blue). The addition of a white sub-pixel increases perceived brightness and contrast, and the display uses significantly less power (see Wiki entry on PenTile technology). Moto initially used a PenTile display in the ES400. Backlight strength is given as 650+ nits; very strong indeed for a device designed primarily for use inside those four walls.

The other big thing users will notice is much quicker performance thanks to a switch from the 520MHz Marvell PXA270, a processor that reliably powered generations of Pocket PCs, to the 806MHz Marvell PXA320, which, while also no longer new, represents the speedy, versatile and power-efficient top of that processor line. It's interesting that for the MC55A0 Motorola upgraded within the Marvell lineup while they switched to a 600MHz MSM Qualcomm 7627 CPU for the MC65 (the chip that's used in the Palm Pixi, a variety of other smartphones, and, most notably, in Moto's own recently released ES400). Perhaps that has something to do with the Qualcomm chip's suitability for WWAN applications.

The OS is another area where the new MC55A0 parts ways with the MC65. The MC65 runs Windows Mobile 6.5 Professional with a customizable user interface courtesy of MEUI, Motorola's Enteprise User Interface that's supposed to provide quicker and easier access to features and apps and lets users tailor the device to their workflow. The new MC55A0, however, uses standard Windows Mobile 6.5 Classic, which Microsoft may (or may not) now call Windows Embedded Handheld. Whatever it is, it's not clear to me why Moto chose to use two different interfaces, and thus only contributes to the puzzlement and guessing over Microsoft's direction with its beleaguered mobile OS.

Like in the MC65, onboard RAM has doubled to 256MB, and onboard Flash quadrupled to 1GB compared to the MC55, and there's an micro-SD Card slot that supports cards up to 32GB. There's integrated 802.11a/b/g WiFi and Class II Bluetooth as before (BT now is version 2.1), and the MC55A0's integrated camera now sports higher 3.2-megapixel resolution.

In terms of size and weight, the MC55A0 remains unchanged, still measuring 5.8 x 3.0 inches with a thickness of just over an inch. Weight is about 11 ounces with the standard 3.7 Volt/2,400mAh battery. That means that the MC55A0 is quite a bit larger and heavier than iPhone/Droid-style consumer smartphones, but it still fits into most pockets. Without integrated WWLAN, the MC55A0 doesn't have the protruding antenna nub, and that alone makes it a bit handier.

The touchscreen display remains a generous 3.5 inches diagonally and uses a glass analog resistive digitizer. Along with the OS uncertainty, this is another area where the mid-range Moto EDA remains in a holding pattern. Almost all consumer smartphones, including those that use Microsoft Phone 7, now have projected capacitive touch screens, a technology that does not (yet) work with gloves. I am not sure gloves are a compelling argument for staying with a resistive digitizer since a 3.5-inch display and the small icons and operating elements are best used with a stylus anyway. Perhaps we'll soon see combo resistive/projected capacitive panels.

In terms of ruggedness, the original MC55 was far tougher than any commercial market PDA, but the new MC55A0 is tougher yet. It can now handle 6-foot drops instead of four, is sealed to IP64 specifications instead of the MC55's IP54. In IP64 sealing, the "6" means the device is now completely sealed against any dust intrusion (as opposed to allowing small accumulations), and the "5" that it is protected against low pressure water jets from all directions. The operating temperature range is a wide 14 to 122 degrees Fahrenheit. Motorola also quotes a "tumble spec" where the devices survive 1000 1.6 foot tumbles, twice as many as the already tough MC55. Note that the MC55A0's increase in ruggedness splits the difference between the old MC55 and the outdoor-oriented MC65 (which sports IP65 and 2,000 tumbles).

As pretty much all Moto devices, the MC55A0 is well equipped for data capture. Like with the MC55, customers can order units with either the Symbol SE960 1D laser scanner, or with one of three variants of the Symbol SE4500 2D imager (SR for medium to low density 1D and 2D bar codes, DL for medium to high-density bar codes, and HD for very high density codes). Note that this is different from the MC65 that only comes with the imager. Customers can also opt for a 3.2mp auto-focus camera with a user-controllable flash for stills and video. An optional snap-on magnetic card reader is available as well.

As far as keyboards go, Motorola makes no fewer than five layouts available (26 and 44-key in various international layouts) whereas before, the "indoor" model was limited to the lower key count layout.

Note that Motorola also offers the healthcare-oriented MC55A0-HC with a blue-white color scheme that fits well into clinical environments. In all other aspects, the healthcare versions seems identical to the standard MC55A0.

In summary, the MC55A0 is a fairly substantial technology update to the MC55 that was designed to fill the gap between consumer PDAs and industrial devices. As such, the MC55A0 is a cross-over product that's both handy and rugged, serves as an advanced data capture device with even better lasers and imagers, and offers robust voice and data communication. Note, though, that there is no cellular radio/3G, so voice communication is push-to-talk using VoIP and data comm requires proximity to a WiFi hotspot (for cellular voice/data you'd need the slightly tougher but otherwise largely identical MC65).

The MC55A0 is a well-conceived, well-executed update that brings the standard MC55 platform up to current standards. Peripherals are all backward compatible -- an important consideration in the field. About the only concern we have, apart from the uncertainty over Windows Mobile, is the somewhat confusing nomenclature (what does A0 mean?) and increased overlap with other EDA product lines. As is, figuring out which of Moto's many handhelds fits the bill requires hitting the spec sheets pretty hard.

Below you can see Motorola's Sheldon Safir introduce the MC55A0:

Also, thanks to Mr. Safir