With all the talk these days about advanced, high-performance backplane form factors for telecom computing such as AdvancedTCA (News - Alert), MicroTCA, CompactPCI and VME, we forget that good old motherboards are still found in many telecom-related devices, if only because they cost less than full-sized passive backplanes.

 

Routers, switches, firewall boxes, Web servers, 1U and 2U rackmounts—all of these have at one time or other been based on Ye Olde motherboards. Indeed, motherboards appear in all five “classic” market sectors for embedded applications: telecom/networking, industrial automation, gaming, medical, and transaction terminals.

 

In an age where the size of a device or appliance is important, passive backplanes are glossed over in favor of motherboards for various reasons. Passive backplanes slots are closer together than those on a motherboard. A reduced height system may force the system designer to devise something with a CPU card that's so fat that the slot next to it must remain ‘depopulated’, unless you use low-profile memory modules, which can bump up the cost.

 

Single-board computers also tend to have smaller surface areas than motherboards, so more electronics must be packed into a smaller package, which in turn makes the smaller board more expensive to produce. More crowded components pose greater cooling challenges. You need bigger fans. While you often have to blow hurricanes through passive backplane systems, you can use much less expensive fans with motherboards; indeed, you can eliminate fans entirely on some motherboards and use passive heat sinks instead. This means you might be able to extend the life of the board to as long as eight years, according to my friends at RadiSys. Then, of course, one must consider all of those cable connectors crammed onto a small rear end of one CPU card; a motherboard spreads these out over a more manageable area. 

 

So, embedded systems really favor the use of smaller motherboards. Normally, the term "embedded computer" brings to mind the PC/104, PC/104-Plus and EBX form factors, but some of these are too small for the more powerful embedded applications that keep appearing.

 

Fortunately, other the years there has been a profusion of motherboard sizes, all based around current (or former) industry standard form factors such as ATX (full sized, holding about four PCI and three ISA slots), microATX (smaller), FlexATX (a very low cost offshoot of microATX that's about 25 percent smaller still) and the not-too-successful NLX which is about the size of a microATX but allows for quick processor upgrades, faintly reminiscent of the way a CPU board can be replaced in a passive backplane system.

 

In 2001 the Mini-ITX appeared, a low-power motherboard form factor developed by VIA (News - Alert) Technologies. Mini-ITX shares some characteristics with ATX, microATX, FlexATX and BTX form factors, but it much smaller: 170 mm (6.7 inches) by 170mm. Because of their low power consumption, many Mini-ITX boards can be passively cooled, so there’s no fan noise, a great advantage when used with home theater systems.

 

Recently, Advantech (News - Alert) introduced the AIMB-253L, an Intel 945GM-based Mini-ITX motherboard that supports advanced dual core processor technology. The integrated Intel GMA 950 graphics controller features 256 MB of shared video memory and DirectX 9 3D hardware acceleration. For multiple displays or future graphics upgrades, a PCI Express x16 slot supports higher performance graphics cards that permit a relatively easy connection to various display devices like CRTs and LCDs.

 

The AIMB-253L offers various integrated I/O interfaces that speed up installation and deployment. For example, it offers dual LAN connectivity; the PCI Express based Intel 82573 Gigabit Ethernet controller delivers up to 1000 Mbps of bandwidth for network-intensive applications.

 

The AIMB-253L also has two Serial ATA II 300 Mbps connectors for data storage. Graphics and I/O expansion are supported by the PCI Express x16 and 32-bit PCI slots. The AIMB-253L promotes an expedient connection to external peripherals through four USB 2.0 ports; three RS-232 and two RS-422/485 ports; one parallel port; LVDS and VGA ports and one PS/2 port.

 

The AIMB-253L should be suitable in such diverse applications as gaming, infotainment, kiosk, POS, medical, transportation, business, education and embedded markets. Integrated graphics is provided by the Intel GMA 950 graphics core. The Intel GMA950 graphics core supports up to 256 MB of video memory. The AIMB-253L also has Intel 7.1 channel high definition audio via an S/PDIF output. It should be terrific for customers needing dual display and high quality graphics support. The AIMB-253L supports Microsoft (News - Alert) Windows XP, 2000, XPE and CE operating systems. It board is available now.