PC/104 and others: The fork in the road between desktops and embedded

I first learned about PC/104 sometime around 1994. Back then my world was 6U and larger cards stuffed into boxes the size of foot lockers. I found it incredibly cool that a desktop PC could be built by stacking together a bunch of tiny PCBs like big Legos. Not only that, this PC/104 “personal computer” thing could also add additional and custom I/O. At that time, I was working for a military integrator and the prospect of adding I/O modules for MIL-STD-1553, ARINC-429, and weapons stores to a cube-like PC/104 stack was very compelling. It still is.

If you check out this month’s product guide on rugged, industrial, and MIL-SPEC products (page 38), you’ll see that all kinds of small form factors target non-benign applications. Increasingly, I’m seeing PC/104 and other Computer-On-Module/System-On-Module (COM/SOM) products geared towards what are certainly not desktop PC applications. Yet, PC/104 and many of the other flavors we cover in PC/104 Embedded Solutions magazine have their origins in the desktop space.

It’s the rugged markets that are impaling PC/104 and other small form factors squarely at the fork in the road between tomorrow’s desktop functionality and the more specialized application-specific variants. Which way will the industry go?

Playing it “PC”
On one path is the desktop market, which has been mostly stagnant for the last couple of years in terms of technology and unit growth. That’ll change soon. Since module standards such as PC/104, EPIC, ETX, Mini-ITX, and others have their roots in the PC space, there will soon be pressure to adopt a whole truckload of new “desktop” multimedia features, software, and inter-networking pipes.

Pentium M-based single board computers are now showing up in our PC/104 database. It wasn’t long ago that standards such as PC/104 only offered x86 processors such as AMD’s Geode, VIA’s Eden, or other variants. Why? Intel’s Pentium 4 and Pentium 4m CPUs burned too much heat that couldn’t be dissipated on smaller boards. When Intel introduced the Centrino series of Pentium M, Ultra Low Voltage (ULV) Pentium Ms, chipsets, and wireless devices, suddenly the newer 30 W+ devices were “feasible” on smaller modules again.

From the desktop, laptop, and metropolitan space also comes wireless connectivity, first with IEEE 802.11b, then a, g, “pre-n,” and soon “n” and 802.16 WiMAX flavors. It’s alphabet soup, but consumers now demand wireless connectivity in laptops, PDAs, and game consoles. Users can add Wi-Fi SDIO cards to all kinds of battery-operated doodads, and the home entertainment PC concept seeks to connect all kinds of wired and portable devices into a computer-based home network. In addition, the equipment need not be limited to a traditional PC, as set-top boxes, video recorders, and now Intel processor-based iMacs get into the game. These devices are all fundamentally based upon PC processors, peripherals (think USB 2.0), and memory such as flash-based thumb drives.

A lot of this embedded interconnectivity is going to find its way onto traditional PC/104 and other small form factor modules, as is the software, be it Microsoft’s Vista, Intel’s Viiv API, Apple’s OS X (or “OSx86”), or a Linux distribution. Check out what VIA is doing with some of their new Mini-ITX modules on page 32.

Embedded or not
On the other path are those rugged applications that demand performance in a small space, low power dissipation, fanless operation, and custom I/O. Companies such as motor controller expert Calmotion (page 20) have married PC/104’s size with programmable microcontrollers to realize cost-effective heavy industry motor controls.

Non-benign applications may shy away from the latest consumer whiz-bang hardware such as AMD Athlon64 processors, not because they can’t be practically cooled – don’t even think of it on a PC/104 board – but because long life and backwards compatibility with 32- or even 16-bit code (think 80186) is imperative. And while Asynchronous JavaScript and XML (AJAX) may finally replace the security nightmare of ActiveX in desktops, rugged embedded modules may run code and security features in the Nucleus RTOS from Accelerated Technology. For PC-like functionality, Microsoft’s updated Windows XP Embedded distribution will remain a better choice than XP.

Stuck in the middle with you
Which way will PC/104 and other small form factors go? Will they follow their roots and consciously trail behind tomorrow’s connected multimedia desktop, or will they continue to take market share in rugged apps from CompactPCI, VME, and mezzanines like PMC? One thing’s for certain: It’ll be interesting to watch over the next 12-18 months.