What exactly IS an "Embedded PC" and what are its advantages?

5.25" PC motherboard - this is the Advantech PCM-9380 Here's the PC with MIO board attached being installed in the chassis
We've all gotten used to the various forms of PC -- palmtop, laptop, desktop. But "embedded"? What the heck is that? Turns out they are very common things, and you've probably used them without even realizing it. An embedded PC is simply a tiny, rugged PC that is meant to be installed inside an instrument. Agilent uses them inside its oscilloscopes, spectrum analyzers and other products that have built-in displays. Many point-of-sale terminals have embedded PCs in them.
We have chosen Advantech Corporation to provide our embedded PC. Advantech products have wide acceptance in the world, and the quality, feature set, price and support are very good. Although the company is based in Taiwan, they have American Sales Reps and support personnel. We have not had trouble getting excellent and timely support. If you have a problem with the embedded PC in your Sienna, we provide support to you directly, but it should be reassuring to know that we in turn can rely on the expert assistance from the Sales Reps and Application Engineers at Advantech.
Embedded PCs have these advantages over laptops and desktops:
1. They have a much smaller Operating System kernel. Terminals that are designed to insulate the user from the O/S often use Linux. Others, such as oscilloscopes, use Windows XP. The smaller kernel takes up less space on the disk, so small Compact Flash cards can be used instead of hard drives. However, the O/S is still fully compatible with all the applications you know and love. The embedded PC in the Sienna can be loaded with either XP or Linux. Windows 7 will be available eventually, but we expect XP to be in use for quite some time, simply because so many people are using it and it is a very good, stable O/S.
2. Embedded PCs do not take long to do a shutdown sequence before power is removed, and they also start up quicker. You know how long it takes to do a shutdown/startup as Windows closes/opens all of its applications. But in an instrument, the smaller kernel means that a shutdown and startup is much faster.
3. Because the embedded PC is inside the instrument, its wiring and power connections are all done for you. You don't have to lug around the power cord and interface boxes or cables when you move from place to place. The only thing you would have to take with you are the keyboard, mouse and monitor. Now you might say, "But wait! With a laptop that's all built in." And you'd be right, but you would still have to take any boxes along, such as sound card interface boxes, wall warts and interconnect cables. Laptops are also less affordable for many people. And because the radio is a radio first, you don't have to use the embedded PC. You can grab your Sienna and take it with you without taking any of the PC accessories, even if the embedded PC is present.
4. Choice of screen size. As with a desktop, you get to choose how large an external monitor you use. Although you can plug one into a laptop, you typically don't. When you plug a monitor into the Sienna, it can be a widescreen Plasma HDTV if you want! In fact, because the Sienna has an option for a MIO board, you can actually have two video displays at the same time - the standard high resolution VGA, and the even higher resolution DVI.
5. Backups and virus protection are not necessary. Although you could use the O/S inside the Sienna as your primary home PC, and use it to do your taxes, surf the web, and do pretty much anything you would do with a regular PC, you typically won't want to do this. For one thing, the size of the Compact Flash card (8GB max) precludes storing a lot of stuff (although you can easily add an external USB flash or hard drive or use LAN-based storage). But mainly, your Sienna is intended to run ham applications. By not using it as your main PC, you do not have to worry about virus protection, theft or loss of data. If something happens to the Compact Flash card with the O/S on it, you can simply call us and we'll send you a replacement card. If it's out of warranty, the cost to replace the card is about $100. We do recommend that you back up any data files that you store in the Sienna. This is really easy to do, too! As we just mentioned, you can plug a flash disk into the USB port and copy files quickly. You can also use the built-in Ethernet networking to make the Sienna look like just another PC on your home network and you can then simply drag and drop files from your Sienna to your backup drives.
6. The hardware platform of an embedded PC is very stable. They do not go obsolete as fast as desktop PCs because they are sold by the thousands to companies like DZKit and installed in products that need to be around for a long time. Since they are small and completely self-contained (sound card, I/O ports and everything on one little card), they are easy to upgrade too. You can access the SODIMM memory from the bottom of the Sienna by removing a cover plate, and you can pop the Compact Flash card out from the back panel, so these are easily upgraded as newer, larger memories become available.
7. Because they are dedicated to a given application, the speed of the processor is not critical. We offer two models - a Celeron at 1GHz and a Pentium Core 2 Duo at 2GHz. Even the DSP application software we install (SiliconPixels' ChromaSound) runs just fine on the lower speed CPU. You can buy bigger, faster CPUs for desktop and laptop PCs, but the performance is not necessary to run the typical ham radio application software, so there's no need to have the biggest, fastest CPU. Even the SDR-IQ receiver/panadapter, which does all the spectrum analysis on high speed data coming in over the USB port runs fine on the lower speed CPUs.
And one final word about the embedded PC in the Sienna:
The Sienna does not depend on the PC. Some other manufacturers who sell radios with embedded PCs rely on the PC to do all of the work. With the Sienna, we believe that you prefer to use the PC to augment the radio, not to BE the radio. As a result, if you aren't planning to use the PC for digital modes, logbooks, contest dupe-checking, mic processing, or DSP, you don't have to wait for it to boot in order to use your rig. The radio is controlled from its own dual Atmel Mega644P microprocessors with firmware that we've factory installed (and that you can update yourself). You control the radio by using front panel knobs, buttons and switches, not by clicking the mouse (unless you are using a front-panel-less Sienna, in which case you do need either an external or internal PC). You can run any of the popular rig control applications right on the rig if you want to. Ham Radio Deluxe will soon have Sienna available as one of the selectable radios.