Internet Appliances with a Twist

Adomo uses a client-server approach.

Adomo ( wants to fill your home with a network of low-cost, easy-to-use information appliances. Best of all, they'll each have Linux inside.

Adomo's plans are to transcend the boundaries of the PC revolution, making home information appliances as easy to use—and ubiquitous—as microwave ovens. To accomplish this, they chose to redefine the very nature of home information systems. They started out by asking, “What do family members really want?”

A “Back to the Future” architecture.

That quest led to a product architecture that runs counter, in many ways, to the current PC paradigm. Contrary to the popular notion of intelligent interconnected appliances as the wave of the future, Adomo's architecture is a lot like the “pre-PC” multi-user computers and dumb terminals of 25 years ago—but with some important differences.

Adomo's solution creates a home network that consists of two types of devices: a highly intelligent central device (the “server”) which provides computing, information storage and Internet access resources; and multiple wirelessly linked user-interface devices (“clients”) distributed throughout the home.

But there's an important twist: although the user-interface devices function like intelligent information appliances, they don't actually run any application software internally. They just pass data back and forth to the central server.

This approach can work—since today's high speed networks can provide near-instantaneous access to massive amounts of computing power and vast quantities of data. In other words, as Sun puts it, “the computer is the network”. That being the case, the distinction between server and client becomes moot!

This way, the CPU within the appliance needn't be capable of running sophisticated programs. Its main purpose is managing input/output functions, which are mostly user-interface-related. Each appliance runs just one program: a reduced-footprint version of the X Window System. All the application programs run on the central server. Only display output (graphics, sound) and user input (keyboard, mouse, sound) travel back and forth between the server and the appliances.

Thin Is In

By restricting their function to input/output only, Adomo's extremely “thin” information appliances become simplified to the point where they are mere interface terminals rather than computers (even though they do contain microprocessors). This has some interesting consequences.

One is that changes in context—between family members, or between OFF and ON—are nearly instantaneous. Since the appliance is just an interface to software running on the server, all appliances can be used interchangeably. Just sign on, and pick up where you left off. No need to wait around while the OS inside the user interface of a refrigerator or microwave logs out one user, and prepares itself for access by another.

Another big advantage of extremely thin appliances is that they're smaller and cost less. Also, they generate less heat, and run longer on a battery charge.

An interesting side effect is that because the appliances don't contain their own application software, there is hardly anything to go wrong from a software perspective. All they need to do is be able to load their operating software from the server, across the wireless LAN. That, plus their accompanying electronic simplicity, means the appliances are likely to be completely free from the headaches of maintenance and administration—or at least that's the plan.

Even system administration is simplified, since all software for operating the entire home system is concentrated on the server, a Linux system. That should make remote maintenance and support a snap.

Of course, for the Adomo client/server scheme to work, the server had better be powerful enough to handle the activities of all the client devices located throughout the home. Also, the wireless LAN needs to have sufficient bandwidth to carry all the associated data transfers. Adomo claims the performance of their server will support the simultaneous activities of up to eight “typical” family members.

Does that include teenagers playing the latest video games? Probably not. For that reason, Adomo also lets you use one or more normal PCs on the network. In that case, the Adomo server provides connectivity, application sharing, file storage and backup for all devices—both PC or non-PC.

The Server

The Adomo server is functionally similar to a high-end PC running Linux. But, as you can see from the photo (see Figure 1), it looks more like an appliance (possibly an air conditioner) than a PC.

Figure 1. Adomo Server

Inside, there's a custom motherboard based on an AMD mobile K6 processor. Adomo's engineers took advantage of laptop-like components in designing the server, to reduce power consumption and heat dissipation. This lessens the need for noisy fans, and should boost system reliability.

The server is a multi-tasking, multi-user computer system that provides a variety of shared resources and managerial functions, including those of Internet gateway, firewall, e-mail, file storage and system backup. And don't forget: all application programs for all client devices run on the server, not on the devices.

Although the server isn't promoted as such, you can add a monitor and keyboard and use it as an additional desktop system. In that case, it will run all the same application programs available to the client devices.