The Desktop Rover, from Plantraco, is four inches long, charmingly cute, and utterly without purpose. The fact is, the Desktop Rover is a toy. And, if I may admit this without damage to my reputation for sobriety, it's fun.

• Plantraco web site

The $60 Desktop Rover is a tiny tank, about the size of your palm, an inch-and-a-half in height, and slightly heavy. On each side of it are four wheels and a horizontal guide, with rubber treads running round them. One of the wheels on each side is a gear, to drive the tread; each gear is driven by a small electric motor. Each motor is either going forwards, going backwards, or stopped, and you steer by combining these: if both motors are going forwards, the Rover goes forwards; if one motor is going forwards and the other is stopped or going backwards, the Rover turns; and so forth.

The Rover is quite peppy. It goes 10 feet in less than 30 seconds, and is strong enough to climb a steep slope, such as your car windshield. The main obstacles it can't negotiate are bad footing such as grass, where it can't get traction, and sudden steep elevation changes, not because it can't climb them, but because when it does, its short length causes it to assume a near-vertical position, sufficient to flip it over helpless on its back -- a one-inch-thick book lying flat on the floor is too much for it.

Rising from the Rover is a six-inch piece of insulated wire -- the antenna. Yes, the Rover is driven by remote control. The transmitter is about the size and shape of a cigarette pack, and has two levers which you press forwards or backwards to control each motor. There's also a third lever for making the Rover "shoot." I'll talk more about that later.

The Computer Connection

The way this relates to Mac OS X, providing me with an excuse to obtain one of these little goodies for free so I could write about it for TidBITS, is as follows. Separate from the Rover, you can also obtain for $70 a CD-ROM and a small cord with a USB connector at one end. From the CD, you install software, called Telecommander, onto your computer; then you run the cord out the USB port and into the remote transmitter, and start up Telecommander. Now, instead of the levers, the transmitter is controlled by the software.

It's fairly simple software, but not trivial. Nine buttons represent the nine possible combinations of motor behavior -- both motors forwards, one motor forwards and the other off, and so on. In "manual mode" you simply click a button and the Rover responds briefly, then you click another button, and so on. In "default mode," clicking a button causes its action to appear as a tile in a large composition area. A sequence of tiles in this area represents a sequence of actions you want the Rover to perform. The tiles can be rearranged, cut and pasted, deleted, and so forth; each tile also has a time value, which you can edit. Pressing the "play" button causes your sequence to be sent to the Rover; you can also save a sequence as a "macro," where a single tile represents the entire sequence.

Now, to call this programming, or even educational, would be something of a stretch. There are no tiles for looping and branching, so all you can do is play your sequence of tiles straight through. Nevertheless, our scientific test subject, a 13-year-old boy abducted from a neighbor's house, was entranced. He understood the program instantly, and promptly spent nearly an hour writing and refining an assigned sequence to negotiate a small course laid out on the floor with found objects. He also had a great time just playing outside with the Rover, making it climb around on dirt mounds and such. The result was a sizeable portion of the afternoon not spent watching television or playing electric guitar. After consultation with the boy's parents, I am officially authorized to declare this toy a resounding success.

Telecommander, by the way, is a Java application, which is why it requires Mac OS X. It comes with all the baggage that being a Java application usually entails: it's sluggish even on a 600 MHz PowerPC G3-based Macintosh, so that simple actions like selecting a tile or editing its time value take forever; and of course it has a non-standard interface, with the menus inside the window. On the other hand, it's cross-platform; I installed it on my neighbor's Windows NT box and it ran identically to my Mac. A nice feature is that the software is self-updating; if you're connected to the Internet when the software starts up, it checks to see if a new version of itself is available, and downloads it if so. Unfortunately this feature isn't clearly documented and is purely automatic; there is no Check For Updates menu item.

Other Extras

Also available from Plantraco is a miniature video camera module; you snap the upper half off the Rover and snap the camera module in its place, adding perhaps an inch to the Rover's height. The camera broadcasts a UHF signal (channel 16 or 19) that can be received by any nearby television. Thus, you could watch the television and control the Rover remotely without being able to see the Rover itself; in theory you could even feed the television signal into your computer and control the Rover from Telecommander, for an all-computer experience. Unfortunately, my influence as a reviewer was insufficient to merit a free sample of this module (my description of it is based on Plantraco's pamphlets and QuickTime movies). That's probably just as well, since I've no office mates to send the Rover round to spy on - though I could easily envision strapping a flashlight to the assembly and sending it down some gopher holes in my back yard.

Another feature I didn't get to try, because it requires a minimum of two Rovers, is the built-in laser tag game. The idea here is evidently that you shouldn't be the only person in the office goofing off -- everyone should get involved. The third lever on the transmitter, you may recall, controls the Rover's "gun," which makes a noise like some Star Trek weapon, but is actually an infrared light. If this light strikes another Rover, that Rover emits a "hit" sound. Transmitters and Rovers come in one of four different frequencies, so a four-way battle is possible. The rules of the game are dictated by the Rover's on-board electronics: after six shots, you must pause to "reload" by pulling the gun lever backwards; if you try to shoot faster than one shot per second, all your ammunition is expended instantly, requiring a reload; and if you receive 10 hits, your Rover is disabled until you physically power it off and on again. As the documentation notes, the penalty for losing the battle is thus that you must get up out of your chair to reset the Rover.

Yet another extra feature, which I did get to try, is a kind of doubly remote control. It turns out that the Telecommander software consists of two threads: the user interface thread, and an invisible background thread that communicates with the USB port. This background thread is actually a tiny TCP server running on port 1111; when the user asks to send a command to the Rover, the user interface thread functions as a TCP client to communicate with the server thread. The implication of this factored architecture is that you can drive the Rover using Telecommander software on a different computer, over the Internet! (Unfortunately, Plantraco does not publish the protocol used, so you can't write your own client software.)

I don't have two Internet connections in my house, so instead I made a miniature network by assigning my computers fake IP numbers and connecting them directly via Ethernet. On the machine with the USB cable running to the transmitter, I started up Telecommander and put it into "server mode," disabling the user interface. On the second machine, I started up Telecommander and put it into "remote mode," telling it the IP number of the other computer. Sure enough, I was then able to drive the Rover from the second machine -- the commands were going across the network to the first machine's copy of Telecommander and from there out the USB port.

You can test this feature yourself, right now, through one of Plantraco's Web pages. When you click the "Care for a Test Drive?" option, another page with a Java applet loads, and you are shown a webcam view of a Rover at Plantraco's offices. If someone else is playing, you're put in a queue; when your turn comes, eight control buttons will appear. If you're lucky and no one else is playing, the control buttons appear right away. Press a button and wait a couple of seconds; the Rover will respond and you'll see a new image showing its current position. It's fun and easy. This Web-based Java applet is not the same as the home version -- it involves a webcam, and it's using HTTP through a Web server and a browser, not two copies of Telecommander -- but it gives you the flavor of controlling a Rover across the Internet. To use the home version to control a Rover you can't see, I suppose you could run a webcam and Apache on the server machine, and the client machine could run Telecommander and a web browser, as described by Adam in "Driving FireWire Webcams in Mac OS X" in TidBITS 619; but I didn't have a webcam to try it with.

Icing on the Cake

A toy is largely imagination, and the Desktop Rover is no exception. It's not a Mars Rover, it doesn't go very fast, the remote-control "communication" is almost ridiculously simple, and you're (probably) neither a NASA scientist nor an astronaut. Nevertheless, there's something alluring about the Rover. I don't know what component of our psychological makeup subconsciously causes us to want to animate small scurrying things, but the Rover certainly brings it into play; the darned thing is so cute as it huffs and puffs its way towards you across the room and stops at your feet. Moreover, the illusion that the Rover somehow represents something larger and more technologically sophisticated is delightfully perpetuated by Plantraco's marvelous sense of humor and of design.

For example, both the Rover's top half and the transmitter are made out of translucent blue plastic, suggesting the original iMac's computer iconography. The transmitter is covered with pictures of the Mars surface, it's inscribed with a warning "For Use on Planet Earth Only," and its on/off switch is labelled "Groove" and "Snooze." The box, which describes the Rover as "Yoga for the 21st Century Ubergeek," is covered with true but somehow amazing exclamatory claims as to the Rover's powers (such as "Explore the Alien Landscape around Your Home!"), and contains photos of several mad scientists, along with the obligatory gorgeous babe who is draped head to toe in an astronaut suit so that only her eyes are visible. The Telecommander software starts up with some appropriate interterrestrial launch noises, and while you're using it, unnecessary technical-sounding status messages scroll by, some real, some bogus:

Mouse clicked
nautical miles (34,584 km)
Lexan shield
High Gain Antenna (HGA) on
Starting client communications
Opening
Socket[addr=localhost/127.0.0.1,port=1111,localport=49352]
Length is 25
Data is 10
Finished writing data 10
Reading acknowledgment
Roger. Good morning.

In short, Plantraco gives you a feeling that they're having a great time, and that they want you to have one too. While you're having a great time you might want to look into some of their other products; they also make a remote-controlled fan-driven helium-filled mylar blimp that can float from room to room, optionally carrying a miniature camera so you can spy on your office-mates. I want one.