I love it.

Note that there's more truth in this fantasy than one might think, at least potentially. IXM nodes don't have the ability to fry each other, but they do supply each other with power, and that power switching is under software control.

So in many configurations, IXM nodes absolutely and literally do have the power to reach a consensus about a misbehaving neighbor and shut it down.

David Ackley brags, "We have a CPU, RAM, data storage and serial ports for connectivity on every two square inches."

Well, I want to say "No brag just fact."

Except it's not quite fact: What I actually said was "under two inches squared" -- which is closer to four square inches.

But hey, I'm glad I didn't say "under 50mm squared".

Also, the specs got a little muddled. The raw hardware on the current board has 58KB RAM, 512KB flash for program store, and 16KB EEPROM for data.

I'm part of the project that produced this board.

I am definitely, yes, old enough to remember the Transputer. And I hacked artificial life models on the MasPar in the early 90's, which had an architecture in some ways similar to the Connection Machine.

Although the IXM is indeed 'embarrassingly suitable' for assembly into planar grids, it certainly isn't restricted to that. With right angle headers, for example, it's easy to make shapes likes rings and cubes and so forth.

When the global computational geometry of a machine is fixed at design time, before the ultimate task is known, routing can easily become a major problem. And general routing is hard. Maybe too hard.

But part of exploring modular systems in the 'physical computation' space is trying to figure out ways to make the geometry of the particular computer you build better fit the behavior you're implementing, which can help ease the general purpose routing problem.

And if one really gets into a corner, well, ribbon cable is cheap.

robots as well. To correct for this, one would want to put a sensor which senses the rotating shaft on the motor -- keep rotating motor until it's gone through the proper amount of degrees instead of just

Well, it's possible that this was a non-standard add-on done before I got to it, but when we hacked on a big trak as a summer hardware project in school, that one at least had photocells looking through the teeth on the track drive gears.

So you didn't have to dead-reckon track distance from motor runtime; instead you debounced the photocell output and counted gear teeth passing. You could and did still get screwed by various amounts of slip between the track and the floor, but variable motor speed wasn't as much of an issue.