[hettygreen]

Replying to myself here - I decided to just actually go read wikipedia about this. Here's the answer:

<quote>

By default, when a processor is executing an instruction, its LED is on. In a SIMD program, the goal is to have as many processors as possible working the program at the same time – indicated by having all LEDs being steady on. Those unfamiliar with the use of the LEDs wanted to see the LEDs blink – or even spell out messages to visitors. The result is that finished programs often have superfluous operations to blink the LEDs.

</quote>

[Cthulhu_]

I love that, makes me want to build an analog PC and stuff. Or visualizers for system activity.

Yes I'd unironically watch defrag work.

[andruby]

That's a lovely unintended side effect of incentives :P