Friday, September 16, 2005

As chip speeds max out, where next?

"But if you're planning to send a computer on, say, a 10-year mission into deep space, then you need more staying power. The best option used to be to send lots of spare processors and cross your fingers. As your probe flew silently through the night, you would dream about chips that could fix themselves.

It's not crazy. A type of processor called a field programmable gate array really can recover on the fly. Invented in 1984, FPGAs don't have hardwired patterns of circuits. Instead, their wiring runs through programmable intersections called logic blocks. They're slower than ordinary chips, and until recently their high cost limited their application to rapid prototyping of chip layouts. But advances in fabrication are finally lowering the price."

The Voyager and Viking probes used a unique chip (RCA's 1802) consisting of silicon mounted on sapphire, to 'harden' it against the extremes of temperature, electrostatic discharge and radiation to be found in the vacuum. This chip has been running since the 1970s and will keep running until around 2020, when its power will fail. Why bother having self-repairing chips, when you can have ones that are reliable (rather than our weak, cheaply manufactured commercial products.)

Moreover, space, because of its inhospitality, is a place where we can try out all those strange techniques that won't work anywhere else. What are the chances of something shorting or air oxidising the parts? Small, with a vacuum when you've got a truly closed circuit. With a temperature approaching absolute zero, all those superconductive materials our scientists develop in the labs (but will work nowhere else) should work perfectly. All our computers should be in space!

Sorry, I don't know why I'm writing about this, but I find it fascinating. I'd also like to emphasise how much I want to visit Mars.

7 comments:

Iain said...

I want to go to Mars too. I know that the trip would give me about a 90% risk of cancer due to the extreme level of radiation between here and there, but it'd be worth it just to stand on another planet.

If you've not read the Mars trilogy by Kim Stanley Robinson yet, you really should. There's a lot of hard science in there, and it's a great story to boot.

Grill said...

Maybe they could coat us in sapphire and silicon as well? >_<

Yeah, I've read the first one of those; good but I can't keep reading it for two reasons.

1) The lovable communist feller dies.
2) It drags everything out so... much... Borges or Philip K Dick or (especially) Olaf Stapledon lay the science faction down quick and hard, and don't bother with the flim-flam that Epic-writers like Kim Stanley, Robert Jordan and Tolkien fill up pages and pages with. Don't get me wrong, I like their stuff, but I've only got 50 years left here, at most...

Katrina said...

Great info. I've now subscribed to this blog feed so I can access it within my design prototyping site. This will make your blog one click away for me.

Katrina said...

Do you have an Rss feed to subscribe to? Im learning how to install an Rss reader and I'm learning. But it seems that I've been juggling the learning of rapid prototyping cnc and development in general. I'll get it working though.

Katbo said...

Great info. I've now subscribed to your blog feed so I can access it from my sheet metal prototyping site. I should make it easier to read when I'm busy. Thanks.

Katbo said...

Great info. I've now subscribed to your blog feed so I can access it from my sheet metal prototyping site. I should make it easier to read when I'm busy. Thanks.

Katbo said...

Great info. I've now subscribed to your blog feed so I can access it from my sheet metal prototyping site. I should make it easier to read when I'm busy. Thanks.