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Re: 7 Minutes of Terror with 500.000 lines of Code.

Posted: Sat Aug 11, 2012 9:32 pm
by utopiomania
Congratulations to NASA, it landed as planned. Another fanrtastic achievement. :shock: :)

Re: 7 Minutes of Terror with 500.000 lines of Code.

Posted: Thu Aug 30, 2012 5:38 pm
by naw
luis wrote:As spikey said AFAIK they use vxWorks and C (at least in some past missions, don't know about this one).
Probably part of the reason is the hw is quite limited compared to the everyday PC.
http://en.wikipedia.org/wiki/Comparison ... ars_rovers
Not limited Hardware - hardened hardware, the environment (radiation / solar flares) messes up higher density chips running at higher clock speeds

Re: 7 Minutes of Terror with 500.000 lines of Code.

Posted: Thu Aug 30, 2012 5:53 pm
by naw
Zach wrote:...I realize moving up to higher level languages and frameworks, and pre-packaged modules and such makes it a lot easier to code and all that, but still...
high level languages and frameworks introduce bugs, dependencies and unoptimised code. The only reason for Frameworks is to hide complexity, NASA don't want to hide the complexity - they want to know exactly what is happening, using frameworks would potentially add 1000,000's of lines of supporting code
Zach wrote:Seems like they might as well have just slapped an i7, 16GB of ram, and a GPU in there and called it a day.
it just wouldn't survive the launch / space / mars entry - all those CPU transistors and memory would be full of holes

[quote="Zach]I hope they at least did some optimizations somewhere or other..
500,000 seems like a big number to me.. I know complex programs can be several million lines, but I don't think I've seen anyone post here about a program nearing even 500k lines.[/quote]

The 500k lines of code which probably includes a bunch of assembler at 1 instruction per line

Re: 7 Minutes of Terror with 500.000 lines of Code.

Posted: Thu Aug 30, 2012 8:07 pm
by luis
naw wrote: Not limited Hardware
Yes, limited hardware, as I said compared to the average everyday PC. Less powerful cpu, slower clocks, less ram, etc.

The reasons were obvious.