Thread: Iphone VS N900
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electroaudio's Avatar
Posts: 381 | Thanked: 336 times | Joined on Jan 2011 @ Stockholm, Sweden
#44
Originally Posted by bass800 View Post
so apps are the main reason for owning a phone or any device aside from the hardware. ie. windows os = avid, osx = final cut / different strokes for different folks. but these are apps. apps are not only games. n900 may have been an ok device with ok hardware with ok apps, but sorry to burst your bubble but its over, just like the 286, 386, 486 and webos.
If you believe 8086-286 is dead then you are completely wrong.
http://www.intersil.com/product/deviceinfo.asp?pn=80C86

http://www.intersil.com/products/dev....asp?pn=80C286

A lot of these processors you call dead are still alive and well, and you probably use many of them on a daily basis without knowing it...

Next, when you mention Avid, the recording industry uses a lot of 386 and 486 computers, because they are the only ones than can host the hardware and software used by their favourite mixingdesks.
The industry also has a lot of specialized robots and other machines that utilizes 8086-486 computers and works just as well today as they did when they were new.
Even Nasa uses older technology in their equipment because it does the job needed, with the best performance.

Originally Posted by NASA question board
QUESTION:
When it was designed, why was only a single 80C85 CPU used? Why did not you go for a powerful CPU which would have increased the computational power of the Sojourber rover?
Does it have such a small instruction set that it does not need more resources?

ANSWER from Mark Adler:
The answer is money and mass. We had $25M and 25 pounds to work with so we had to choose something cheap, low power, and also space qualified/rad hard.
The 80C85 is good enough for our purposes. Since we can't move very fast anyway because of power limitations, we don't need to think very fast. The Pathfinder lander uses a hot computer - an RS6000, and the 2001 rover will also have a more competent computer.

Yours,
Mark

ANSWER from Steve Stolper:
This is a good question and exposes a "little secret" of the space business. While many associate spacecraft have high technology, traditionally spacecraft have been built using old technology. This mission is one of the first to use "state-of-the-art" technology on board.

Processors on spacecraft must withstand severe thermal, vibration, and radiation environments. In addition, they must consume very little power.
These processors are much more difficult to design and build. As a result, radiation-hardend space processors have always lagged behind the "state-of-the-art." That is why the rover computer is an 80C85. This is a very low-power, radiation-hard, processor.

The lander computer (RAD6000-SC) is a 22 MIP machine with 128MB of RAM and 6MB of EEPROM. It runs a multi-tasking operating system and is the most powerful processor flown in the planetary program. The processor can withstand -55C to +70C temperatures. On impact, the lander flight computer pulled 18g's and has not been effected by radiation encountered during the 7
month cruise to Mars.
 

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