The Ancient Computers Powering the Space Race
An anonymous reader writes "Think that the exploration of space is a high tech business? Technology dating back to the Apollo moon landings is still used by Nasa mission control for comms and the 1980s 386 processors that keep the International Space Station aloft."
Those "ancient" 386 chips are probably mil-spec radiation hardened chips, too. Good luck getting your 45nm quad cores to work reliably in space...
No sig today...
And the B-2 Stealth bomber has the equivalent of an Amiga 1000 running it. What is the point of this article? Critical systems require reliable, proven, hardened hardware, not flakey netbooks.
If they are not the fastest CPUs, who cares? They aren't playing half-life on these systems they are flying space shuttles, and if you can't tell the difference, do not work in the defense or space industries. CPU speed isn't the prevailing factor here, reliablility and a known/proven system is.
If telephones are outlawed, then only outlaws will have telephones.
I forget which sci fi author it was, but there is a book where one of the main characters is hired to analyze code of a failing satelite. And he says "Perhaps the cleanest most boring software he had ever seen, virtually bug free, and what bugs there were had 3000 pages of documentation."
The Revolution Will Not Be Televised
My first engineering job out of college was as an avionics engineer at McDonnell Douglas in 1996. We were designing avionics using a Highly Reliable Industrial (HRIP) M68000 CPU downclocked to a couple of MHz. The reason for this CPU choice was that it did exactly what was required for building an embedded system. Also the M68000 had/has a very long production cycle and would be around for many years to come, which is important if you need spare parts in the future. We used the minimum clock setting required to achieve the required performance and to reduce power consumption and thermal cooling requirements. Modern general-purpose desktop CPUs normally aren't good choices for single-task embedded systems because of their power consumption, short product life spans, and general feature overkill. You do not need a particularly fast CPU to perform basic guidance and control tasks or to run avionics computers. The PowerPC has been adapted for imbedded MILSPEC systems for example and it's about 10 years behind the "state of the art."
Largely this is a function of geometry. The smaller gates required for higher speed operation are also vastly more sensitive to imparted charge from ionizing radiation. Large slow chips are inherently more robust, so when you do things like Si on sapphire you get a lot of bang for your buck.
I don't doubt that a fast core could be RAD hardened, but the current generation of Core2 arch and ix arch from Intel/AMD/IBM are virtually impossible to make into a rad hardened build. You really would need to do a redesign with things like ECC registers and the demand for such chips is so low as to not be a profitable endeavor for any of the main players. Demand is satisfied by the RAD600/750 families (PowerPC 750 / Apple G3), so why invest gobs of money into R&D for a product that has little to no demand?
-nB
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