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Re: Flight Computers



On Monday 29 April 2002 18:13, Phil Karn wrote in "Re: [amsat-bb] 
Flight Computers":

> ...the number of people on this planet who are *really* good at
> writing IPS code can still probably be counted on the fingers of one
> hand. Writing IPS can be an arduous process, and there's never any
> such thing as a "minor" change when one teensy mistake, such as not
> keeping your thread "stack neutral", can be fatal to the whole
> system.
>
> And times have changed. The 1802 is starting to get scarce, but much
> more advanced CPUs are now available to fly in space. There are now
> many thousands of highly skilled C coders all over the world...

Oh, dear...I don't think making sure that an IPS definition doesn't 
mangle the stack is harder than making sure C code doesn't mishandle a 
memory pointer. 

Quite the opposite in fact.  

But being a Java fanatic myself, I don't want to start a holy war here. 
As I recall though, the last of the rad-hardened 1802s went into AO-40, 
and no more will be manufactured. So that's a non-issue; amateur 
spacecraft going forward *will* use another archetecture.

Here's an opportunity for "dummy spacecraft" to do some serious 
innovating--something like the LART http://www.lart.tudelft.nl/ might 
be worth a look for such a project. Stick a prototype up on a tower 
somewhere and operate it remotely for a few months. 

 73 de Maggie K3XS  

-- 
-----/___.   _)   Margaret Stephanie Leber    / "The art of progress  /
----/(, /|  /| http://voicenet.com/~maggie   / consists of preserving/
---/   / | / |  _   _   _    `  _AOPA 925383/ order amid change and /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_  FN20hd / change amid order."   /
-/ (_/   '  K3XS  .-/ .-/    ARRL 39280   /___ --A.N.Whitehead ___/
/____ICQ 7161096_(_/_(_/__AMSAT 32844____/ <maggie@voicenet.com>

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