[time-nuts] Oscillator temperature compensation

[Hal Murray]

magnus at rubidium.dyndns.org said:
> On 06/22/2013 05:27 PM, Didier Juges wrote:
>> A real treat would be to do the GPS receiver with tubes ;)
> The the correlation channel(s) would be possible to do in tubes. The rest of
> the processing is "problematic". 

The IBM 709 was tubes.  (Well, mostly, they used transistors on the front end 
of the memory.)  Memory was 32K 36 bit words.  Call it 128K bytes.  That 
might be enough.

It had a cycle time of 12 microseconds.  12 ns would be 1000x as fast.  
That's 80 MHz, a reasonable speed for an ARM.  So the CPU in today's GPS 
systems is 300x to 1000x faster than the 709.

Anybody know what fraction of an ARM it takes to do the GPS calculations?

Do you have to keep up, or can you do the calculations for every N-th second?


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