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Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA)

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"Retrohc" <retrohc@yahoo.it> ha scritto nel messaggio 
news:ad4052df-a79e-426f-9c2e-d70536afa20d@googlegroups.com...
Il giorno domenica 6 marzo 2016 11:17:52 UTC+1, Gabriele Banorri ha scritto:
> Ciao,
>    il sito Muckrock ha lanciato una campagna per trovare il computer
> piu' vecchio ancora in uso in un qualunque ente del governo americano:
CUR

Ma se intende il computer più vecchio in assoluto ancora funzionante, credo 
che occorra pensare a quelli funzionanti a bordo delle sonde Voyager in 
funzione dal 1977, si  tratta di computer con processori RCA a 6,3 Mhz.
Saluti.
.      Mauro

---
Grazie Mauro per avermi incuriosito,
un clock ci CPU da 6.3Mhz per quel tempo non mi convinceva,
specialmente per dispositivi a basso consumo
e dalla extralunga durata.

Così leggo dal sito Nasa:  http://voyager.jpl.nasa.gov/faq.html
circa dopo la metà di FAQ ( seconda stella a destra, questo è il cammino...)

<< the computers were manufactured by General Electric to JPL specifications 
 >>
<< but the CPU's clock runs at only 250 KHz  >>

Roby.


Question: What kind of computers are used on the Voyager spacecraft?



Answer: There are three different computer types on the Voyager spacecraft 
and there are two of each kind. Total number of words among the six 
computers is about 32K.

Computer Command System (CCS) - 18-bit word, interrupt type processors (2) 
with 4096 words each of plated wire, non-volatile memory.

Flight Data System (FDS) - 16-bit word machine (2) with modular memories and 
8198 words each

Attitude and Articulation Control System (AACS) - 18-bit word machines (2) 
with 4096 words each.

According to my calulations, that's a total of about 68KB, or small potatoes 
compared to today's microprocessors. We probably could perform all functions 
with one of today's boards and still have room for solid state data storage 
and much more fault detection software. We would still need a second unit 
for redundancy. Today's microprocessors are also much faster than the chips 
used on Voyager and a comparative system would use less electrical power. On 
the other hand, software might be more complicated as opposed to that used 
in an interrupt type system, but it would be much more capable and more 
flexible.

Let's look closer at the CCS. The CCS has two main functions: to carry out 
instructions from the ground to operate the spacecraft, and to be alert for 
a problem or malfunction and respond to it. Two identical 4096- word 
memories contain both fixed routines (about 2800 words) and a variable 
section (about 1290 words) for changing science sequences. The CCS issues 
commands to the AACS for movement of the scan platform or spacecraft 
maneuvers; to the FDS for changes in instrument configurations or telemetry 
rates and to numerous other subsystems within the spacecraft for specific 
actions. Fault-protection algorithms are also stored in the CCS, occupying 
roughly 10 percent of the CCS memory.

The main functions of the FDS are to collect data from, and controls the 
operations of, the scientific instruments; and to format engineering and 
science data for on-board storage and/or real-time transmission. The FDS 
also keeps the spacecraft "time" and provides frequency references to the 
instruments and other spacecraft subsystems.

The Voyager spacecraft computers are interrupt driven computer, similar to 
processors used in general purpose computers with a few special instructions 
for increased efficiency. The programming is a form of assembly language.

There is no clock chip, as such, in the spacecraft. The "clock" is really a 
counter, based on one of several electronically generated frequencies. These 
frequencies, based on a reference, generated by a very stable oscillator, 
are converted and fed to different locations in the spacecraft as 
synchronization signals, timers, counters, etc. The "clock" signal is part 
of the information telemetered to the ground and it is with ground software 
that we convert to day of year, time of day Greenwich Mean Time.

Voyager was built in-house at JPL; the computers were manufactured by 
General Electric to JPL specifications.



Question: How fast are the Voyager computers?



Answer:Not very fast compared to today's standards. The master clock runs at 
4 MHz but the CPU's clock runs at only 250 KHz. A typical instruction takes 
80 microseconds, that is about 8,000 instructions per second. To put this in 
perspective, a 2013 top-of-the-line smartphone runs at 1.5 GHz with four or 
more processors yielding over 14 billion instructions per second.

 

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La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Gabriele Banorri <banoPLEASE_REMOVE_ME@algasystems.net> - 2016-03-06 11:17 +0100
  Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Gabriele72 <arel72TOGLI_QUESTA_PARTE@email.it> - 2016-03-06 13:19 +0100
    Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) "dott.Piergiorgio" <chiedetemelo@ask.me> - 2016-03-07 23:05 +0100
  Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Retrohc <retrohc@yahoo.it> - 2016-03-06 06:04 -0800
    Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) francesco.messineo@gmail.com - 2016-03-06 07:01 -0800
      Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Retrohc <retrohc@yahoo.it> - 2016-03-06 07:21 -0800
    Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) "robby_1" <no_spam@alice.it> - 2016-03-06 19:26 +0100
      Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Retrohc <retrohc@yahoo.it> - 2016-03-06 13:44 -0800
        Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Gianluca Bonetti <gl@decadence.it> - 2016-03-10 13:13 -0800
          Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) Retrohc <retrohc@yahoo.it> - 2016-03-10 14:33 -0800
          Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) badwishSPAMMATUSORELLA@vodafone.it (Yellowpecora) - 2016-03-10 23:52 +0100
  Re: La ricerca del piu' vecchio computer ancora in funzione (nel governo USA) scap61 <scap6161@yahoo.it> - 2016-03-07 23:39 -0800

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