[rescue] NTP and Fuzzballs, was Re: Linux wet paint, was Re: Spark10 CPU question (must fix - SPARC damnit :-) )

Carl R. Friend crfriend at rcn.com
Fri Dec 23 16:52:47 CST 2016

On 12/23/2016 05:24 PM, Dave McGuire wrote:

>   Yes.  But my desktop doesn't sync to my GPS receiver, it syncs to the
> computer that's wrapped around it. ;)  (Datum Tymserve 2100)

    My stratum-1 can be used as a desktop if I fire up an X-terminal
or other display system for it.  I wanted to "do things the hard
way" when I set the thing up and actually paid a premium for a box
that had a BNC nozzle for the antenna, an RS-232 nozzle to talk to
the computer, and a power jack.  So, that's the stratum-0 device,
and it's in a separate box.  (Likely your "appliance" uses something
entirely similar "under the covers".)

    The device it's attached to is an old Pentium Pro motherboard
living in an older Gateway 2000 box.  The interrupt chain is simple
enough so the thing doesn't jitter too much and the long-term
offset averages in the 25 nS range.  Newer systems will do worse
because of the convoluted interrupt architecture and don't stand
a chance with USB <-> RS-232 converters.

[CRF]>    At some point, I really want to try lighting up a fuzzball.
>   Me too!  Let me know if you decide to finally get to that; maybe we
> could do it collaboratively.

    I've got period-appropriate iron that runs, so that's a no-brainer.
It's the time to actually execute.  Also, the version of NTP that'd
run on the fuzzball would not understand a GPS receiver without a
massive rewrite and I'm no longer up to doing a WWV clock, nor do I
have access to space for a proper antenna.

>   (that's on-topic!)

    These things sometimes happen.  I need to revisit the fuzzball
idea at some point.  I really do.

| Carl Richard Friend (UNIX Sysadmin)            | Boylston            |
| Minicomputer Collector / Enthusiast            | Massachusetts, USA  |
| mailto:crfriend at rcn.com                        +---------------------+
| http://users.rcn.com/crfriend/museum           | ICBM: 42:20N 71:43W |

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