On Sun, Dec 2, 2012 at 3:16 PM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
Erich,
On 12/02/2012 08:54 PM, Erich Heine wrote:
Jonathan,
My research group has had some good experiences using products from
Endace (
http://www.endace.com/) for network timing measurement at the
I'm an applications engineer for a company that makes Ethernet controllers
and PHYs. Some of our customers use crystals (more often oscillators) that
they selected based on price rather than performance. when i'm debugging a
customer issue replacing the clock source with a synthesizer is a good
My research group has had some good experiences using products from Endace (
http://www.endace.com/) for network timing measurement at the ethernet
level. I don't have a pointer immediately to the work, but if there is
interest can ask tomorrow at work. The gist of it though was to understand
Hi
Maybe I'm just shopping in the right places. I have yet to build up a desktop
machine that does *not* have at least one COM port on the motherboard. That's
been true all the way from simple little Atom based ITX boards right through
monster boards with all sorts of crazy stuff on them.
On Sun, 2 Dec 2012 08:43:39 -0500, Bob Camp li...@rtty.us wrote:
Hi
Maybe I'm just shopping in the right places. I have yet to build up a desktop
machine that does *not* have at least one COM port on the motherboard. That's
been true all the way from simple little Atom based ITX boards right
Hi
Strange - I must indeed have been lucky on the last dozen or so systems I built
up.
Bob
On Dec 2, 2012, at 1:14 PM, David davidwh...@gmail.com wrote:
On Sun, 2 Dec 2012 08:43:39 -0500, Bob Camp li...@rtty.us wrote:
Hi
Maybe I'm just shopping in the right places. I have yet to build
Jonathan,
My research group has had some good experiences using products from Endace (
http://www.endace.com/) for network timing measurement at the ethernet
level. I don't have a pointer immediately to the work, but if there is
interest can ask tomorrow at work. The gist of it though was to
Erich,
On 12/02/2012 08:54 PM, Erich Heine wrote:
Jonathan,
My research group has had some good experiences using products from Endace (
http://www.endace.com/) for network timing measurement at the ethernet
level. I don't have a pointer immediately to the work, but if there is
interest can
Date: Sun, 02 Dec 2012 22:16:52 +0100
From: Magnus Danielson mag...@rubidium.dyndns.org
On 12/02/2012 08:54 PM, Erich Heine wrote:
Examining the time in switch for various packets at the microsecond level
was needed to understand various delay curves for different network loads,
with an
Matt,
On 12/02/2012 11:51 PM, Matt Davis wrote:
Date: Sun, 02 Dec 2012 22:16:52 +0100
From: Magnus Danielsonmag...@rubidium.dyndns.org
On 12/02/2012 08:54 PM, Erich Heine wrote:
Examining the time in switch for various packets at the microsecond level
was needed to understand various delay
In message ecc7f999-673e-4f70-95ef-1d888761a...@rtty.us, Bob Camp writes:
It's most commonly done with things like a Soekris 45xx series board. You
don't need anything very exotic for the frequency conversion. The jitter in
the PC is way worse than what the external chips will be
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Hash: SHA1
Eric, your experiences here is of great interest to me too, I've been
exploring external clocking of Ethernet controllers as of late but
have not dived into it yet.
I'm more interested in your how, but of course also in your why.
// jwalck
PS. Hey
Originally the IBM PC design used an 8253 or 8254 PIT, programmable
interval timer, located at ports 40h to 43h with Timer 0 clocked at
1.193182 MHz (1/3rd of 3.579545 MHz or 1/12th of 14.318 MHz) and set
to divide by 65536 which generated about an 18.2 Hz interrupt rate on
IRQ 0. Timer 1
On 12/02/2012 01:29 AM, David wrote:
Originally the IBM PC design used an 8253 or 8254 PIT, programmable
interval timer, located at ports 40h to 43h with Timer 0 clocked at
1.193182 MHz (1/3rd of 3.579545 MHz or 1/12th of 14.318 MHz) and set
to divide by 65536 which generated about an 18.2 Hz
On Sun, 02 Dec 2012 01:53:07 +0100, Magnus Danielson
mag...@rubidium.dyndns.org wrote:
On 12/02/2012 01:29 AM, David wrote:
Originally the IBM PC design used an 8253 or 8254 PIT, programmable
interval timer, located at ports 40h to 43h with Timer 0 clocked at
1.193182 MHz (1/3rd of 3.579545
davidwh...@gmail.com said:
One of my favorite tricks back when the ISA bus was still available was to
use a custom expansion board I built and an oscilloscope to measure the
interrupt latency.
You can do the same trick without special hardware. Use the printer port.
Of course, that
On Sat, 01 Dec 2012 19:10:54 -0800, Hal Murray
hmur...@megapathdsl.net wrote:
davidwh...@gmail.com said:
One of my favorite tricks back when the ISA bus was still available was to
use a custom expansion board I built and an oscilloscope to measure the
interrupt latency.
You can do the same
Has anyone ever used a TAPR clock block or other frequency synthesizer
to sort the clock drift / timing problems on a regular computer? I'll
probably end up with a used dell or IBM workstation for this purpose.
Recently, I came across a low-cost frequency synthesizer capable of
using a 10mhz
Hi
It's most commonly done with things like a Soekris 45xx series board. You don't
need anything very exotic for the frequency conversion. The jitter in the PC is
way worse than what the external chips will be creating.
The real question is - what is the magic frequency on the particular
Droid Razr 4G LTE wireless tracker.
-Original Message-
From: Sarah White kuze...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Fri, 30 Nov 2012 3:55 PM
Subject: [time-nuts] Using a frequency synthesizer replacement for motherboard
oscillator
It all depends on what clock your talking about. Any given PC probably has more
than one oscillator onboard.
Generally there will be one for the CPU, one for the display circuitry, and
probably one for the real time clock.
Presuming you are talking about the CPU clock, it should be fairly
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in incredibly small
packages now instead of the old tuning fork-in-a-can ones. peeling off the
load caps and crystal from the board would allow you plenty of spaces to
tack
On 11/30/2012 6:30 PM, Eric Garner wrote:
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in incredibly small
packages now instead of the old tuning fork-in-a-can ones. peeling off the
load caps and crystal from the
I've never done it using to the RTC crystal, but I do it quite frequently
in my Day Job to Ethernet controllers on those same pc mother boards.
-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White kuze...@gmail.com wrote:
On 11/30/2012 6:30 PM, Eric Garner wrote:
the actual RTC on modern
Hi
In the case of the Soekris, it was not the real time clock that we all played
with. THe clock you fiddle is the CPU clock. The system is running FreeBSD or
Lunix, so it's a cut above a typical embedded system. A RTOS (like Windows CE)
will indeed do a bit better with a good CPU clock.
In this case, you're not looking for the RTC but rather the clock that drives
the COU, which is what drives the system clock. On most systems, the RTC is
read only at startup and is not used once the system is running.
John
On Nov 30, 2012, at 6:30 PM, Eric Garner garn...@gmail.com wrote:
On Nov 30, 2012, at 7:10 PM, Sarah White kuze...@gmail.com wrote:
On 11/30/2012 6:30 PM, Eric Garner wrote:
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in incredibly small
packages now instead of the old tuning
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR j...@febo.com wrote:
In this case, you're not looking for the RTC but rather the clock that drives
the COU
Read CPU. Stupid iPad keyboard.
___
time-nuts mailing list -- time-nuts@febo.com
To
OK, I'll bite. Why?
Jim
I've never done it using to the RTC crystal, but I do it quite
frequently in my Day Job to Ethernet controllers on those same pc mother
boards.
-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White kuze...@gmail.com wrote:
On 11/30/2012 6:30 PM, Eric Garner wrote:
On 11/30/12 4:58 PM, John Ackermann N8UR wrote:
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR j...@febo.com wrote:
In this case, you're not looking for the RTC but rather the clock that drives
the COU
Read CPU. Stupid iPad keyboard.
I was wondering.. Clock Oscillator Unit? Cryptic
On 11/30/2012 7:54 PM, John Ackermann N8UR wrote:
On Nov 30, 2012, at 7:10 PM, Sarah White kuze...@gmail.com wrote:
On 11/30/2012 6:30 PM, Eric Garner wrote:
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in
On Fri, Nov 30, 2012 at 04:24:38PM -0600, shali...@gmail.com wrote:
I am not sure that a precision clock will help if the cpu is busy and skips
clock cycles. I believe this is one of the problems with general purpose OSes
like Windows.
I believe the better boards like the Soekis use
Hi
The problem just the clock it's also the operating system. If it's not designed
with timing in mind (= it's an RTOS at some level) then you will have sloppy
timing. Counters can help, but they are not the entire solution. If your email
(or anti-virus or ...) program can pop up and
On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
Hi
The problem just the clock it's also the operating system. If it's not
designed with timing in mind (= it's an RTOS at some level) then you
will have sloppy timing. Counters can help, but they are not the entire
solution. If your
On Fri, Nov 30, 2012 at 8:39 PM, David I. Emery d...@dieconsulting.comwrote:
On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
Hi
The problem just the clock it's also the operating system. If it's not
designed with timing in mind (= it's an RTOS at some level) then you
will
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