Since many of us are not so old as I am, and aren't familiar with the
PDP-11 family, I should have mentioned that this happened in the middle
80's.
Uno Staver wrote:
We bought a bunch of PDP-11/23s as part of a communications network
system. After successful acceptance tests in Boston, MA,
and frequency measurement
Subject: Re: [time-nuts] 60Hz mains clocking in computers
Since many of us are not so old as I am, and aren't familiar with the
PDP-11 family, I should have mentioned that this happened in the middle
80's.
Uno Staver wrote:
We bought a bunch of PDP-11/23s as part
We bought a bunch of PDP-11/23s as part of a communications network
system. After successful acceptance tests in Boston, MA, the systems
were commissioned in Sweden with 50Hz AC. To make the RSX-11M O/S
time-of-day clock run OK, the developers modified some piece of code.
Uno Staver
Bill
, but programs ran slower. Hmmm.
Leigh.
At 1:44 AM + 12/13/09, time-nuts-requ...@febo.com wrote:
Date: Sat, 12 Dec 2009 17:29:17 -0800
From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu
Subject: [time-nuts] 60Hz mains clocking in computers
To: time-nuts@febo.com
Message-ID: 3058527a-cc99
On Sun, Dec 13, 2009 at 07:39:05AM +, Poul-Henning Kamp wrote:
In message 2157.12.6.201.67.1260689371.squir...@popaccts.quik.com, J.
Forste
r writes:
I'm not so sure about the Nova 1200. I think all the Novas had the RTC was
on a standard I/O board, [...]
No, it was an option, but
At 1:44 AM + 12/13/09, time-nuts-requ...@febo.com wrote:
Date: Sat, 12 Dec 2009 17:29:17 -0800
From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu
Subject: [time-nuts] 60Hz mains clocking in computers
To: time-nuts@febo.com
Message-ID: 3058527a-cc99-4174-be75-21dd92334
Joe Gwinn wrote:
At 1:44 AM + 12/13/09, time-nuts-requ...@febo.com wrote:
Date: Sat, 12 Dec 2009 17:29:17 -0800
From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu
Subject: [time-nuts] 60Hz mains clocking in computers
To: time-nuts@febo.com
Message-ID: 3058527a-cc99-4174-be75-21dd92334
In message 4b251964.5040...@rubidium.dyndns.org, Magnus Danielson writes:
Joe Gwinn wrote:
The exception to this was that video generators were (and still
are) often locked to the AC line so that hum bars would not drift across
the screen.
I have never seen this in any of the devices I've
Poul-Henning Kamp wrote:
In message 4b251964.5040...@rubidium.dyndns.org, Magnus Danielson writes:
Joe Gwinn wrote:
The exception to this was that video generators were (and still
are) often locked to the AC line so that hum bars would not drift across
the screen.
I have never seen this in
Industrial process control requires that event time stamps be close to
the correct social (wall clock) time, for correlation with events that
were not digitized. Computers at the heart of these control systems
were required to run on DC from batteries, and so the real-time clock
was derived from a
On 12/13/09 7:52 AM, Joe Gwinn joegw...@comcast.net wrote:
At 1:44 AM + 12/13/09, time-nuts-requ...@febo.com wrote:
Date: Sat, 12 Dec 2009 17:29:17 -0800
From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu
Subject: [time-nuts] 60Hz mains clocking in computers
To: time-nuts
Dear Jim,
Another overlap in our past. Back when I was at UCLA I helped the
Ethnomusicology dept with their filming along with synced sound. This was in
1963-64. I designed and built a crystal sync system using the newly available
RTL logic ICs. I then modified a 16mm Arri to use it to
At 4:53 PM + 12/13/09, time-nuts-requ...@febo.com wrote:
Date: Sun, 13 Dec 2009 17:42:12 +0100
From: Magnus Danielson mag...@rubidium.dyndns.org
Subject: Re: [time-nuts] 60Hz mains clocking in computers
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
I'm trying to get to the bottom of whether or not any computing
equipment made around the advent of UNIX systems (or any time-slicing
system) used the mains cycles of 60Hz as phase lock for the internal
system clock. My guess is that perhaps they did not as the computing
logic is DC
On 12/12/09 5:29 PM, Colby Gutierrez-Kraybill co...@astro.berkeley.edu
wrote:
I'm trying to get to the bottom of whether or not any computing
equipment made around the advent of UNIX systems (or any time-slicing
system) used the mains cycles of 60Hz as phase lock for the internal
based on the mains.
Stanley
- Original Message
From: Colby Gutierrez-Kraybill co...@astro.berkeley.edu
To: time-nuts@febo.com
Sent: Sat, December 12, 2009 7:29:17 PM
Subject: [time-nuts] 60Hz mains clocking in computers
I'm trying to get to the bottom of whether or not any computing
co...@astro.berkeley.edu said:
I'm trying to get to the bottom of whether or not any computing
equipment made around the advent of UNIX systems (or any time-slicing
system) used the mains cycles of 60Hz as phase lock for the internal
system clock.
The IBM 360s bumped a memory location each
Talk about dusting of the old brain cells.
I seem to remember that the PDP 11/23s did indeed allow the use of the 60 hz
as an interrupt for precision timing if that can actually be said. The data
general nova 1200 also. Boy thats exposing ones age.
On Sat, Dec 12, 2009 at 8:29 PM, Colby
Yes, the whole PDP-11 line used line frequency to update the real-time
clock.
DEC had a real-time operating system, very useful for emulation of analog
process control functions. Of course, an RTOS is more than just the clock.
We lost that anchor to real time in the interval between the PDP-11
In message 3058527a-cc99-4174-be75-21dd92334...@astro.berkeley.edu, Colby Gut
ierrez-Kraybill writes:
I'm trying to get to the bottom of whether or not any computing
equipment made around the advent of UNIX systems (or any time-slicing
system) used the mains cycles of 60Hz as phase lock for
I'm not so sure about the Nova 1200. I think all the Novas had the RTC was
on a standard I/O board, along with the serial interface, PTR, PTP. I
remember two crystals, one 16.000 KHz for the clock. The other was for the
Baud Rate generator, somewhere about 1 MHz. A minimal system had 3 cards
(CPU,
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