Eclectic

Language, computing, and other topics

Fire Dogs

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The following story is from Lev Tolstoy’s First Russian Reader of 1875. This is my translation. As far as I know it has never before appeared in English.

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Written by David Chappell

January 3rd, 2018 at 4:24 pm

Posted in liturature,russian

Electrical Power and Power Loss

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Basic Electrical Units

A volt is a unit of electrical potential. Electrical potential in turn is the force which a power source (such as a battery) applies to a connected device in order to push electrons through it. Electrical potential (voltage) is comperable to the presure which a pump applies to a plumbing system in order to push water through the pipes.

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Written by David Chappell

March 2nd, 2016 at 4:18 pm

Communicating Clearly About Computing

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Those of use who work in IT are frequently called upon to explain our work to people who are less familiar with computers than we are. It should be our goal to speak and write as clearly as possible. To do that we must avoid jargon, slang and expressions which are easily misunderstood. We should not write to be understood. We should write so as not to be misunderstood.
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Written by David Chappell

January 14th, 2016 at 9:43 pm

Waiting to Bite: BIND and Invalid Zone Files

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It looks like Webmin lets you create DNS entries which BIND 9 does not like. When it sees one it refuses to load the whole zone and keeps what it has in RAM. This may go unnoticed for months until the server is rebooted. BIND then restarts with that zone completely empty!
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Written by David Chappell

January 14th, 2016 at 9:34 pm

Draco’s Policies were Draconian

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Have you every wondered why we call a harsh policy “draconian”? This is one of those words which comes from the name of a famous person.
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Written by David Chappell

January 14th, 2016 at 6:35 pm

Posted in language

Flowroute

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I have been grieving ever since Voicepulse canceled its flexrate program and been looking for a new low-price provider with good quality.
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Written by David Chappell

July 15th, 2010 at 3:12 pm

Posted in asterisk,voip

Reducing Echo in Telephone Handsets

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A common source of echo in VoIP phone systems is the telephone handsets. Of course, non-VoIP phone systems have this source of echo too, but it often is not so evident because without the buffering the echo delay is not as long.

Old Bell 500 series telephones have a wad of cotton wool in the handset to prevent sound from traveling from the receiver, through the hollow handset body, to the transmitter. But, many modern telephone handsets lack this important component. Here I show how I added cotton wool to the handset of a Linksys SPA-841 in order to reduce echo.
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Written by David Chappell

January 22nd, 2009 at 5:19 pm

Posted in telephony,voip

How to be a Good VoIP Provider for Asterisk Users

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There is more to being a good VoIP telephony provider for Asterisk users than simply offering the best balance of price and reliability. Usability is also very important. Here are some things which make for a service more convenient for Asterisk users.
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Written by David Chappell

January 9th, 2009 at 10:13 pm

Posted in asterisk,telephony,voip

Is open source telephony a serious option?

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I was recently asked whether anyone would every really consider replacing a tired old PBX with an open source system and whether we had any experience with Asterisk. Here is the answer I wrote, based on our experience here at Trinity College.
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Written by David Chappell

June 10th, 2008 at 3:56 pm

Join the DUNDi cloud, call Europe!

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Do you have an Asterisk box and an underutilized T1? Or do you have a large number of DID numbers on your PBX? Why not join a DUNDi cloud and trade access to your numbers or to your local calling area for access to other organizations’ numbers and local calling areas?
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Written by David Chappell

May 1st, 2008 at 5:19 pm