[GreenKeys] M32 Answer back coding...

[Henning Treumann]

>From international ITU recommendation it is not needed to put
a CR LF at the end also, but very important is it to
put it AT THE BEGINNING ! As the called machine's print head
could be "somewhere" left from the last message.

Henning DF3OE




2017-11-15 17:45 GMT+01:00 Kenneth Gartland <trnsrme at gmail.com>:

> Hi all!
>
> Firstly, congrats to our newest i-Telex "Kids"
> on the block, namely Paul & Jack!
>
> It is so encouraging to see new installs
> added to the subscriber base in North America...
>
> Answer back drums are hard to find these
> days, used to see the odd one pop up
> on eBay, but not for a very long time...
>
> The following info, I hope will clarify the
> coding issue for the A/B drums...
>
> There used to be several commercial  coding
> "Standards" employed by various commn's
> carriers, none of which apply to us now...
>
> We used to use the following coding practice
> during the later days of Telex:
>
> Lttrs
> CR
> LF
> (Followed by "Fill" characters [Lttrs] if there are any
> uneeded characters in the message body)
> Message body
> CR
> LF
> Lttrs
>
> The answer back drum can contain up to
> a total of 20 characters, including all
> functions...
>
> Usually, there are about 14 characters to play
> with for the message body...
>
> Tine "Broken out" is a mark, left in, a space...
>
> Holding and looking at the drum with the
> row numbers facing left, the coding count
> from left to right for each row is as follows:
>
> code levels
>
> 1, 2, 3, 4, the 5th bit uses the tine in the 6th position,
> the one in the right hand side of the drum to
> the right of the "Print suppression" tine...
>
> Remember, these drums are also used in M33 units,
> so there are unused tines which are not needed
> for Baudot coding...
>
> In the "ST" row, it is recommended practice
> to remove the tine in the "Print suppression"
> row, this is needed to avoid a false "Blank" being sent
> to line during the ansback start up....
>
> It is also not recommended to "Correct" a coding
> error, by breaking out the PS tine, as again it can
> send a blank, which mite cause a line disconnect!
>
> Any coding errors, hopefully none, are "Fixed"
> by converting the errored character to an
> all marking one (Lttrs)...
>
> This only works if you have one or more "Fill"
> characters to spare, if not, you have to live
> with your​ handiwork...
>
> Here is an old guys coding "Tip"
>
> Write down the entire coding sequence, including
> all functions spaces etc., to a max of 20
> characters...
>
> If you have any extra "Fill" characters, designate
> their coding at the beginning of the coding
> sequence following the Lttrs, CR, LF...
>
> When done, here is the "Tip"...
>
> Code the drum in the "Reverse" order from character
> row 20 to row 1, in other words you will be
> working backards from the end of the sequence
> to the beginning...
>
> By doing this, if you make an error, you can correct
> the mistake with a lttrs, and move on, providing you
> have at least one "Spare" fill character to use...
>
> If you decide to code starting in row 1, and have
> coded all your "Fill" characters, and then make
> a coding error, your done son!
>
> There is no fixing it then!
>
> I wud suggest to anyone, when composing
> your coding sequence to leave at least one
> spare "Fill" character at the beginning to work
> with, just in case!
>
> P.S. Answerback drum, part# 180827, will already
> have the "Print suppression" tine broken out of
> the "ST" row...
>
> If you have a Model 33 drum, part# 184149,
> it will have the tine in place in the ST row,
> and you will have to remove it before proceeding...
>
> That's all for now folks, hope this has clarified
> some of the coding confusion...
>
> Cheers!
>
> Ken
> VE3-HMQ
> i-Telex 61663
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> 2002-to-present greenkeys archive: http://mailman.qth.net/
> pipermail/greenkeys/
> 1998-to-2001 greenkeys archive: http://mailman.qth.net/
> archive/greenkeys/greenkeys.html
> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20171115/bb2a3931/attachment.html>