PACKET RADIO: Line Lengths
Steve Wolf, W8IZ@W8IZ.#NEOH.OH.USA.NA
(This text from the W8IZ packet radio bulletin
board. It's formatted to fit a 80 character screen.)
From: Steve, NO8M@NO8M.OH.USA.NA
Date: January 15, 1990
Subject: Keeping Line Lengths Less Than 80 Characters
There are a number of reasons you want to keep the lengths of your lines
less than 80 characters. This file will explain why you need to do this.
Depending on your computer, you may see 80, 60 or even less characters
on your screen. This is not the line length. A line ends in a carriage
return (where you hit the ENTER key). If you only have carriage returns at
the end of your paragraphs, then your line length is the length of the
Your TNC will affect how your message looks after it is uploaded. When
you send information to your TNC, a circuit in the unit will format it into
packets to be sent over the air. It will use the value set in the PACLEN
command to break the information up. PACLEN is the maximum number of
characters per packet.
If the TNC encounters a carriage return prior to getting to the number
of characters in PACLEN, it knows to stop and send the packet. If you send a
very long line, one with more characters than the value that is in PACLEN, the
TNC will do the sending for you.
Lets say your PACLEN value is 255 characters. You send a very long
paragraph with a carriage return only at the end. Let's say the paragraph
contains 1000 characters. Your TNC will accept 255 characters, stop, add a
carriage return and send the packet. This carriage return is added regardless
of what is at the 255th character. It may be added right in the middle of a
This is the reason you see so many bulletins that look all broken up.
Here is an example of a message sent with a TNC PACLEN of 49. The
operator sent lines much longer:
THE YACKAMONGA HAM RADIO CLUB WISHES TO ANNOUNCE TH
AT WE ARE HAVING OUR THREE HUNDRETH QUADANNUAL HAMF
EST IN THE GREAT STATE OF YACKA.
YACKAMONGA IS EASY TO GET TO. TAKE INTERSTATE 322S
TO EXIT 435. TURN RIGHT, TURN LEFT, THEN RIGHT UNT
You can not get around this problem by setting you PACLEN less than 80
characters. The TNC will just break the lines up willy-nilly and you will get
all sorts of weird looking lines.
You need to enter a carriage return before the value you set in PACLEN.
As you will see, use a carriage return before the 80th character.
If your screen does not show an 80 character line, there is no problem
sending messages formatted with smaller line lengths. A good example is with
the Tandy TRS-80 Model 100 laptop. It has a screen length of 40 characters.
You might see a message like this from a Model 100:
The Tandy TRS-80 Model 100 is a nice
computer for both at home and portable
packet use. It is battery powered and
has an RS-232 communications port.
But, there is no storage (at least
no easy storage). There is also a
problem with the 40 character screen.
Many of the 80 column messages will
be hard to read with this screen.
If you use a node to transport your packet to a PBBS, you might get
another surprise. There are additional things in a packet used by nodes to
help the nodes route your packet. Because of this, a node will only accept
236 characters per packet.
If you had sent 255 characters from your TNC, the packet will be sent
out of the node as two packets. One will be 236 characters (plus the routing
information) and the other will be 19 characters. This slows your flow of
There will be no additional carriage returns added to your packet in
this case. It will still look busted up because of the carriage returns added
by your TNC.
Let's say you enter a message into the PBBS but you have made a mistake.
You signed your message in the proper manner, with the full hierarchial return
address, like this: NO8M @ NO8M.OH.USA.NA. But this time, you made a
mistake. You entered your home call wrong, like this: NO8M@NM8O.OH.USA.NA.
In these cases your sysop can edit your message and correct your error.
It is easier than sending the message back to you with a note.
However, the editor on the MSYS PBBS is limited. It will work with only
80 character lines. This is to limit the code that is required for the
editor. A better editor can be installed but it would take space better
suited to PBBS functions.
If your line lengths are over 80 characters, your message would have to
be taken to another program and edited. You are more likely to get it sent
USING A TERMINAL PROGRAM
If you are entering a message from a terminal program, hit a carriage
return (the ENTER key) before you send 80 characters.
USING A WORD PROCESSOR
Many word processors will allow you to enter your message without regard
to line-length. This makes editing, spell checking and other functions
easier. They will then have a special function to allow the file to be saved
in an 80 character per line format.
This file was done in the Word word processor. It was saved with
carriage returns using the "DOS SAVE" function.
It might help if you can set your word processor to show carriage
returns on the screen. Consult your manual.
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