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.)









FILENAME: LINLENTH.HLP

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

paragraph.




YOUR TNC

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

word.




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

IL ...






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.





TRANSPORT

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

information down.




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.





PBBS EDITORS

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

back.





SOLUTIONS

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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