

			BIMODEM QUICK START SUGGESTIONS
				by Duane Paulson

	This article contains suggestions for getting up and running
	with Bimodem. It is not intended to be used as a substitute
	for reading the Bimodem manual, but to be used to help get
	Bimodem up and running quickly. Users wishing to fine tune
	Bimodem and implement advanced features will have to read the
	Bimodem documentation. No statement(s) in this article should
	be construed as recommending for, or against, any product.

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WHAT IS BIMODEM?

Bimodem is a file transfer protocol that allows the transfer of files in both
directions at the same time. To date, Bimodem is the only protocol that
allows this. Using Bimodem, I have gotten better transfer rates at
V.32/9600bps than I have with Zmodem at HST/14,400bps.

IS BIMODEM RIGHT FOR YOU?

You can get a perspective on whether Bimodem will give you good results by
answering the following two questions:

	Is the top speed on your modem 2400bps or less?

If it is, then chances are that you can use Bimodem to good advantage.
If you have a faster modem, you need to answer one more question:

	Do you have plain V.32 capability? (Not V.32bis)

V.32 is a full duplex, symmetrical protocol. This means that you can transfer
data at 9600bps in both directions simultaneously. V.32bis is an asymmetrical
protocol, allowing a data flow in one direction of 14,400bps, and only
allowing a flow of 450bps in the other. The HST protocol works the same way.
According to the Dual Standard manual, HST operates in asymmetrical mode at
any speed of 4800bps or higher (page G-5 of the 1988 HST manual). Since
Bimodem transfers data in both directions simultaneously, the effects of
having one side of the link operate at only 450bps can be disastrous. So,
unless you can hook up in plain V.32 mode, you might be able to achieve
better results by using another transfer protocol. If you have a V.32 modem,
though, Bimodem may be for you.

Things that may cause problems with Bimodem:
	Asymmetrical high-speed protocols, including:
		HST protocols (any).
		V.32bis protocol.
	MNP 5 'dumb' data compression.
	XON/XOFF flow control.

Things that are okay with Bimodem:
	300, 1200, or 2400bps modems.
	V.32 protocol high speed modems.
	MNP 1 - 4 error correction.
	LAPM error correction.
	V.42bis 'smart' data compression.
	CTS/RTS flow control.

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INSTALLING AND CONFIGURING BIMODEM

Installation can best be accomplished by running the BINSTALL program.

Configure Bimodem with BICONFIG. I am assuming that you have either a V.32
modem, or a 2400bps or slower modem. Enter '9600' (or '300', '1200', or
'2400') in the space for "Baud rate to base estimates on."

Enter 'F' in the space that asks for "Modem type." Do this even if you have
a Dual Standard, because you will be using it in V.32 mode with Bimodem.
Make sure that you make the connection in V.32 mode.

If your modem supports CTS/RTS flow control, set that option to "Yes."
Consult your modem's documentation for instructions on how to enable CTS/RTS.

Complete the rest of the configuration to reflect your system setup.


KEEPING IT SIMPLE

The easiest way to invoke Bimodem is to run it from BIMENU.

Since Bimodem is a batch protocol, like Zmodem, you don't have to pass any
filenames to it. Unlike Zmodem, Bimodem has a configuration file, so you
don't have to pass any command line parameters to tell it where to find your
modem, or what the speed is. And, since Bimodem transfers both ways at the
same time, you don't have to tell it if you want to upload or download.
Bimodem is always ready to do either, or both!

So, assuming that your Bimodem files are in subdirectory \BIMODEM, your
Bimodem batch file is a simple one:

		\bimodem\bimenu

That's it! You can safely leave the parameter juggling and fine tuning for
later. This one line batch file will get you up and running. Name the batch
file BIUP.BAT and store it with your communications program. Now type
'copy biup.bat bidown.bat' and you will have two copies of the same file.
Start your communications program, and assign the batch files to the
appropriate menus. When (and if) you decide to start fine tuning, you will
already have your upload and download copies in place.

You can pass parameters to Bimodem by running Bimodem directly, but running
it from BIMENU works very well. Just select 'Remote Bimodem' from the
menu to start the transfer. Pressing 'R' is even faster. This is a hot key
and takes immediate effect.

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THE MOST IMPORTANT THING

How well you implement this next suggestion may well determine whether Bimodem
works great for you, or drives you crazy. Bimodem does uploads from a list.
There are several ways of loading filenames into this list. Running BIMENU is
one of them. The thing is, this list stays on your system. If you run Bimodem
once and upload files, and then decide to run Bimodem again without deleting
this list, Bimodem will try to upload these files all over again. Even if you
have deleted the files to be uploaded, Bimodem will waste time trying to
locate these files.

The way to deal with this is to delete the file list before running Bimodem.
This is one of those little details that can drive you nuts if you forget it,
and find yourself uploading something you had no intention of uploading, when
all you were trying to do is download.

You can easily delete the upload list from BIMENU. Just select 'Kill Transfer
List' from the menu and the list will be deleted. Pressing 'K' is even faster.
It takes immediate effect. What you will have to do is train yourself to think
"do I need to delete my upload list?" before hitting 'R' to start the
transfer.

You will notice that I've said nothing about a download list. Bimodem provides
for one. In fact, it's the same list that holds the uploads. My advice is to
forget about it for now. Look at it this way: You know in advance what files
you are going to want to upload to the BBS. You can run BIMENU before logging
on (Just select 'Exit' from BIMENU to quit without starting a transfer).
Downloads are another matter. You may decide to do a new files scan while you
are online, and come up with something you want to download immediately.
For now, just start your downloads the regular way, by typing "db filename
[filename...]" at the main board prompt. Then, select Bimodem, and when the
transfer starts, you're transferring both ways at once. After the transfer is
over, you will be prompted for your descriptions of the uploaded files. I know
that by doing it this way, you won't have the convenience of picking from
lists that you will have using the advanced Bimodem features, but this will
get you up and running in a way that is consistent with the other transfer
protocols that you have been using. You'll have plenty of time for
optimization once you got the basics down.


IN CONCLUSION

The important thing, as always, is to have fun. Relax and enjoy what you're
doing. BBSing should be, above all, an enjoyable hobby. Everything else is
icing on the cake.

All the best.                           -- Duane

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