The following message was originally posted on alt.games.marathon to answer the questions that I am asked the most often. It is in the original form form the post, so has not been edited.
Since the initial release of NetLink, I have found that there a are a few
questions that are asked asked all of the time. I'll try to answer them
here and at the same time explain some of the problems people are having
and how to fix the problems.
I'll start with init strings, since this seems to be one of the most
common problem areas. The init string list that comes with NetLink was
based on information from my Global Village Platinum and GV Gold Modems.
This means that all of the init strings are correct for owners of GV
modems and should not require any modification. They also appear to work
with most other brands of modems. The main exception to this rule would be
the modems that are made by USRobotics. None of the init strings that come
with NetLink work with these modems, but with the help of some of the
tester I have now have some init strings to use with USRobotics modems.
With Error correcting: AT&F&A1&B1&M4&H1&R2Q0E0V1X4
Without Error correction: AT&F&A1&B1&M4&H1&R2Q0V1X4
I am currently compiling a list of modem strings for different brands of
modems to provide with the next release.
On the topic of USRobotics modems, a second problem has also been
discovered. These modems only support a very limited number of DTE speeds
and will not respond unless set correctly. If you are using a USR modem,
set the DTE speed to 57.6 since I know this setting works. I'll be sure to
mention this in the docs the next time.
Next, I would like to say a few things about error correction and reliability.
If you have been using NetLink with Marathon, you may find that the game
will sometimes appear to lockup during the game. If this happens, your
computer has not crashed. You can still command-Q and gather another game.
The reason this happens is a network packet was damaged durring
transmission and Marathon never recieved it. It will freeze the game while
it waits for a packet that will never come. The more noise there is on
your phone line, the more often this can happen. I have seen games run for
hours without any problem and I have seen it where the game would not last
for more than a few seconds. I am working on improving the NetLink's error
correction method, so it can recover the game.It's not a matter of not
knowing how to do it, but a matter of finding a way to do it that does not
impact the performance. Marathon has it's own error correcion system, but
it made the game unplayable on a 14.4 modem so NetLink disables it. It's
about twice as fast with the error correction off.
I have found that 28.8 modems are fast enough to use modem level error
correction without causing much loss in performance. 14.4 modems on the
other hand will choke if you try using error correction with Marathon.
Even so, it may be better than having the game freeze every 30 seconds if
you have dirty phone lines. When modem level error correction is used, the
game will freeze like before, but recover after about one second after the
data is resent.
Currently I am looking for a way to perform 100% reliable error correction
without impacting performance.
In a few cases, people have reported that the remote computer does not
show up when they try to gather a game. This happens when one or more of
the computers fail to register it's name on the network. I suspect this
happens because appletalk normally only does this when you first startup
or when you switch network hardware. This is a porblem for NetLink because
it is not likely that you will be connected to someone at either of these
times. I am going to make sure the next release of NetLink forces the
computers to register when they first connect. Until the next version is
ready, I recommend using MacPing, which will force the computers to
register just by launching it. MacPing is also a usefull to to diagnose
AppleTalk and IP networks and can be used to test the performance of
NetLink with different settings. You can get MacPing from
ftp.dartmouth.edu. This problem will be resolved soon, so you will not
need MacPing.
Note: You might want to try making sure both systems have the same version of AppleTalk. This appears to prevent the problem from occuring in the first place.
I have recieved a few quetions about problems with Apple's GeoPort Telecom
Adapter. Like it says in the docs with NetLink, I do not recommend using
this with NetLink if you intend to play games. It is not very fast if
requested to performs lots of small reads and writes as is the case with
games. Because of this, it will either be very slow or not work at all.
You will also find this modem has the same problem with games with built
in modem support. If you want to play games over the modem, get a real
hardware modem. They work much better.
The last common problem is with users of Open Transport, which is Apple's
replacement for classic AppleTalk and MacTCP. Currently it is only on the
new PCI Macs, but there will be a version that works on all Macs shortly.
If you have a PCI mac and have not downloaded the updated version of OT,
you probably have version 1.0.6 which is full of bugs. NetLink does not
work with 1.0.6. You will need to get 1.0.8 to use NetLink. You can pick
this up from http://www.amug.org/~marathon/netlink or from Apple's various
ftp sites. The OT implementation of AppleTalk appears slower than classic
AppleTalk. There will be a new version out soon which should address this
problem.
Well, that covers the vast majority of the questions that I am asked and
the problems that have been reported. If you have a problem that is not
convered here, please E-mail me at NetLinkR@aol.com, I'd be happy to
