Setting up a 3 or 4 player game

The following section should provide you with enough information to setup a three or four player direct connection "network" game.
However Blizzard Entertainment will not provide any technical support on direct connect networking!

A direct connect network is composed of three or four PCs connected in daisy-chain style by null modem serial cables, as shown below.




The PCs that are in the middle of the chain are "routing" machines, i.e. they relay information to the machine on either side of them. In a two-player game there are no routing machines, in a three-player game there is one routing machine, and in a full four-player game there are two routing machines. A non-routing machine is one that is located at the end of the chain and is directly connected to only one other PC. It is configured just as if it were connected to one PC for a standard two-player game.




The routing machines must have two serial cables connected, one for the machine on either side. This means that you must have two unused serial ports for every machine that will act as a routing machine. Machines that use a serial mouse will probably not be able to act as routing machines, and should be placed at the end of the chain.

The PC serial communications architecture was designed around the assumption that you would only need to have two serial devices at the same time. The PC can communicate with up to four devices, but it shares two interrupt requests among the four devices. Specifically, COM1 shares an interrupt (IRQ) with COM3, and COM2 shares an interrupt with COM4. A COM port is simply a name that your PC gives to a serial device so that the software can communicate with it. In order for direct connect to work properly, you must ensure that there are no active serial devices using the same IRQ request as a direct connect serial cable.

COM Port	Interrupt (IRQ)	Address (I/O)
1	4	3F8
2	3	2F8
3	4	3E8
4	3	2E8

If you find yourself in the situation of IRQ sharing between COM ports, you need to resolve the conflict so that no IRQ is shared. This can be accomplished by making the appropriate changes to the modem, serial devices, and BIOS settings through jumpers or other means as well. Please refer to finding possible conflicts between COM ports. If you still run into problem contact your computer and/or modem manufacturer.

Click here for some common configurations and explanations of the changes necessary to play over direct connect. Remember that the goal is to make sure that no two devices that share an interrupt are in use at the same time!

Once you have verified that all machines are properly connected and have no IRQ conflicts, you can setup the game. Pick a machine to be the "host" machine, preferably a router.

On the machine that will create the game:

• Start Starcraft
• Select "Multi Player"
• Select your Character
• Select "Direct Cable Connection"
• Select "Create Game"

On each machine that will join the game:

• Start Starcraft
• Select "Multi Player"
• Select your Profile
• Wait for a the game creator to finish setting up the game.
• Select "Direct Cable Connection"
• Select the game you want to join

It is important that each machine wait for its neighbor before attempting to join the game. For example, imagine a direct connect network with four players, numbered left to right 1, 2, 3, and 4. Player 3 is the host, and selects Create Game. As soon as the game is created, players 2 and 4 can select Direct Cable Connection. When player 2 has connected, player 1 can join. Any machine can be the host machine, but a host at the end will involve a slightly longer setup time since one more player will have to wait to join.

If the game has already been created when you select "Direct Cable Connection" you will immediately join the game in progress. If the game has not yet been created, select "Retry Connection" after the game has been created.