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However, we are planning on making some of the functionality work on the PC as an "unsupported" bonus feature. Splitscreen was always something we only wanted to officially support on the x360 due to the controller issues. Valve designer Yahn Bernier has answered the question in a post on the Steam forums: However, after the most recent patch to the demo quietly removed splitscreen support, those same gamers were left wondering whether the "feature" would make it into the final release of the game. Gamers were pleasantly surprised to find that support for PC splitscreen play was available in the demo of Valve's Left 4 Dead by way of a simple console command.
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