Error in my ALU

Posted by Mosey on May 03, 2013; 7:24am
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Error-in-my-ALU-tp4026768.html

This is my alu. Can you tell me why it gives me an error message "Line 71 operated has no source pin"?

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