Re: ALU issue with built in Not chip

Posted by WBahn on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/ALU-issue-with-built-in-Not-chip-tp4035745p4035746.html

What is the value of zx during this test?

If it is a 1, then your first Mux is choosing the 'b; input, which is all '0', and the Not16 is then making this all '1', which is the representation for -1. If x is set to all zeros, then it doesn't matter what zx is because if x is selected, then you have the exact same situation.