How to make an ALU (Arithmetic Logic Unit) from logic gates and mux | nand2tetris project 02

[@raagamparmar179]

This is amazing, than you very much!

[@吳述宇]

Hi! I have a question which is that if I change the selectors' sequence in the Mux4way16 in the beginning, it will not output the final input of x and y successfully. Why?

[@onthelearn]

Hi! It is how the Mux4way16 was specified to work by the nand2tetris project creator. If you take a look at the description of the mux in Mux4Way16.hdl file of project 01, it describes how the mux should work with selector signals so we designed it that way. There is a video (5th on the nand2tetris playlist) that may give you a better picture. Ofcourse you can change the sequence of selector signals, but then you also have to modify the truth table and therefore the input sequence so that the selectors select the correct input signal as output. Hope it helps. and I'm sorry if I misunderstood the question.

[@吳述宇]

@@onthelearn Thank you! I solved where I am confused about!

[@kishernravindren1409]

At 1:49 why is Nx on the left hand side of the truth table and not Zx?

[@orelfichman779]

oh man this course is so over my mental capacity