Re: ALU Struggle

Posted by bwspot on Apr 19, 2014; 3:29pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/ALU-Struggle-tp4028020p4028024.html

cadet1620 wrote

This worksheet by ybakos may be helpful.

Also, this test I wrote that only tests the computation part of the ALU so that you don't need to worry about the status outputs until after you get the computation part working.

--Mark

So i looked at the worksheet and i am not sure what should i see there.  It proves that simple operations can yield the results, but it does not help me with starting implementing the ALU.  I must be blind but I don't see it yet.  My though process is just to do what the table shows or the worksheet.
Based on the input bits zero or not zero x,y ,  negate or not negate x,y , then or or and x,y , then not out or leave it alone.  I feel like i need to use dmux to start with above,  but still cannot see the whole picture.

Edit:I am trying to start making the table work piece by piece with the smallest elements i can and then i will try to combine it.  I start seeing that i might not need any dmuxes but simple or and and.