Re: Eval button keeps being disabled

Posted by Albert G on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Eval-button-keeps-being-disabled-tp4025192p4025769.html

There are two other points I noticed about this:

1) Right after loading a chip, the EVAL button is always disabled. The chip actually runs on the default input for all pins, i.e. all zeros. The EVAL button only gets enabled if you change any of the inputs to a different value.

2) If the chip produces no output at all, then also the EVAL button is disabled. A chip without output ? That makes no sense, will you say. I was actually building up the ALU and wanted to do debugging on the partially built chip. But I noticed I was unable to test anything since the EVAL button never got activated. So I just added a default output to one of the output pins and I was able to do my debugging.

Albert