Done with ALU...

[JustinM]

Wow, after working on this for about 30 minutes a day for a couple of weeks... I finally have a working ALU... I feel like breaking out the champagne over here...

Oddly enough, ZR and NG took me a while to figure out. Did you guys handle ZR with 4 parts, involving using the output of 2 Or8Way parts?

Persistence pays off. I've noticed that there are less forum posts in each corresponding chapter here. I hope I can finish this...

[cadet1620]

Yes, that's the most direct way to generate the zr flag.

We'll be here to support you as you journey through the remainder of the book.

--Mark

[JustinM]

Thanks! How long did it take you to do TECs, if I may ask?

[cadet1620]

I'm not a good datapoint for typical. I'm an embedded systems / firmware engineer with 35 years in industry and a part-time math teacher. I found Nand2Tetris when I was looking for online resources for an ex-student of mine. To get a feel for the course before recommending it I read chapters 1-3 and did the projects in a couple of evenings. Finished through chapter 6 is a week or so of evenings. Although my student never went beyond chapter 2, I was hooked. I ordered the book and did the remaining chapters in evenings over 3 or 4 weeks after it arrived.

--Mark

[ybakos]

It took me many weeks. Part of the time estimate depends on how addicted/consumed/troubled you become by the projects.

[JustinM]

Thank you for the responses. Yes, I find that I really progress once I feel I'm close to the answer, or have an "aha!" moment- I get pulled in and end up spending more time on the project than intended.

[vishparshav1]

Well i used a modified compartor for ng flag, compared on the 16th bit and for zr flag i used a normal 16 bit comparator with second 16 bit as all zeroes.

[manu]

Though I started just a few days ago, completed all hardware sections thanks to the help from the forum, especially from Mark. Not that I have a lot of free time but got so hooked that, after daytime job, I ended up spending all my last few evenings in front of the computer. Going to start chapter 4 now.

[ismithers]

I must say finishing the ALU was quite satisfying. I'm now on to chapter 3, I'm really looking forward to the later chapters when it talks about machine code and the like! :)

[wyleEcoyote]

I just wanted to say I just finished the ALU and can not explain the pure joy I felt when i saw the "Comparison ended successfully"!  I think I held my breath through the entire test :)

The ZR and NG definitely took some time, but it feels great to have a working ALU.  I'm really enjoying this book.  This forum is a great compliment to it.

On to Chapter 3!