a place I put stuff

nand2tetris: low-level love

Posted on August 7, 2013

I’ve been working through The Elements of Computing Systems, or as it is sometimes called nand2tetris. This is a fun course where you start out by being given (say: from God) the humble nand gate (file photo below):

Schematic of a nand gate

And here’s a nude photo (showing how one would be implemented):

Electrical schematic of a nand gate

But as far as nand2tetris is concerned, you can just assume that the above is a fact of life. You have a nand tree. So what do you do? well you start on an adventure where you define Not then And then Nor and, well you get the idea. Soon you find that you have a working ALU.

I’m currently on the cusp of making the hardware to software jump. All along I’ve been having a blast wiring up these little beasties in HDL

The course finishes up with implementing cool software in a HLL language. I haven’t peeped this far ahead but it is supposed to be akin to Java. Oh yeah, by the time you get to this point you’ll have implemented the compiler for this language, the VM that it runs in, the raw machine code the VM is written in, the CPU that runs that machine code, and so on. It goes all the way back to that humble nand gate that you started out with.

I hope to post some updates as I progress through the course, but the quickest way is to check my commits over on my n2t github project.

Edit: sorry to say this, but I’ve taken down that repo since it conflicts with the wishes of the authors of the course.

As a slight digression, but surely belonging here, this has been something of a summer-o-hardware for me. I started reading CODE by Charles Petzold a while back and the bottom-up description of computing that he laid out was intoxicating. I had to learn more and get my hands dirty with bits and bytes. And that’s when my hardware voyage began.

In keeping with this theme, here’s a short reading list if you want to blast your brain with computing. In fact, I bet that if you were to go through all these books it’d be like getting a degree in computer science – with a minor in cool-nerd history:

There you have it. Go off and hack hardware!