If you are interested in electronics and haven’t heard of this class, where have you been? This class is a great introduction to how digital electronics works and for the first time (as far as I know) they’ve opened it up to the public online. It is free to audit the course and they just started March 14th, so it is still Week 1! Here’s the introduction video for the class which gives a great overview of it.
So why is this class so great? Well it starts off with a single piece of electronic digital logic, think of it as a 2×1 lego piece. Then you use connect some of these together to build other more functional lego bricks, like a 2×2 brick, then a 2×4 brick, etc. Eventually you end up building your own Central Processing Unit (CPU), then you learn to code it in Assembly language (the lowest human-readable programming language), then you build up to eventually a full blown computer with keyboard and monitor connections that you can write video games like pong, tetris and slightly more complicated things. That’s about as close to starting from scratch as you can get. The real name of it is “the Elements Of Computer Systems” but everyone called it “From NAND to Tetris in 12 easy steps”. NAND is the type of digital logic gate that you start with.
I know it sounds super hard, but it isn’t!
This class is so well laid out that you can do it in your spare time.
The first half of the book is on their website for free, but you can buy the book for about $30. That’s one of the cheapest textbooks I know of, and it is a really good book to have for reference. The Massively Open Online Course (MOOC) is free to audit, but if you want an official Coursera certificate showing you took it, it’s only $50 or so. Some workplaces let you use that for Professional Development credit. This is some of the most fun PD credit I know of. If you aren’t familiar with MOOCs or Coursera, imagine hundreds or even thousands of people all around the world watching videos that are released about once a week with a lecture and homework assignment. Everyone can communicate in an online forum to help each other out. You can even get your work graded (in some classes). Many courses are free, some you have to pay for. Coursera is one of many places offering these kinds of classes. Heck, MIT and other universities have been posting their courses online for free for years now. MIT will let you earn a fancy certificate too (for a cost).
My tips: I used Logisim to build circuit and simulate the logic gates, but you don’t have to. All the software you need is available for free on the class webpage. If you are familiar with FPGA devices, you can build this computer for reals on a cheap FPGA development board like this guy. Either a Xilinx board with Vivado to build and simulate or Altera boards (<– warning, I’ve never used this one before) using Quartas software to design and simulate it should work. This little CPU isn’t super complicated. I warn that actually building it on one of these boards is no easy task, you’ll have to design stuff that is not covered in the class to get it to work with your particular board.