I've learned more than just low-level computing concepts. Through completing the projects, I've been able to reflect on my problem-solving skills:

• Step back: If you can't solve something, try a different approach. How I remember this: Dig 5 holes, not 1.
• WHAT: Define what you are solving, specifically. Our brains can't hold everything at once. Breaking down a problem to its first principles and stating them nicely in a bullet point list provides your subconscious with all the raw materials it needs to solve the problem.
  • Related Concepts to WHAT
    • "To understand is to know what to do."
    • First Principles - Question by asking "Why?" until you have the most basic truths of the problem, and then you will understand
    • "Asking a question is 85% of the way to understanding the problem"
    • Problem Solving 101: Identify the root cause of the problem
    • Catalogue of Attributes in Music - Identify the instrument, tempo, etc., to break down a song and understand its construction

Writing out the specifics is very important in problem-solving. Often we don't see reality because we're stuck in our thoughts. If you write out the parts of a problem, you can see the truth of the situation. I had realised this before when trying out meditation, that I thought I was focusing on the breath at my nose, but I was actually thinking about focusing on the breath at the nose, rather than the physical sensation. In this course, I realised that I couldn't solve some of the logic gate problems until I wrote out the WHAT - that is, WHAT, SPECIFICALLY, am I required to input/output? And as soon as I defined things, clearly, I knew what to do.

I am reading through CODE by Charles Petzold to understand computers from the atom up to high-level languages. 50 pages of notes and counting...

Projects from the online Nand2Tetris course on Coursera, which builds a computer from first principles. Each folder in the /projects folder tasks you with constructing a family of logic gates, building up to PC components such as an ALU (Arithmetic Logic Unit). For example, in week 00/01, I had to construct an AND gate (being given a NAND to start with), and from there, I was able to build up more complex logic gates such as the OR and XOR. In project 02, I implemented an ALU using the logic gates I had built beforehand.

All the gates/parts are implemented using HDL - Hardware Description Language. Each project is essentially an exercise in problem solving/boolean algebra.

The .hdl files found under /projects (weeks 00-03: logic gates) are openable in the HardwareSimulator file found under the /tools directory. Week 04's projects (Fill/Mult) are opened in the CPUEmulator, which looks like this:

The above image shows the CPUEmulator running my screen filling HACK assembly program. To repeat what you see, open /tools/CPUEmulator. Once the tool is open, click the file icon and load in /projects/04/fill/Fill.asm. Once that file is loaded, select "No animation" and then click the two blue arrows. Press a button, and the screen will fill!