Merry Christmas, everyone! Between juggling a full-time job as a data scientist and pursuing my computer science graduate degree part-time, I didn’t think I’d have much bandwidth for extracurricular projects. But when the holidays rolled around, I found myself itching to step away from data engineering and machine learning modeling—and dive headfirst into the world of low-level programming. Surprising? Maybe. But it’s been a thrilling journey so far.
Stepping Out of the AI/ML Bubble
I love AI/ML. But one thing I’ve realized is that constantly working at a high level (think PyTorch, scikit-learn, XGBoost, etc.) can sometimes obscure what’s really happening under the hood. Sure, I can engineer data, develop models, and conduct data experiments all day long. But when something breaks at a deep level—like in a CUDA kernel, or even just the memory management within my Python environment—I’m reminded there’s a whole world of “lower-level” knowledge I’ve yet to fully explore.
The Rust Detour That Led Me Here
Before deciding on C and LC-3, I spent good months early this year experimenting with Rust. Rust’s take on memory safety, ownership, and borrowing gave me fresh insights into how resources are managed under the hood. It was honestly a game-changer for my perspective on systems languages, especially around preventing common pitfalls like null pointers and data races.
Yet, while Rust’s abstractions are powerful, I still felt a pull toward diving even deeper into “raw” territory. I wanted to confront memory management head-on (hello, malloc and free!) and learn about the hardware from a more fundamental standpoint. So, in true holiday fashion, I rolled up my sleeves, turned my attention to C, and zeroed in on a minimal teaching architecture: the LC-3.
Why LC-3?
The LC-3 (Little Computer 3) is a teaching architecture designed to introduce beginning learners to the essentials of computer organization. It’s simpler than x86 or ARM but still incorporates the core concepts—registers, memory, instructions, and the ALU. You see how a machine fetches and executes instructions, and how data travels through the CPU pipeline.
For someone new to this world (like me), LC-3 hits the sweet spot: small enough to grasp, yet detailed enough to illustrate the crucial architectural principles that make modern computers tick. Plus, there’s something undeniably satisfying about working with a “mini” assembly language that you can wrap your head around in a relatively short time.
The Holiday Project: Building an LC-3 Assembler in C
With some rare downtime over the holidays, I decided to tackle a toy project: implementing an LC-3 assembler in C. It might sound daunting, but that’s precisely what makes it fun. Coding in C forces me to sharpen my skills at a lower level—manually managing memory, fiddling with pointers, and generally operating without the safety nets provided by higher-level languages.
What is this assembler supposed to do?
- Parse LC-3 assembly instructions from a text file
- Convert these instructions into their respective machine code
- Output a binary or hexadecimal file that I can (eventually) load into an LC-3 simulator
The process is simultaneously methodical and creative. I’m breaking down each instruction type (ADD, AND, NOT, etc.) into opcodes, handling operands, managing labels, and dealing with corner cases (like immediate values that might overflow). Every step has been an education—whether it’s about string tokenization in C or learning exactly how branching instructions update the program counter in LC-3.
What I’ve Gained So Far
-
A Deeper Appreciation for Abstraction: Exploring Rust already taught me the value of memory safety and high-level abstractions, but writing my own assembler in C has offered a whole new perspective. Now I see firsthand how much work goes into making higher-level languages feel effortless.
-
Sharper Debugging Skills: Chasing down memory leaks in C or debugging a mislabeled branch instruction in LC-3 is entirely different from debugging Python scripts or dealing with Rust’s borrow checker. It’s upgraded my overall debugging game in ways I didn’t expect.
-
Fresh Perspectives for AI/ML: Understanding memory layout, CPU operations, and data flow at a low level helps me better appreciate the hardware behind large-model training. There are performance optimizations and edge cases in AI that only become clearer once you peek under the hood.
Looking Ahead
My LC-3 assembler is very much a work in progress, but I’m already envisioning a day when it can run basic LC-3 programs that I’ll share on GitHub. More immediately, I plan to post a series of in-depth blog articles on my implementation journey—ranging from parsing assembly tokens to handling thorny edge cases. If that interests you, keep an eye on this space for more updates.
In the meantime, I’m excited to see how this new knowledge will feed back into my AI/ML world. Balancing full-time data science work and part-time graduate studies can be hectic, but exploring the fundamentals of computing has felt like building a stronger scaffolding for everything that sits on top. And that, to me, is the perfect holiday present.
So, if you’re an AI/ML person who wants to step out of your comfort zone—or even if you’ve dabbled in Rust and crave a deeper look under the hood—why not give C and computer architecture a try? You might just discover a new passion (or at least a fresh perspective) on how the magic happens behind the scenes.
Happy learning, happy holidays, and stay tuned for more LC-3 adventures!