Low-level programming is how we write instructions that are super close to how the computer works. It’s not easy, but it gives you more control. In this lesson, we’ll explore a simple tool called the Little Man Computer (LMC) that helps you learn how low-level instructions really work.
Learning Objectives
By the end of this lesson, I will be able to:
Understand how low-level code works.
Write simple programs using LMC instructions.
Explain what the accumulator, memory addresses, and instructions do.
Little Man Computer (LMC) – A model that helps us understand how simple CPUs work.
Accumulator – A special register that holds numbers during calculations.
Instruction – A single command the computer can follow (e.g., INP, ADD, STA).
Memory Address – Where numbers or instructions are stored.
Branching – Making the program jump to a different part based on a condition.
LMC is like a classroom role-play: imagine a tiny person (the "Little Man") in a post office with drawers. He follows your instructions, one step at a time. These instructions include getting numbers, adding them, storing them, or checking if they’re zero.
Why Learn Low-Level Programming?
It helps you understand how computers really think.
It shows you what goes on behind the scenes of Python or Scratch.
It’s great for controlling small devices with limited memory.
Example Program: Add Two Numbers
This program takes two inputs and adds them together. It stores the first number in memory (FIRST), then adds it to the second input and outputs the result.
INP // Get first number
STA FIRST
INP // Get second number
ADD FIRST
OUT // Show result
HLT // Stop
FIRST DAT
Real-World Example
Imagine a vending machine: it needs to check how much money was inserted, add credit, and decide what button was pressed. These small steps are just like LMC instructions!
🚫 Mistake: Forgetting to store or load values correctly. ✅ Tip: Use comments in your LMC to explain what each line does.
If you had to build a simple calculator for a robot using only 5 instructions, what would they be and why?
What does INP do in an LMC program?
What is the accumulator used for?
Why is STA needed before ADD?
How do branching instructions make a program more powerful?
Give a real-life example of a machine that could be programmed with low-level code.