How can these simple components be connected to store data, perform calculations, and execute a program? A MOSFET, or metal-oxide-semiconductor field-effect transistor, is a fundamental building block of modern digital electronics. It acts like an electrically controlled switch: a voltage applied to its gate controls whether current can flow between its source and drain terminals. … Continue reading From MOSFETs to the CPU

The computer brains I am quite familiar with now are Arduino, STM32, and Raspberry Pi. They are all computers, but they sit at very different levels of capability. An Arduino is typically built around an 8-bit microcontroller. An STM32 is generally a 32-bit microcontroller. A Raspberry Pi, on the other hand, uses a 64-bit application … Continue reading The Brains Inside the Computers I Work With

A computer program looks very abstract when we write it in C, Python, or another high-level language. But underneath the abstraction, the CPU eventually has to execute a sequence of bits. Consider this simple operation: movl $42, -4(%rbp) In plain English, this means: Take the number 42 and store it at the memory address obtained … Continue reading From Assembly to Machine Code to Electrical Signals

When you have an idea and are able to produce something that people actually want, that is a business idea worth pursuing. It is very different from simply saying that you want to start a business. The real test is whether you can create something useful and get other people to value it. At the … Continue reading Keep Learning and Building

At the foundation of modern computer chips is the MOSFET, short for Metal-Oxide-Semiconductor Field-Effect Transistor. A MOSFET is essentially an electrically controlled switch. By applying a voltage to its control terminal, we can control whether current can flow between its other two terminals. In a simplified view: control voltage │ ↓ MOSFET │ ↓ current … Continue reading From MOSFET to Memory

I recently looked into Microsoft Copilot Studio because Microsoft now supports connecting external MCP servers to it. My first impression was that Copilot Studio is very different from Claude Code, and I think the difference is mainly in the harness. Claude Code is essentially a professional agent workbench. The LLM is surrounded by a strong … Continue reading Copilot Studio or Claude Desktop? the Difference is Harness

Even without an official declaration that “FSD is solved,” FSD has become massively successful. Whether you like Tesla or not, or whether you want to admit it or not, it is difficult to deny the achievement. The remaining obstacles to much broader deployment are increasingly regulatory, legal, and liability-related rather than simply whether a neural … Continue reading From FSD to Humanoid Robots

There are lot of terms like RSA, SHA-256, JWT, OAuth, OpenID Connect, SSO, TLS, and HTTPS. At first they seemed like a collection of unrelated technologies. In fact, they sit at different layers and solve different problems. The easiest way to understand them is to start with the cryptographic building blocks. RSA is a public/private-key … Continue reading From HTTPS to SSO: How RSA, SHA-256, JWT, OAuth, and TLS Fit Together

Machines and computers use different communication protocols because they have different communication requirements. CAN, Modbus, EtherCAT, IP, TCP, UDP, HTTP, and TLS are examples of protocols that operate at different levels and solve different problems. CAN (Controller Area Network) is designed for multiple electronic controllers to communicate over a shared bus. It is widely used … Continue reading How Machines and Computers Communicate

Before PLCs, industrial machines were controlled largely by physical relays. A relay is essentially an electrically controlled switch. Engineers could connect hundreds or thousands of relays, buttons, sensors, and motors to build the machine's control logic. The problem was that the wiring itself became the program. If the machine's behavior needed to change, engineers had … Continue reading PLC: From Relay Wiring to Programmable Logic