MO5

For this vibe coding session, I decided to test Copilot Pro, taking advantage of the few free trial days. And to put all the chances on my side, I started directly from Olivier P’s repository: 👉 OlivierP-To8/BootFloppyDisk My objective With ChatGPT, I hadn’t managed to create my own code nor to use Olivier’s project to generate a working disk image for the MO5. Yet, in theory, everything seemed simple: I take the same source, copy it into my repo, compile it, use Olivier’s tools… no reason for it to break. ...

As part of my job, I had the opportunity to test Augment. During those professional tests, I found it very relevant, almost “proactive”. By proactive, I mean: not only answering the request, but also anticipating unexpressed problems, proposing alternative solutions, and drawing attention to critical points… you get the idea. I was honestly impressed. Augment offers a 7-day free trial for its coding agent, which was perfect timing: I was planning to run my experiments over the weekend anyway. ...

After my experiments with Augment, I had an idea in mind for a few days. Create my own C library to make development on the MO5 easier. Nothing huge. Just something to avoid rewriting the same bits of code over and over again. Augment had already generated a few utility functions. But the ones that felt truly fundamental to me were these: char mo5_getchar(void) { asm { swi fcb $0A } } void mo5_putchar(char c) { asm { ldb c swi fcb $02 } } In my head, everything started from there. Those two functions as a base, and then rebuilding the rest around them. ...

Following Day 7, I reached an important milestone in my exploration of C development on the Thomson MO5: I finally had two fully functional tutorials. They were still simple, but they were stable, reproducible, and understandable. At that point, they relied on two very different approaches: one tutorial using my home-made string, stdio, and ctype libraries another tutorial based exclusively on cmoc.h It was the right moment to step back and analyze what CMOC really provides. ...

In the previous episodes, I talked about my RAG server, why it exists and how it helps me provide context to AIs. But as my experiments progressed, I realized an important point: a RAG server, no matter how well built it is, is not sufficient for a smooth and robust integration with modern AIs. There is a missing building block to connect coding agents to my RAG server. In this article, I will explain: ...

Following the previous episode (/mo5-blog/days/day-6-rag-server/), I wanted to go one step further: deploy my RAG server on the Internet. The goal was twofold: make the server accessible from the outside allow coding agents (Copilot, Augment, etc.) to have a precise context to help with MO5 development (the project is described here: https://retrocomputing-ai.cloud/) Deploying a RAG, but not just an API To connect coding agents with my RAG server, I created an MCP server. It acts as a standardized interface between AI tools (Copilot, Augment, etc.) and my RAG API. ...

Creating a MO5 template to stop fighting the build Lately, I had way too many topics open at the same time. Way too many 😅 In no particular order, there were: continuing my experiments to better understand how graphics mode works on the MO5 completing the documentation of my RAG server modifying that RAG server to simplify keyword management, then redeploying it with the new documentation hosting my MCP server building a small graphics-mode game on the MO5 And in the middle of all that, a very down-to-earth problem kept coming back: ...

On this new day of MO5 coding, I did quite a lot of things, and especially a lot of experiments around graphics mode. Generating sprites from images I tackled a fairly classic problem: drawing sprites in C for the MO5 is… how can I put it… not the most fun thing 😅 At first, I went for a very “handcrafted” approach: drawing in text mode via Notepad, with a space for the background color, an X to draw the shape color, then using a PowerShell script to transform the text into a bit array. ...

That’s it, I’ve started making tutorial-style videos 😉 I recently discovered GitHub Codespaces, and wow… instant crush. GitHub Codespaces, the trigger Being able to have a complete Linux environment in the cloud, accessible from a simple browser, is just amazing. No complicated local installation, no exotic dependencies breaking everything, no more “it works on my machine”, everything is ready in seconds. This opportunity made me want to create a tutorial explaining how to use my template to develop in C for the MO5. ...

This weekend, I intended to tinker with a small Space Invaders style game. I had already developed a basic function to display sprites, but this time I needed something cleaner, faster, more optimized. In theory, the idea was simple. I wanted a rendering function capable of handling transparency, meaning it would not touch the background color, and a clean function that would only need to write 0 into the shape bank to erase the sprite, without ever modifying the color bank. ...

If you’ve followed my previous adventures, you know that coding on MO5 is… intense ;) Between tools from another era, hardware constraints that are not always well documented, and different behaviors between emulator and real hardware, I spent quite some time fighting my environment. At some point, I realized something simple: I was spending more time fixing my tools than coding my game, and that is frustrating. The real problem At first, I thought the problem came from the MO5: old machine, strong constraints, makes sense. ...

I thought I understood the MO5. In reality, it was the MO5 testing me 😉 Since I started developing my little game, I’ve run into quite a few issues, some predictable, others completely absurd, and most importantly several traps I fell into… even though I already knew the theory or had already experienced them before. That’s probably the most frustrating part. You know the trap exists, you’ve already read about it somewhere, but you still fall into it anyway. ...

Since I started tinkering with the MO5, I’ve learned quite a lot, sometimes the hard way, often by spending my evenings on it 😉 I documented all of this on this blog, step by step, sharing what I discovered, the problems I ran into, and most importantly the solutions I found to make development a bit more… enjoyable. Because let’s be honest, coding on MO5 today, without the right tools, can quickly become complicated. ...

After building my MCP server, I figured it would be a shame to leave it sitting in a corner. An unlisted MCP server is a bit like a restaurant with no sign out front. It exists, but nobody finds it. 😄 So I decided to publish it in the MCP registries. And as usual… it was “straightforward” 😅 What’s an MCP registry? An MCP registry is a directory of MCP servers. Coding agents (Claude Desktop, Cursor, Augment…) can connect to it to discover and install servers. ...