axio.ms is Matt Evans's blog and project-writeup site. All content is copyright © 2002-2024 Matt Evans, unless otherwise stated.
A microcontroller Macintosh This all started from a conversation about the RP2040 MCU, and building a simple desktop/GUI for it. I’d made a comment along the lines of “or, just run some old OS”, and it got me thinking about the original Macintosh . The original Macintosh was released 40.5 years before this post, and is a pretty cool machine especially considering that the hardware is very simple.…
In 1974, Gerald Popek and Robert Goldberg published a paper, “ Formal Requirements for Virtualizable Third Generation Architectures ”, giving a set of characteristics for correct full-machine virtualisation. Today, these characteristics remain very useful. Computer architects will informally cite this paper when debating Instruction Set Architecture (ISA) developments, with arguments like “but…
Built October 2018 I used to hate Cathode Ray Tubes . As a kid in Europe, everything flickered at 50Hz, or made a loud whistle at 15.625KHz (back when I could still hear it). CRTs just seemed crude, “electro-brutalist” contraptions from the valve era. They were heavy, and delicate, and distorted, and blurry, and whistled, and gave people electric shocks when they weren’t busy imploding and…
I’ve always wanted an Apple Macintosh SE/30 . Released in 1989, they look quite a lot like the other members of the original “compact Mac” series, but pack in a ton of interesting features that the other compact Macs don’t have. This is the story of my journey to getting to the point of owning a working Mac SE/30, which turns out not to be as simple as just buying one. Stay tuned for tales of…
Built in November 2015 (now-traditional multi-year writeup delay applied) A hat, bejewelled with 38 RGB LEDs Is this thing on..? It’s been a while since I’ve written one of these. So, the hat. It’s been on the writeup pile for almost 6 years, nagging away. Finally it’s its time to shine ! NO PUN ESCAPES Anyway, the hat. It seemed like a good idea, and I even wore it out dancing. I know, so cool.…
Original concept circa 2008, revisited 2012, hardware designed Feb 2014, firmware designed April-August 2014, project completed August 2014, installed in spare room in 2016, written up in March 2018 (jeeez…) Acrylic, LEDs, ARM Cortex-M0 microcontroller. Colourclock Idea This has been a long-running project. My notebooks contain sketches of the idea from about 10 years back but I finally made PCBs…
Back in February 2014, it was a cold (but dry) winter’s night and we decided to warm our hearts with some science. Our experiment was to observe the conduction of electricity through a pickle, using salt ions. We connected a pickle to the mains supply. Pickles have a strong table salt content, which means a lot of sodium. Sodium, when suitably excited by electricity, will emit light with peaks…
Way back when, I made a cool but basic paper sculpture (in Maths is Fun and Useful ) by hand, using a perl script for the shape template. For cultural reasons, I wanted to make a gift out of paper and it had to be Heaps Good. I had finally got access to a laser cutter (omgomg) and this was my chance to build something similar but doublegood. MATHS IS FUN AND USEFUL, NOW IN ULTRAHD A 3D graph made…
This project was completed in June 2015. Wow, is it 2017 already? In this post, I’d like to say that I wrote a useful little bit of software and built up a crappy hack to demonstrate it but, secretly, the crappy hack came first and I’ve retroactively found something vaguely useful in it. Let’s go: Let there be lights We moved house and needed some temporary* under-cupboard lighting for our…
This is the obligatory “first post on new platform” post, coupled with a bit of “first post in 4 years, I’m still alive”. The original axio.ms site was a very HTML1.0 affair and while this was kind of intentional-tongue-in-cheek-chic, it was also a PITA to update. It wasn’t looking good for regular posts. As well as real life happening, I’ve had a change in job since the last phase of…