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A µSD, slave SPI, and DMA
Connecting an SD card to a Blue Pill was described in a recent article. With the sdcard.fs code, it’s as simple as calling sd-init, and then sd-read / sd-write for accessing 512-byte blocks.And since...
View ArticleThe virtual floppy jukebox
Times sure have changed: a fingernail-sized 2 GB µSD card of a few dollars can now easily store over a thousand 1.44 MB floppy disk images, while being quicker than the fastest hard drive from the...
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Circular motions
Just back from a few days in Paris, visiting friends (a bit south of Paris, actually), but we did manage to squeeze in a stroll in the Jardin du Luxembourg - with memories of a (brief) childhood there,...
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The limits of Mac and Mouse
It all started with recent kernel panics on my MacBook Pro laptop, almost every night, causing me to revisit my setup and choice of technologies. For the record: I’m very attached to my 2014-era “MBP”,...
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Just a bunch of opinions
This week, I’ll report about some progress on the next EZ-Retro “v2” PCB and build (which isn’t quite right yet, unfortunately).But first, a topic which has been keeping me busy lately… typing and the...
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Why Vim is very different
Ah, the smell of editor wars. Arguments collide. Opinions galore. Lots of heat, so little light…This article was not written for the sake of argument. I just want to highlight why I keep coming back to...
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Taking it further with i3
This article is about the i3 window manager (and also, further down below, Ranger):Its main distinguishing feature is that is uses tiling as visual layout mechanism.While the mouse and...
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EZ-Retro v2, now with a PCB
As mentioned earlier, the EZ-Retro project could use a PCB for a more compact and robust setup. There is a nice F103 board variant (search for “STM32F103C8T6 ARM Minisystem Development Board STM32“ on...
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Troubleshooting the EZ-Retro
Here is the eZ80 chip, hand-soldered on the new EZ-Retro v2 PCB:The trouble is: something is very wrong: with my lab power supply set to 3.3V and a 30 mA maximum current limit, the voltage drops to...
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Mecrisp Forth's memory use
The Blue Pill is a widely available and extremely low-cost STM32F103-based µC board which has an amazing amount of features and plenty of memory onboard: 64K flash and 20K RAM.In C/C++, the way...
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Back to Forth explorations
Now that the EZ-Retro project is beginning to wind down, I’ll start exploring Forth’s features and behaviour a bit more again.One of the distinguishing features of a fully self-hosted system like...
View ArticleFolie is growing up... slowly
Folie, the “Forth Live Explorer” is starting to shape up. Here’s a summary of what it’s about:a front end for Mecrisp Forth, i.e. a terminal emulator like picocom or Tera Termeasily find (ctrl-R) and...
View ArticleF103 + USB = Swiss Army Knife
The USB driver for STM32F103 has been around for months and it’s proving to be very stable and usable. The current Mecrisp release now includes it, and there’s an F303 port available.The original code...
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Some Mecrisp Forth utilities
This week, I’m going to demonstrate some tools from the Mecrisp Forth distribution.A different prompt, math functions (even without hardware floating point), random numbers, call tracing/profiling, and...
View ArticleSimple Mecrisp Forth utilities
The default message shown after a reset of Mecrisp Forth is this prompt:Mecrisp-Stellaris RA 2.3.6 for STM32F103 by Matthias Koch Nothing else, no hint that you can start entering commands. With a...
View ArticleLet's trace, profile, and patch
Although Mecrisp Forth “compiles” source code to machine language, it’s not really a compiler in the traditional sense, as with say C or C++. In Forth, the compilation process and runtime execution are...
View ArticleGenerated code & performance
Let’s look at how the tricks in the previous article end up in code, and their performance effects. First the trace.fs itility, which needs to insert special calls at the start and end of each word:: a...
View ArticleThink, upload, rinse, repeat
As often mentioned, Forth enables an interactive development approach: you enter commands on the µC itself, and things get done right away. No make, no compile step, no uploads.But that’s an...
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Going through the motions
The last word in last week’s introductory weblog post was “flow”. Let’s talk about that for a moment: what is it like to develop a Forth application for an embedded µC, and in particular a remote...
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Multi-platform development
The title of this article is perhaps a bit misleading: it’s not just about developing code which needs to run on different platforms, it’s also about using different programming languages.Over the...
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