EmuTOS is a like-for-like replacement for the ST OS, using some of the Digital Research PC GEM code that was open-sourced by Caldera around the turn of the century.

So it's a single-tasking OS.

ST TOS evolved in multiple directions, with a couple of complete replacements, such as MagiC, itself now FOSS: https://en.wikipedia.org/wiki/MagiC

People replaced various bits of TOS and GEM, which had a fairly clean layered design. A decade or so back, a project united various FOSS replacement bits for chunks of the Atari/DR stack, wrote some more code to fill in the blanks, and released an all-FOSS Atari-compatible OS.

It's called AFrOS: Atari Free OS. https://aranym.github.io/afros.html

It uses MiNT, a multitasking Unix-like layer that turns Atari GEM into a multitasking OS.

The first time I heard of EmuTOS was basically as a bootloader for AFrOS. I'm delighted to learn it has grown into a complete TOS replacement, but TOS itself evolved into a whole new sort of OS and that has resulted in a complete FOSS ST OS years ago.

EmuTOS is much more like the original OS.

AFrOS mainly is intended to run on a dedicated emulator, called ARAnyM: Atari Running on ANY Machine. https://aranym.github.io/

ARAnyM doesn't aim to be a completely accurate ST emulator for running ST games. Instead it's aimed at people doing serious productivity-type work in GEM, and aims to run GEM apps quickly on modern hardware, at the price of losing perfect hardware compatibility.

Those interested in Atari OSes may enjoy AFrOS on ARAnyM. I certainly do.

It sounds good, the other one is AROS based on the M68K Amigas: https://aros.sourceforge.io/ they have an Intel version and one that runs on M68K Amigas with a replacement Kickstart ROM that is 100% open source and free.

I quite liked the Atari 520ST, and this seems like a great way to get an emulator going. What is out there that would run well on a Pi?

Hatari is a very stable ST emulator, I highly recommend it, i've had a lot of nostalgic fun with it. Although I've never tried EmuTOS before.

EmuTOS runs fine on Hatari on my Mac (never tried EmuTOS on real hardware). One thing to bear in mind is that some software, especially games, might not run on EmuTOS, but you ought to be able to find real TOS images without too much hassle.

It's nice to be able to read the source for EmuTOS as well (though I would love to see the source code for the real TOS).

One thing that I found really weird about the EmuTOS source is that the dependencies for certain system calls go in the wrong direction. For example, certain linea (primitive graphics) routines depend on functions in the VDI (high level graphics library), whereas I would have assumed that the dependencies would go the other way. Presumably they had reasons for doing that but it seemed odd to me when I discovered it.

I really enjoyed playing with Hatari and EmuTOS when I discovered them. I learned to program on an Atari ST when I was a kid and I still feel really sad that the platform reached a dead end and died back in the early 90s.

> I learned to program on an Atari ST when I was a kid and I still feel really sad that the platform reached a dead end and died back in the early 90s.

Funny, I also picked up an ST when I was a kid, but in the mid 90s when it was already considered dead :D I'm actually very grateful I got that instead of a windows machine that had reached dominance at the time. All of the other kids thought windowspc==computer and had no exposure to Basic or anything. I found the Atari a lot more fun, creative and broadening of what "computer" meant to a kid at the time by it's mere differentiation.

That little green desktop will always have a place in my heart. https://www.dwitter.net/d/19166 https://www.dwitter.net/d/21735

What languages did you use on the ST? I cut my teeth on STOS, GFA BASIC and DevPac 2. Learning assembly language, which I was trying to use to write games, proved to be very useful when I later worked on embedded systems. Though I never managed to produce a properly playable game in assembler.

I run EmuTOS on my OG Atari STe. It's quite excellent, especially compared to Atari TOS.

oh nice. I might have to give this a try too. I'm particularly drawn to it because, from their website, it says it's bootable from floppy (ie doesn't require a custom ROM chip). Which is really appealing.

So whatever happened to the Suska project?

great question. Never knew about Suska. My guess is that it's just not worth it to build custom boards when you can use MISTer with a commodity FPGA dev board.