Sylphide OS: a general-purpose OS for microcontroller-based computers

Sylphide OS is a general-purpose Operating system for computers made from microcontrollers (MCU).

Lacking MMU, those boards are usually not able to run a full-fledge modern operating system such as Linux.

Yet they are now powerful enough to provide an environment very similar to home computers as we knew them from the 80's.

Retrocomputing is all the rage nowadays, but it can mean a lot of different things.

There are people "restoring old computers" (mostly for playing and collecting), typically telling you that emulators dont feel genuine enough for their old memories.

Others, die-hard electronic freaks, are interested in 'recreation' of old computers, either with modern components (cheap, easy to source), or on the contrary with era-exact chips for those who can afford them.

There are emulators of all kind, at different layers (pure-software, FPGA based, cycle-accurate or higher level, ...). You can even find online emulators for almost all platforms before 1990.

Some are developing software, usually games, using modern computers and software, but targeting old computers.

This project is about yet another way: computers using modern microcontollers. There are cheap and more and more common. And of course we expect more will be available.

Traditionally, computers are based on powerful processors, with lot of peripherals, more importantly keyboard, screen and mouse, while microcontollers are a lot less powerful, packing a small core with very little RAM and lot of embedded style peripherals on the same chip. Things like UART, SPI, ADC, I2C, counters, timers, and so on.

But of course, as technology evolves, the difference got blurred, and we start to see microcontrollers that can handle "computer-like" system design. It's not so much about compute power (MCUs have been very powerful from some time already), but rather about being able to output to a standard display like VGA or HDMI, rather than nothing, SPI-based small LCD screens, or DSI. To a lesser extent, input can also be challenging, lot of MCUs just have no USB host capability, and when they do, only one port can be used. You want at least two for keyboard and mouse, and ideally a third one for usb key.

When you manage to get all of that, you still have a severely constrained environment (low ram, low colors if any). It really feels like early computers from 80's/90's, both as a user and as a programmer. This is exactly the kind of 'retrocomputing' I'm after.