4 ms·

Out of interest, what does?

by ancarda 10y ago

dmoy 10y ago
Just random RT OS's? It's been awhile since I've worked on tiny 8 bit mcus, but all the stuff was really small and seemingly hand rolled, nothing as monolithic as Linux. I would not be surprised to learn that it varies from company to company and chip to chip, with various bits being shared for common logic.
- Tempest1981 10y ago
  I remember VxWorks. Bigger than a while loop, but used in space missions back in the 90s: http://www.windriver.com/inspace/ http://www.windriver.com/inspace/ Edit: looks like VxWorks wants a 32-bit CPU, 128KB of ROM, and 1-2MB of RAM. But you get threads, networking, filesystem, etc.
emidln 10y ago
On the really low end, hardware is often single-purpose and you don't really need an operating system. When there is an operating system (maybe you have to listen to messages from something while performing a previously requested activity), a small hard real-time scheduling library gets used as an "operating system".
marcosdumay 10y ago
There are all kinds of micro-everything circulating out there, from timing and IO drivers to entire network stacks.
foofoo55 10y ago
The almost-smallest devices are powered by LoopOS(tm): while(1){ }
- emidln 10y ago
  So slow and bloated! Get with 2.0: for(;;){ }
nickpsecurity 10y ago
As foofoo said, they often don't use OS's so much as libraries and loops. There are OS's that have been out there for a while for tiniest devices. Contiki is probably a nice intro to different tradeoffs they make in design and features: http://www.contiki-os.org/ http://www.contiki-os.org/ On more serious MCU's, you might see things like VxWorks or QNX: https://en.wikipedia.org/wiki/VxWorks https://en.wikipedia.org/wiki/VxWorks https://en.wikipedia.org/wiki/QNX https://en.wikipedia.org/wiki/QNX As hardware improved, we also saw trimmed down Linux like ucLinux, MontaVista Linux, and so on. It just went from there with increasing complexity (and reboots :).
SEJeff 10y ago
Tron/Etron and variants most likely if any operating system at all. What powers non-smart refrigerators, dishwashers, washing machines, microwave ovents, etc? Tron for many of them. https://en.wikipedia.org/wiki/TRON_project https://en.wikipedia.org/wiki/TRON_project
pjc50 10y ago
Most of the really small stuff is written bare-metal in C or assembler. E.g. http://www.microchip.com/wwwproducts/en/PIC10F200 http://www.microchip.com/wwwproducts/en/PIC10F200 : 384 bytes of code space, 16 bytes of RAM. More constrained than the Atari 2600. $0.31 each, available in 2mm x 3mm packages.

Out of interest, what does?

by ancarda 10y ago

Out of interest, what does?

dmoy 10y ago

Just random RT OS's? It's been awhile since I've worked on tiny 8 bit mcus, but all the stuff was really small and seemingly hand rolled, nothing as monolithic as Linux. I would not be surprised to learn that it varies from company to company and chip to chip, with various bits being shared for common logic.

Tempest1981 10y ago
I remember VxWorks. Bigger than a while loop, but used in space missions back in the 90s: http://www.windriver.com/inspace/ http://www.windriver.com/inspace/ Edit: looks like VxWorks wants a 32-bit CPU, 128KB of ROM, and 1-2MB of RAM. But you get threads, networking, filesystem, etc.

emidln 10y ago

On the really low end, hardware is often single-purpose and you don't really need an operating system. When there is an operating system (maybe you have to listen to messages from something while performing a previously requested activity), a small hard real-time scheduling library gets used as an "operating system".

marcosdumay 10y ago

There are all kinds of micro-everything circulating out there, from timing and IO drivers to entire network stacks.

foofoo55 10y ago

The almost-smallest devices are powered by LoopOS(tm): while(1){ }

emidln 10y ago
So slow and bloated! Get with 2.0: for(;;){ }

nickpsecurity 10y ago

As foofoo said, they often don't use OS's so much as libraries and loops. There are OS's that have been out there for a while for tiniest devices. Contiki is probably a nice intro to different tradeoffs they make in design and features: http://www.contiki-os.org/ http://www.contiki-os.org/ On more serious MCU's, you might see things like VxWorks or QNX: https://en.wikipedia.org/wiki/VxWorks https://en.wikipedia.org/wiki/VxWorks https://en.wikipedia.org/wiki/QNX https://en.wikipedia.org/wiki/QNX As hardware improved, we also saw trimmed down Linux like ucLinux, MontaVista Linux, and so on. It just went from there with increasing complexity (and reboots :).

SEJeff 10y ago

Tron/Etron and variants most likely if any operating system at all. What powers non-smart refrigerators, dishwashers, washing machines, microwave ovents, etc? Tron for many of them. https://en.wikipedia.org/wiki/TRON_project https://en.wikipedia.org/wiki/TRON_project

pjc50 10y ago

Most of the really small stuff is written bare-metal in C or assembler. E.g. http://www.microchip.com/wwwproducts/en/PIC10F200 http://www.microchip.com/wwwproducts/en/PIC10F200 : 384 bytes of code space, 16 bytes of RAM. More constrained than the Atari 2600. $0.31 each, available in 2mm x 3mm packages.