London's runs on iRMX III. The hardware is x86 but non-PC, based on Multibus. https://en.wikipedia.org/wiki/RMX_(operating_system) https://en.wikipedia.org/wik

London's runs on iRMX III. The hardware is x86 but non-PC, based on Multibus. https://en.wikipedia.org/wiki/RMX_(operating_system) https://en.wikipedia.org/wiki/RMX_(operating_system) That OS was pretty much a feature demo OS for the x86. All that task switching stuff is used to the max, and of course the segments are as well. Good luck porting anything, even if you did have the source code and a budget. Also, the popular language was PL/M, which is impressively awful. https://en.wikipedia.org/wiki/PL/M https://en.wikipedia.org/wiki/PL/M