Oh, and the (Siemens, at least) trains also take like 30 minutes to boot up. And rebooting a train is often a way to fix problems. So delays can happen because a train is sitting on some important piece of track while rebooting.
This reboot time sounds absurd until you hear the tech stacks running on these trains. I don't remember the details, but it was real Rube Goldberg stuff. Something like System 7 code running on a soft PLS because the real PLS is EOL but the soft PLS can only run on Windows 95 so you run a virtual Windows 95 on top of some obscure hypervisor, and I think there might be another layer to the story as well. Just anything to avoid changing the actual code that runs the train because that would trigger a recertification process.
Especially golden because these operating systems are so good at doing GPIO. This could probably be replaced by a 0.1$ µC by a hobbyist, where the boot time is reduced by 99.999% while being much more robust as well.
Well, perhaps multitasking systems would even be worse at IO than DOS. Not entirely sure here...
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Oh, and the (Siemens, at least) trains also take like 30 minutes to boot up. And rebooting a train is often a way to fix problems. So delays can happen because a train is sitting on some important piece of track while rebooting.
This reboot time sounds absurd until you hear the tech stacks running on these trains. I don't remember the details, but it was real Rube Goldberg stuff. Something like System 7 code running on a soft PLS because the real PLS is EOL but the soft PLS can only run on Windows 95 so you run a virtual Windows 95 on top of some obscure hypervisor, and I think there might be another layer to the story as well. Just anything to avoid changing the actual code that runs the train because that would trigger a recertification process.
Especially golden because these operating systems are so good at doing GPIO. This could probably be replaced by a 0.1$ µC by a hobbyist, where the boot time is reduced by 99.999% while being much more robust as well.
Well, perhaps multitasking systems would even be worse at IO than DOS. Not entirely sure here...