Everything important is using ECC and low-level parity bit protection.
in a perfect world, perhaps. but we don't live in one.
Are PDP-11 computers still in use?
The PDP-11 is definitely still in use today, thanks to its unique and strong build. It is still used to power a GE nuclear power-plant robotic application — and will do so until 2050.
Technically, due to its potency, it is still used by the US Navy in its ship radar systems and by Airbus SAS. There are also rumors that it is part of the set up in the British Atomic Weapons Establishment.
Thanks Intel for making this statement false
These have a high probability of working but it isn't perfect. And not all of them tell you which way the bit was flipped.
Ok, I'll bite: what's a "cosmic ray bit-flip"?
So basically, we have low level neutron radiation coming at us at all times from space. Mostly from our own sun, some other external sources too. It takes a whole lot of concrete or lead or water to stop that completely, so anything that makes it through our atmosphere is harmlessly passing through all of us.
But since things like computer RAM and other electronic storage have gotten so much smaller, this radiation is now capable of energizing or discharging individual bits — 1s or 0s — in that storage. Imagine you’re in the hospital for a back operation and the robot arm is approaching a 1 bit that tells it to stop… but that 1 flips to a 0 because the sun sneezed and now your spine is in two fun-sized pieces.
This is all mostly moot today, though. ECC-enabled RAM (memory with protections against bit flips) is the norm and this is a pretty well-understood problem.
Nearly every computer you use, including the ones people are starting to use for self-driving, can have their memory accidentally modified from cosmic rays
We try really hard to protect spaceships from them, since they’re subject to more
However, due to the law of large numbers, sometimes your computer will get random bit flips - where it should be a 0, but it’s instead a 1, or vice versa
Cosmic ray zaps your silicon just right to flip a bit. If you've heard of the Tick Tock Clock upwarp in Mario 64, most people suspect that's what happened.
On first thought : yes.
But on second thought : no (i.e. : not really, because of system's redundancies)Imagine this happening today...
The real Y2K
I thought we already had a way to deal with bit flips. CPU bit flips should be common by now because of the size of processors these days.
Yup. There is technology to deal with this. But does every piece of hw have that tech? No. Does every piece of sw run eccs for this purpose? No.
