3 ms·

That's surreal - avionics should run on hard real time. (Whether it's offline scheduled and thus "impossible" to miss a deadline, or if it's "soft" realtime and

That's surreal - avionics should run on hard real time. (Whether it's offline scheduled and thus "impossible" to miss a deadline, or if it's "soft" realtime and merely testing ensures this, is not the important part. The important part is that it should never miss a deadline.)

raverbashing 7y ago
I can understand it looks weird but it isn't. A faster processor has no more real time guarantees than a slower processor from the 80s Of course, the faster one can do more stuff in less time, but for flying an airplane (or going to the moon) the amount of computing power needed is much less than people imagine. The issue here is adding more computing into an aging platform. But there's nothing inherently wrong into using an older platform into the flight computer. Now I'm not sure if for certification purposes they would be allowed to replace it with modern hardware but just keeping the functionality the same, I believe the answer would be yes, that they are allowed (but they probably didn't want to rewrite the sw and recertify the hw)
- wiz21c 7y ago
  is it me or the certification looks at the hardware but not at the software ?
  - raverbashing 7y ago
    Certification mostly looks at the behaviour, how you get there is your IP for the most part For example, the regulator doesn't care (much) how you built your wing, but it does care that's able to withstand 150% of the maximum expected forces. You can have parts done by different manufacturers (but to the same spec) and this is sometimes done on purpose in redundancy settings so that unknown bugs in one model are less likely to show up in a different model.
- jacobush 7y ago
  Processing has very little to do with hitting realtime deadlines. Either you do or you don’t. In fact, sometimes faster CPUs are worse for realtime because their latency can be worse.

raverbashing 7y ago

I can understand it looks weird but it isn't. A faster processor has no more real time guarantees than a slower processor from the 80s Of course, the faster one can do more stuff in less time, but for flying an airplane (or going to the moon) the amount of computing power needed is much less than people imagine. The issue here is adding more computing into an aging platform. But there's nothing inherently wrong into using an older platform into the flight computer. Now I'm not sure if for certification purposes they would be allowed to replace it with modern hardware but just keeping the functionality the same, I believe the answer would be yes, that they are allowed (but they probably didn't want to rewrite the sw and recertify the hw)

wiz21c 7y ago
is it me or the certification looks at the hardware but not at the software ?
- raverbashing 7y ago
  Certification mostly looks at the behaviour, how you get there is your IP for the most part For example, the regulator doesn't care (much) how you built your wing, but it does care that's able to withstand 150% of the maximum expected forces. You can have parts done by different manufacturers (but to the same spec) and this is sometimes done on purpose in redundancy settings so that unknown bugs in one model are less likely to show up in a different model.
jacobush 7y ago
Processing has very little to do with hitting realtime deadlines. Either you do or you don’t. In fact, sometimes faster CPUs are worse for realtime because their latency can be worse.