Comment by mitxela
14 hours ago
Custom chips aren't as expensive as you think. About a few million dollars for the design and a hundred thousand chips, way out of reach for a hobbyist, but accessible to large enough companies. Just because it's opaque to us software people doesn't mean it's not a real industry you can buy things from.
And all that expensive engineering is still less costly AND faster (!!) than a new software certification.
Cannot refrain myself from asking why ...
Situation: Software-1 on Platform-1, both certified.
Time-evolution: P1 is deprecated, replaced by uncertified P2, but S1 remains certified.. just nowhere certified to run yet.
Solution: There's another software S2 which originally vouched for P1, itself still certified, which can still be used to certify P2.
Counterfactual?: If S1 were deprecated in favor of new S3.. there'd be no plan to certify it!
The problem: None of this actually makes any sense! But we're trying to fake due diligence. Everyone knows the hardware/platforms kinda need to be certified with respect to each other anyway, but if we did it that way it would all be even more expensive an time-consuming.
Doesn't seem crazy to me. Which one do you suppose needs more proof of correctness: a cake recipe, or the oven you bake the cake in? The recipe has to be correct or the cake won't work, but the oven just has to hold a temperature.
Ovens vary greatly. There is no consistency in how even the heat is in the space, the airflow through the space, how much and how fast the temperature varies around the set temperature, etc. These things all do affect how things bake up and often people have to tweak recipes for their specific oven.
In a case where something is safety critical the computer is super important as very subtle errors could cause catastrophic consequences. This is why you get into things like running software on 3+ computers concurrently depending on how fail-safe something has to be.
That "just" is quite the load-bearing seam ...
Particularly when the task here is "just" to measure some rod positions in a constrained 3D space ...