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Comment I have had first-hand experience (Score 1) 138

I am an HVAC controls Technologist and the product we use used to have an unintentional DOS issue. If there was too much traffic on the controller's network port (including traffic not intended for it), the processor would spend all of its time responding to network interrupts and actual operation would grind to a halt. The fix was simple...the manufacturer made new firmware that would simply ignore network interrupts if the program scan rate got too low. Sure, the controller would quit communicating on the LAN but it was still accessible via rs-232/485.

These controllers have 32MHz processors, 2MB ram, and 10Mb half-duplex ethernet, and cost multiple thousands of dollars.

Comment Re:Seatbelts? (Score 1) 74

Why do you keep talking about the seatbelt locking? It's an irrelevant argument. They still always lock mechanically, no software involved. Your seatbelt isn't going to just unwind and let you smash into the dashboard unimpeded if the software fails to fire the airbag/pretensioner.

What is controlled by software is the pre-tensioner that explosively shortens the seatbelt to pin you into your seat so you are better positioned for airbag impact. This absolutely must be integrated into the airbag system, and only electronic control allows accurate enough timing to make it effective.

Comment Re:Seatbelts? (Score 2) 74

I don't know the stats on pretensioned seatbelt injury. The seatbelt pre-tensioner is part of a system; it doesn't necessarily kill people on its own, but it has the potential cause unwarranted injury and distraction. The SRS system as a whole definitely can cause severe injury and death. That's why they are always being improved. No one wants their explosive seatbelt tensioner to fire in non-collision conditions. It also needs to fire in coordination with the airbag to be effective; if it fires too late or doesn't fire at all it doesn't help. The SRS system needs to completely deploy in the correct order for the conditions within around 70ms of the first impact. Electronics are the fastest, most accurate, and repeatable timing system available.

Comment Re:Why are they using software (Score 3, Interesting) 74

Isn't some simple mechanical fuse / switch sufficient for the airbag deployment system? Also, did old cars require SDM for the seatbelt to lock properly? Why are they changing mechanisms that have proved themselves?

Isn't a carburettor and magneto sufficient to run an engine? The answer is yes, if you have no regulations, reliability and/or liability to be concerned with.

Air bag systems have had software for literally decades, it's not new. Seatbelts still have mechanical locking. Electronically-controlled pre-tensioning is something else that has been around for decades now, and is part of the airbag control system.

Modern air bags have variable deployment energy, which requires determining the severity of the collision, the weight of the occupant, etc. There are also side curtain and many other types of airbag that should only deploy when required, so the pitch, roll, and yaw, and even sideslip of the vehicle has to be known. Side curtain airbags need to deploy before the vehicle lands on its side, so software is required to predict when impact is likely to occur.

Also, electromechanical systems can't self-check and diagnose themselves when there is a system failure. Air bag systems continuously monitor even the resistance of the igniter in the airbag to make sure it is correct.

As vehicle manufacturers found out with carburettors and emissions regulations, mechanical systems quickly become too complex and unreliable to react to many inputs. There is no new passenger vehicle sold in North America that doesn't run its engine entirely from a computer. It's just that superior. Likewise with airbags.

Comment Re:Seatbelts? (Score 1) 74

Because without software, seatbelt tensioners and airbags would deploy in many instances where and when they should not. These systems have to be very complex in order to not kill people inadvertently. Hence, self-diagnostics tests and the like. The state of the vehicle is modeled to determine the probability of a crash being in progress in order to make sense of individual sensor input.

Comment Re:ARGH (Score 1) 720

Virtualizing old versions of Windows is probably a breach of contract, as the OS is only allowed to be installed on the original computer. According to MS, only the original receipt is proof of license as well. Volume licensing could be different, but I imagine a valid volume license for Windows 95 doesn't exist today.

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