* Posts by Electronics'R'Us

18 posts • joined 13 Jul 2018

Chap joins elite support team, solves what no one else can. Is he invited back? Is he f**k


Airport comms went down

When I was in the middle east many years ago (over 30) I was working on the Air Traffic system. This being a rather large place meant that field trips were fairly common (but try not to drive at night as you might crash into a camel sleeping on the road).

One fine morning. the boss called me in and said that all local radio communications had failed at an airport - the catch was it was 600 miles to the north. I got the company pickup (a GMC Jimmy as I recall) and drove to this place in the middle of nowhere and as it was getting dark booked into a high class (well, high price) hotel.

High class in this instance meant there were less than 2 cockroaches per square foot.

The next morning, thankfully leaving said hotel, I went to the airport and after showing an endless set of security passes, went to the hut where the radios were physically located and spotted the problem quite quickly; a groundskeeper had turned off the main power switch to the hut, so no wonder they weren't working.

The middle east is a place where one must be very careful about the locals with loss of face, so I went in and waited about 30 minutes before turning the main power on again. I did a quick check of the radio performance as I was in the place and had little desire to go there again any time soon.

I wrote up the fault and response as 'primary power adjusted' and then drove back to a well deserved (and illegal) couple of beers.

Airlines in Asia, Africa ground Boeing 737 Max 8s after second death crash in four-ish months


Re: Background

The MCAS system can autonomously control the flying surfaces and should have been analysed for a single point of failure because MCAS should be treated as being safety critical.

The available data suggest that a single erroneous sensor can cause it to push the nose down and that single issue should have caused a lot of concern (and some significant mitigating design work).

Having designed flight control computers, I can definitely say that having a single point of failure potentially cause a crash is completely unacceptable. This is also a major departure from the Boeing philosophy that in case of conflict between the automation and the pilot, the pilot gets control.

Where is the FMECA (failure mode effects and criticality analysis) for this system and for the aircraft? Inquiring minds want to know.

Resistance is... new style: Samsung says it's now shipping resistive eMRAM for IoT chips

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I was in a meeting with the senior management of Everspin about 10 years ago and they were talking about their spin torque parts then as being 'in early beta'.

Glad to see they eventually figured out how to fix the problems to at least ship samples to some customers. One point, though - MRAM of all descriptions is quite expensive right now; hopefully mass production will start sooner rather than later and bring the prices down a bit.

Silent Merc, holy e-car... Mflllwhmmmp! What is that terrible sound?


F-35 in full reheat

Not only is that engine the noisiest in current aircraft, a really good generator would produce a useful pressure wave as well.

What did turbonerds do before the internet? 41 years ago, a load of BBS

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Software tools

I used the Motorola SPS (as it was then) BBS to get the assembler and linker for the 68HC05 series in the early 90s on a blazingly fast 1200bps modem (it was at work); I had to fill out a questionnaire for their CSIC (customer specified IC) program as the cost of getting the otherwise free tools (a rarity back then). "Describe your perfect microcontroller" - choose various core parameters and peripherals.

If you have ever wondered where all the different variants of the various 68HCxx microcontrollers came from, this was one reason.

The part I used (in 1992 as I recall) was a MC68HC805B6, an early flash based part (flash was expensive in them days) which cost (then) over $50 each. I can get far more capable parts today at a tenth or even a hundredth of that. That's progress.

Oh, the final output of the tool was S Records.

HMRC: We 'rigorously tested' IR35 tax-check tool... but have almost nothing to show for it



Citation needed.

The extra tax HMRC want (but are usually not entitled to) is the liability of the hirer, not the contractor (do try to keep up). Contractors with their own companies pay broadly the same percentage of income in taxes as regular employees anyway.

Yes, we get paid more on many (although definitely not all) occasions, but then we don't get paid holiday, sick time or other employee protections. Contractors are often a far more efficient use of company money as we get pulled in for a specific job for a relatively short amount of time and a full time employee would actually cost a company more money.

Dozens of .gov HTTPS certs expire, webpages offline, FBI on ice, IT security slows... Yup, it's day 20 of Trump's govt shutdown


Re: Comparison

That isn't the way the American system works. I lived there for 22 years and studied the constitution as a side line (very interesting stuff).

The budget is required to originate in the house of representatives (the only such bill specifically called out in the constitution), and it was originally envisaged that the executive (president) would be the weakest of the three branches of government.

The President has no power to make laws (he can invoke an emergency but that is specifically permitted in certain circumstances); he (and the rest of the executive) are supposed to actually execute the laws. He can shout all he wants but the only people he is hurting are the federal workers who have no paycheck in sight (apart from his own reputation but as he is pretty well heeled he can afford to retire anyway).

Only congress has any power to actually make any laws (including the appropriations bill). The president can refuse to sign a bill but if the house and senate vote with a 2/3 majority after that, it will become law without his signature.

It's the wobbly Microsoft service sweepstake! If you have 'Teams', you've won a lifetime Slack sub


Teams as an "upgrade"

My Skype for business (as poor as it was) had all the basic functionality I needed. I then got notifications

You are being upgraded to Teams!

When I saw the horrible mess that passes for a user interface, it was promptly deleted. Much more complex to use, a crappy UI and a resource hog.

Shame really as it is part of the subscription, but I cannot see any practical use for it that I cannot get elsewhere with a far superior experience.

Boeing 737 pilots battled confused safety system that plunged aircraft to their deaths – black box


Re: Really?

Automated control of aircraft has been with us for decades; having designed flight safety critical systems, I am astounded that this particular subsystem was not comparing both AOA sensors. In a 'disagree' situation, the system should simply raise an alarm (MCAS offline?) so the aircrew know something dodgy is going on.

It should be inconceivable that a subsystem capable of changing the control surfaces is not redundant.

That said, as the crew did not even know of MCAS, they might get confused with "What the hell is MCAS?"

To me, this is a fundamental design flaw that should never have got past the independent technical authority even within Boeing, let alone by the FAA designated representative.

The flight control system on the 777 is a triple redundant system, incidentally (with different processors in each lane at that).

Decoding the Chinese Super Micro super spy-chip super-scandal: What do we know – and who is telling the truth?


Re: Grikath

If we are being paranoid enough to check this stuff, wouldn't we be paranoid enough to check that what is in the chips matches what we expect to be in chips?

In some industries, we do that all the time because of component counterfeiting (a major problem for kit that needs to be available for 20 or more years),


Re: 'None of the actors can be taken at face value

The short answer is it can be done, but at PCB fabrication, not assembly of the entire board.

We have been embedding small components inside PCBs for quite a while.

Redis does a Python, crushes 'offensive' master, slave code terms



To say nothing of the (probably) 10s of thousands of schematics already done with those names.

Let's not forget about the netlist too - will the manufacturers get offended at netlist test when they make sure that a MISO connects to another device MOSI?


What next?

Are we going to get lots of requests to change the naming of pins on hardware SPI interfaces from the perfectly descriptive MISO/MOSI?

Or perhaps the Power architecture mnemonic EIEIO being offensive to farmers? (I remember seeing a comment in the source that said // Old Macdonald had a farm).

How about slaved power supplies for proper sequencing should be renamed? Dependent? (Can't have that, implies economic status)

Maybe the term 'bit twiddling' can be offensive (sexual incorrectness)

The list goes on; these terms are used because they perfectly describe the relationship in hardware.

Get a grip! (Oh, is that offensive too?)

Microsoft: You don't want to use Edge? Are you sure? Really sure?


Re: Windows is not always optional

"Are the toolsets able to run on wine or a VM?"

That depends on the processing power and memory you have. Running natively on Win10 my tools use the best part of 8GB without doing 'special' stuff. This is a (logical) quad core machine and even so startup and entering a new mode can take quite a while. Most of the engineering tools I know of (be they CAD, heavy duty simulation (think hyperlynx) or whatever) recommend at least 16GB memory installed.

The graphics are also pretty intensive, as would be expected for a CAD tool.

I haven't tried to run these tools in a VM yet; perhaps I will try and see what happens, but I am not particularly hopeful as these tools typically get as close to the graphics hardware as possible.


Windows is not always optional

Don't get me wrong; I really like Linux (and even write code for it sometimes), but my CAD tools (I design hardware too) are Windows only.

Yes, there are alternatives, but for the feature set I need I would need to fork out at least another £10k for the tools that can run on Linux (there is at least one professional toolset that does), and the feature sets of the free / open alternatives simply are not up there - yet.

That said, I do limit my time in Win10 to only when I need to use tools that are Windows only.

Criminal justice software code could send you to jail and there’s nothing you can do about it


Previous issues with 'trade secret' software

In 2005, a judge ruled (upheld in US circuit court) that a DUI defendant had the right to have the breathalyzer source code revealed and reviewed.

Perhaps this software might be subject to the same analysis.


Insecure web still too prevalent: Boffins unveil HSTS wall of shame


https helps prevent this

Comcast (amongst others, apparently), likes to inject their own code to websites requested.


AR upstart Magic Leap reveals majorly late tech specs' tech specs


There is more to these than processing power

Having done quite a lot of work on helmet mounted and head mounted displays, it is clear that these people do not understand the system level latency problem.

There are helmet mounted displays in a number of applications for military aircraft (Typhoon and F-35 come to mind), and the architecture to achieve a smooth transition when the pilot moves their head around is anything but easy (but rater necessary as there is conformal data such as is displayed on a HUD like heading, aircraft attitude and altitude to name a few). This issue has to be solved at system level and virtually no amount of processing grunt will save them from this issue if the data paths have not been carefully constructed.

Another issue is pre-distortion of the imagery because displaying on a curved surface requires the image to be manipulated to appear to be flat and that adds latency as well quite apart from getting the video from sensors in the first place.

Seems like they need to go back to a drawing board and analyse their various path delays.

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