EEVblog #893 - Mailbag

[boffin]

Casual racism, not funny.

What are you talking about?
Are you saying I said something racist?

Apparently not; according to the New Zealand Advertising Standards Complaints Board.
http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10334691

[Brumby]

Casual racism, not funny.

What are you talking about?
Are you saying I said something racist?

Apparently not; according to the New Zealand Advertising Standards Complaints Board.
http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10334691

Not quite the same scenario.  In that complaint the term "sheep shagger" was directed at a ram.  As such, the term expressed nothing more than a reference to normal, expected behaviour in the animal world - perhaps indelicately and with an indirect reference to something else.  Using the same term in reference to humans, is quite direct and has a bit more to it.

It's a phrase I don't use.

[nwvlab]

Glad to see Dave having the same organic PV modules on which we are performing reliability tests

Are they any good?
What's your app?

We don't have any application for them: we performed accelerated reliability tests as a part of a collaboration with DTU (Danmarks Tekniske Universitet).

Their reliability is good, especially if you consider they are organic and manufactured using roll2roll techniques. Still, don't expect a 10-year lifetime

By the way, InfinityPV had a successful kickstarter project some months ago (Heli-On), a solar-powered battery charger. So I expect they reached a good level of reliability (at least compatible with the 2-year warranty required by EU).

[apis]

Maybe you Australians should use that moniker for people from another part of the commonwealth
https://linkbeef.com/3-farmers-arrested-in-wales-for-running-sheep-brothel/

[TheSteve]

That BEC. The output voltage is fixed. Don't calculate the power by multiplying the input voltage with the output current.

And I've no doubts it will meet its rated claims - it's made by one of the best(if not the best) companies in the RC business.

[jb79]

Hi Dave!

As some viewers of the video allready stated, you mixed up input voltage and output current.
The BECs used in model airplanes/helicopters are used to power the servos and motor controllers to control the airplane/helicopter. So the output voltage is about 5V, in some cases a little bit more (6-8V in this case).

50V in a model plane/helicopter is not common, but large electric power models need such high voltage to get enough power. Usually this are 12S Lipo packs with 44,4V nominal voltage, that would be 50,4V when fully charged. For example a 12S, 5000mAh pack with 30C would deliver 150A with 44,4V, that are 6660W of power. That's enough for aerobatic model planes up to 12kg.

I think it's no complete bullshit, (only using a 50V capacitor for 50,4V input voltage). I only think the full output power won't be reached (maybe 2/3-3/4 of it might be possible).

If the voltage is set to 8V and we assume an efficiency of lets say 85%, the maximum output power and heat of the BEC would be:
16V: 15A*8V=120W => 21,2W
24V: 13A*8V=104W => 18,4W
32V: 11A*8V=88W => 15,5W
40V: 9A*8W=72W => 12,7W
48V: 8A*8V=64W => 11,3W

Can you do a short measurement with electronic load, to see if I'm right with the estimation of 2/3-3/4 of the rated output currents?

I've also found the datasheet of the controller, a LTC3824

[German_EE]

Regarding the 'racism' thing. As a schoolchild in the UK we had a German kid come to stay with us for a week or so. He spoke perfect English and my brother and I quickly discovered that all the jokes he told about the Poles were the same ones that we told about the Irish. It would not surprise me in the slightest if the same thing happens between the Canadians and the Americans, the Americans and the Mexicans, the Australians and the New Zealanders, the South Koreans and the North Koreans etc etc.

There is therefore a choice of methods if you find yourself on the wrong end of a joke like this:

a) Laugh it off and say something funny back

b) Grow a pair

c) If you really must, complain like a spoiled kid that someone called you names.

I am quite sure that if a New Zealander is called a sheep shagger to his face that there are an ample supply of jokes against Australians, they have had a few hundred years to practice since the first convicts arrived.

[roffvald]

Regarding the 'racism' thing. As a schoolchild in the UK we had a German kid come to stay with us for a week or so. He spoke perfect English and my brother and I quickly discovered that all the jokes he told about the Poles were the same ones that we told about the Irish. It would not surprise me in the slightest if the same thing happens between the Canadians and the Americans, the Americans and the Mexicans, the Australians and the New Zealanders, the South Koreans and the North Koreans etc etc.

There is therefore a choice of methods if you find yourself on the wrong end of a joke like this:

a) Laugh it off and say something funny back

b) Grow a pair

c) If you really must, complain like a spoiled kid that someone called you names.

I am quite sure that if a New Zealander is called a sheep shagger to his face that there are an ample supply of jokes against Australians, they have had a few hundred years to practice since the first convicts arrived.

We have the same thing in Norway with the Swedes and vice versa.

[bookaboo]

Regarding the 'racism' thing. As a schoolchild in the UK we had a German kid come to stay with us for a week or so. He spoke perfect English and my brother and I quickly discovered that all the jokes he told about the Poles were the same ones that we told about the Irish. It would not surprise me in the slightest if the same thing happens between the Canadians and the Americans, the Americans and the Mexicans, the Australians and the New Zealanders, the South Koreans and the North Koreans etc etc.

There is therefore a choice of methods if you find yourself on the wrong end of a joke like this:

a) Laugh it off and say something funny back

b) Grow a pair

c) If you really must, complain like a spoiled kid that someone called you names.

I am quite sure that if a New Zealander is called a sheep shagger to his face that there are an ample supply of jokes against Australians, they have had a few hundred years to practice since the first convicts arrived.

In Ireland we tell Irishman jokes 

[Brumby]

In Ireland we tell Irishman jokes 

It's true!

I'm on another (much smaller) forum and we have one Irishman there who rolls out jokes on a regular basis - and a lot of them are about Irishmen!

You've gotta love the Irish!

[bitwelder]

Isn't already racist to segregate New Zealand population into a 'race' ?

[Conseils]

Many years ago I wrote DOS and windows 3.1 software that was protected with one of those keys..
As I recall there were two ways to implement protection:
 1) Write stuff into your source code sending a number and getting something back, also make noise on the exchange for obfuscation
 2) Allow their software to add stuff to the .EXE file and manage the issue

There were at least two types of key, cheap and expensive (easy to crack and harder). There was also a master key if I recall in the developer pack with a clear window in it where you could see the IC package. I seem to recall there were a few bytes of storage on the more expensive model.
After a full 30 seconds of research...
https://sentinel.gemalto.com/software-monetization/sentinel-hl/

Some pirating software would remove some vendors 'added code'. At one place I worked at, my boss bought this thing that recorded what happened on the parallel port. Playing back to the original software the responses obtained for the relevant signalling. There was a DOS (Disk Operating System) driver that had to be installed on the machine in support of its operation. The dongle breaker thing worked, though not with the package that it was obtained for and not the advanced Sentinel key.

Engineering software was extremely expensive, mainly as the libraries for everything generally had to be developed from scratch. Graphics drivers were a nightmare and Windows drivers a pain the rear end (well Windows hasn't changed, at least some things stay the same).

Thanks for the entertaining blog posts, as you say 'back in the day' http://dictionary.cambridge.org/dictionary/english/back-in-the-day'.

[SimonR]

Dongles are still one of several valid ways for licensing software. I currently use a USB key for one of my development systems because its the best fit for the way I have to work.

[apis]

I don't see why a dongle would add any extra protection from crackers. A cracker will try to break the weakest link, that could be the dongle if it's simplistic, but typically it will be by circumventing the part of the software that does the check.  Dongle or not, there have to be some part of the software that handles the copyright section and that can always be circumvented. Dongles always seemed like gimmicks to me and I assumed that is why they went away.

[Fungus]

Dongle or not, there have to be some part of the software that handles the copyright section and that can always be circumvented. Dongles always seemed like gimmicks to me and I assumed that is why they went away.

Cracking isn't always easy though.

eg. You can do the check differently on different CPUs (hash the CPU ID). It will run perfectly on the cracker's machine but when he releases the crack he'll get 50% of people saying the crack doesn't work on theirs. Do it four different ways and that number rises to 75%. You need to crack it four times on four different machines.

Or checksum the part of the program that checks the dongle to see if it's been tampered with. Start doing this three weeks after installation (when the user has some data files) and you'll probably end up with a sale when the crack stops working.

Time delays are your friend. Do some checks only after the program has been running for a couple of hours or after a certain number of edit operations. A cracker will hate you for that. He doesn't want to sit using your software for hours/weeks to see if he found every last check.

Obviously nothing is crack-proof. But with a bit of deviousness and imagination you can make it take many months. For a game that's nearly as good as crack-proof.

It helps to have cracked a few programs yourself (ahem).

https://www.vg247.com/2016/01/08/latest-pc-drm-tech-too-hard-to-crack-no-more-cracked-games-in-two-years-says-cracking-group/

[sleemanj]

I am quite sure that if a New Zealander is called a sheep shagger to his face that there are an ample supply of jokes against Australians

Absolutely, if an Australian calls me a Sheep Shagger, I will call him, an Australian.  That alone is insult enough!

[Brumby]

Steady on ............

[EEVblog]

Using the same term in reference to humans, is quite direct and has a bit more to it.
It's a phrase I don't use.

It's a joke, get over it. Too much of that taking offence crap around these days.
It's also a term of endearment, like Septic Tank, or Pommy Bastard.

[ez24]

I agree with the last word in the letter - "bullshit"

Funny the author would end up with this word.


Bulls can eat a lot of stuff so their shit can contain a lot of different material, like the letter, but it is still bullshit.

Disclaimer: I did not read the letter (I fast forwarded the video) but it did look like bullshit (to me).

I suggest Dave stay away from these bullshitters.

[Brumby]

Using the same term in reference to humans, is quite direct and has a bit more to it.
It's a phrase I don't use.

It's a joke, get over it. Too much of that taking offence crap around these days.
It's also a term of endearment, like Septic Tank, or Pommy Bastard.

I'm happy to take the piss out of those on the other side of the ditch as much as the next guy (to a point) - but that phrase is one I would personally avoid.  That's all.

There's a lot more we share with each other than the rest of the world.  ANZAC for instance.

[apis]

Dongle or not, there have to be some part of the software that handles the copyright section and that can always be circumvented. Dongles always seemed like gimmicks to me and I assumed that is why they went away.

Cracking isn't always easy though.

eg. You can do the check differently on different CPUs (hash the CPU ID). It will run perfectly on the cracker's machine but when he releases the crack he'll get 50% of people saying the crack doesn't work on theirs. Do it four different ways and that number rises to 75%. You need to crack it four times on four different machines.

Or checksum the part of the program that checks the dongle to see if it's been tampered with. Start doing this three weeks after installation (when the user has some data files) and you'll probably end up with a sale when the crack stops working.

Time delays are your friend. Do some checks only after the program has been running for a couple of hours or after a certain number of edit operations. A cracker will hate you for that. He doesn't want to sit using your software for hours/weeks to see if he found every last check.

Obviously nothing is crack-proof. But with a bit of deviousness and imagination you can make it take many months. For a game that's nearly as good as crack-proof.

It helps to have cracked a few programs yourself (ahem).

https://www.vg247.com/2016/01/08/latest-pc-drm-tech-too-hard-to-crack-no-more-cracked-games-in-two-years-says-cracking-group/

Hmm, interesting, didn't know they were having problems now. We will see if it lasts. I didn't mean to imply it is easy, but a hardware-dongle should not make it harder.

[Smokey]

This is one of the most accessible explanations I've seen of modern type anti-reverse engineering measures.  It's a super interesting read.
http://www.oklabs.net/skype-reverse-engineering-the-long-journey/

[ngonthier]

Sorry but that "micro circuit" is not what was used in the Apollo AGC.

Hi Jr460,

actually I have not said this specific circuit and package was used in the Apollo guidance computer (AGC). In my letter I wrote that "MIT team that designed the Apollo guidance computer (ACG) selected the Fairchild Micro Logic RTL dual NOR as the main building block for ..."

I think Dave simply made a short cut

The first problem with that package that was sent in was both the block I and block II machines were made with 3 input NOR gates, not 2 input gates.

Yes, I agree with you. What I sent to Dave is a dual DUAL input NOR, not the dual TRIPLE inputs NOR used on the AGC. Still  the uL 914 is part of the same Micro Logic (uL) family.

The block II on the other hand went to flat pack dual 3 input NOR gate, and took 2800 of those.

Again, I agree with you. I didn't said the AGC used a TO package. They used ceramic flat pack.

A few other things that need to be corrected, it was not 16bit machine, it was 15bit, but memory had a 16th parity bit.

Yes, I took the liberty to say it was a 16 bits architecture , but yes technically speadking it is a 15 bits machine 


Thanks for your comments! If you are interested by the AGC and you want a real deep dive into the architecture and operation of this machine, I recommend the book " The Apollo guidance computer, architecture and operation" from Frank O'Brian at Springer.


Cheers

Nicolas

[SimonR]

I thought I saw that it said it was the same family as well. As far as I know it was the only family available at anyway.

I can also recommend Frank O'Brians book, its a really good read especially if you want to pick fault.

The AGC was not 15bit plus Parity it was 15bit plus SIGN. The sign result of a calculation is stored in this bit in order to detect overflow as there is no carry flag.