* Posts by techmind

76 publicly visible posts • joined 16 Jun 2009


Microsoft fixes the thing it broke via another dose of out-of-band patching to deal with BSOD printing problems


Does the same bug/patch/KBxxxxx

also cause a white band to be printed over bitmap prints from paint.net, when using the "type 3" printer-drivers?

(A new issue with an old printer, which only happened since the most recent Windows Update)

High-resolution display output or Wi-Fi: It seems you can only choose one on Raspberry Pi 4


30 years ago, when we had analogue radios...

The people of the day soon learned that radios operated in the proximity of various computers and other electrical devices would cause interference, which would manifest as various buzzes, whistles, whines and other audible noise. You soon learned what sort of sound of interference was caused by what sort of appliance.

Despite the claims of the proponents of digital comms, these interference issues haven't gone away - they've just been hidden. Your digital wireless device works... until it randomly drops out - and you're left with no clue as to what the source of the problem is.

A £150-£200 software defined radio (such as the SDRplay RSP2) in the right hands can be very useful for identifying interference sources below 2GHz.

(The £20 RTL dongles while they demonstrate the principles of SDR have so much self-interference and poor image rejection that they are not very useful.)

T-Mobile US hacked, Monero wallet app infected, public info records on 1.2bn people leak from database...


Understatement of the year

"Due to the sheer amount of personal information included, combined with the complexities identifying the data owner, this has the potential raise questions on the effectiveness of our current privacy and breach notification laws"

- last few lines of the linked https://www.dataviper.io/ story.

The genie has long-since left the bottle.

It goes without saying that the risks of building a database of that size far exceed any legitimate societal* benefit.

But without a seismic shift in how we process and share data, there's nothing can be done to prevent people building these. Laws are practically worthless.

*societal (as opposed to a handful of marketeers' narrow interests)

Boffins blow hot and cold over li-ion battery that can cut leccy car recharging to '10 mins'


Re: Charge or just swap the batteries?

Like this...?


Bad news from science land: Fast-charging li-ion batteries may be quick to top up, but they're also quick to die


Re: Sony

When you plug in the Sony phone to charge at bedtime, it tells you when it plans to charge it by. You have the option to do a non-optimised faster charge if you have an exceptionally early morning - or you can turn off the optimised charging altogether if your lifestyle is that chaotic.

My 7-8 year old Sony laptop has a battery saver mode where (when enabled) it only charges the battery to "80%" rather than 100%. If the machine is mostly a desktop-replacement, this is little loss, but means the battery is still in excellent condition 7-8 years on.

I recall with Li-Ion the *time* that they are maintained at close to full-charge is a significant factor in causing long-term degradation. So never charging above 80%, or only "topping them off" just before you're going to use the capacity makes sense.

Li-Ion batteries designed for fast-charge (e.g. for cordless power-tools) tend to use a Li-Fe-Po (added iron, the Fe), which makes them more tolerant of fast charge and discharge (and less likely to spontaneously combust), but at the expense of something like 20% less capacity by weight or volume.

**All engineering is a compromise**

Dear Britain's mast-fearing Nimbys: Do you want your phone to work or not?


O2 and Vodafone already do extensive mast-sharing in the UK

O2 and Vodafone have extensive mast-sharing agreements for 4G in the UK.

See: https://pedroc.co.uk/content/vodafone-o2-beacon-1-and-2

In my area (Cambridge / South Cambridgeshire) you can even see (check on a phone) that O2 and Vodafone signals from the same site broadcast the same eNodeB identifiers...

Mini computer flingers go after a slice of the high street retail Pi


Re: Can I buy more than one Pi Zero?

I think I recall a "one per customer" limit flagged on the shelf for Pi zeros. What's this all about?

Why are sat-nav walking directions always so hopeless?


Cycling instructions from Google can also be mad


Now try changing the direction. There's a 2.8mile off-road route, but it'll send you on an 8 mile trip via the A14 (practically a motorway). Depending on the time of day, this requested route will even take you there and back between two junctions on the A14! Yes, the starting point is contrived because I know it's next to a bridleway (though it does involve crossing various bits on the A14 on foot - this being an officially signposted path).

Oi, clickbait cop bot, jam this in your neural net: Hot new AI threatens to DESTROY web journos


Re: Therein lies the problem - its not the headline..

Destination page...

- More than 50% ads by surface area

- Average reading-age score of any textual content less than 10-years-old

Keep your hands on the f*cking wheel! New Tesla update like being taught to drive by your dad



"On an 'A' road drive today in dry, clear weather using Autopilot on a stretch of straight, clear, flat well marked road at 40mph"

It's one thing using Autopilot on a motorway, but on a small A-road with junctions and cyclists....

Does the Tesla even have the technology to detect pedal-cyclists?

I think I'd better get a move on with fitting a radar retro-reflector to my bicycle.

Autonomous vehicle claims are just a load of hot air… and here's why


Google is doing some impressive stuff...

This TED talk is from 2015

"How Google Driverless Cars See the World"


It's 15 minutes, and gets interesting about half way through.

Really makes the point that on busy multi-lane roads and junctions, being aware of, and anticipating the movements of, everyone else is key.

Uber breaks self-driving car record: First robo-ride to kill a pedestrian


"Emerged from the shadows"

In the video the pedestrian/cyclist-walker certainly does "appear from nowhere". That said, the video does seem to crush the blacks a bit. While in general, the high contrast of night driving does make for difficult imaging (and seeing), I wonder if you'd been there in person, the shadows would have seemed quite as dark as on the video?

While I suspect the camera gamma-curve could have been more appropriate, I also wonder whether the headlamp beams were overly-dipped, or could have had a better profile.

In the UK our headlamps spill a lot to the left (because we drive on the left) and would have picked out the pedestrian at the side of the road before they entered the line of traffic. In the States of course, their lights would be configured the other way.

It seems fairly clear that the woman with the bike made an error of judgement; it feels like the car should have been able to do some more though...

Europe is living in the past (by nearly six minutes) thanks to Serbia and Kosovo


Not quite as it seems

I saw this story elsewhere earlier in the week, and gave it some thought then.

Normally in a synchronous power grid the instantaneous frequency deviation indicates the mismatch between demand and supply (it runs fast if over-supply, or slow if under-supply). There's also a general agreement to make the daily cycles add up over 24 hours to keep clocks in step.

It seems to me that allowing the cycles to run short over a period of days and weeks is a conscious (nod-nod wink-wink) decision of the operators of the power grid in order to make a *protest* (to raise it up the political agenda) rather than any direct technical consequence of the allegedly "stolen" power.

Presumably the electrical grid companies themselves have very limited legal options to pursue in other jurisdictions, so need to get political (governmental) wheels in motion to sort things out.

Power games...

RIP... almost: Brit high street gadget shack Maplin Electronics


Re: >> it was a mere pamphlet

Yes, it was the beginning of the end when they stopped putting the pinouts and other useful information in the catologues - they stopped that before the Internet went mainstream.

And they've reduced their range so much that they could no longer be a one-stop-shop for electronics projects of any complexity ... and once you start having to look elsewhere for a few parts ... well you get the rest elsewhere too.

I've been fortunate being able to order from RS and Farnell for private projects through work, but I understand they're much more open to this now anyway.

Then again, I can't imagine either the RS or Farnell website is particularly easy for younger/less-experienced hobbyists to find some of the things they need - even with almost 20 years "professional" experience I sometimes find it frustratingly difficult to find some basic "hobbyist" electronics staple because I don't know the magic name of it.

Watford Electronics used to have an interesting proposition they sold a considerable range of electronics basics, listed, with prices, in many columns, on about 2 sides of A4 in 6pt text! But while the hobbyists were queuing for the counter service (regularly half an hour or more on a Saturday) for their £15-£20 of small stuff ... the parents or siblings would be eyeing up or playing with the computers and accessories ... with £300 - £500 price tags.

One-third of mobile users receive patchy to no indoor coverage


And things could be improved with better phone software

I have good indoor 2G coverage, and very weak 3G and 4G, all on Vodafone. The phone software would rather hold on to a 3/4G signal (a miss incoming calls) than revert to 2G - and indoors/at-home it can use WiFi for high speed data anyway. Annoying.

Footie ballsup: Petition kicks off to fix 'geometrically impossible' street signs


Re: Metric please


John Finnemore Celsius vs Fahrenheit sketch :-)

(Finnemore is brilliant!)

Outage at EE wrecks voice calls across the UK


Obviously spoofed SMS

Yeah, I received one on Orange, claiming to be from WhatsApp - the old "you need to pay a 99p subscription scam". Apparently this scam was rife in June. But you'd've thought it'd be possible to generically block 'em.

Report estimates cost of disruption to GPS in UK would be £1bn per day


I haven't seen the gov report, but

(Maybe I should at least skim the report. Maybe we all should.)

What we don't know are all the non-obvious (non-navigation) uses which have got baked into applications over the years:

- train doors' safety systems - unverified, but I was told that on Southern Trains the doors can only be released by the driver/guard at stations (as determined by GPS), and that if there isn't a GPS signal (at some covered stations) then it requires manual over-ride

- precision timing, to synchronise radio-networks such as mobile-phone base-stations, and single-frequency-network digital TV and DAB radio transmissions.

Google to give 6 months' warning for 2018 Chrome adblockalypse – report


Re: Price per page view ...

No seriously.

If the price to pay to not see ads was comparable to the average ad-revenue earned for each page-view (i.e. around 1/10th cent), then (as long as Google made it easy to set up an account with them, and they then dealt with the micropayments, and gave me some generic options for maximum to pay, or maximum before asking) I'd be very happy with that.

In fact I even suggested the idea to Google - they're the obvious people to implement such a system, at least for their own ad-network.

The radio environment is noisy – so use the noise as a carrier for signals



1. You're relying on ambient signals that can't be guaranteed to be present in all usage locations at sufficient signal strength

2. You're inherently 'corrupting' the original signal, which is going to add some degree of 'noise' to the original service (which may impair the FM audio or degrade the TV or phone BER) within some proximity of your back-scatter device

3. You may save power on the 'transmitting' (or information-sending) device, but you'll need a much more expensive, sophisticated, and power-hungry receiver to decode the back-scattered signals than if you had a regular transmission in the first place.

Interesting ideas to play with in the lab, but I don't see it being practical in the real world.

'I thought my daughter clicked on ransomware – it was the damn Windows 10 installer'


Re: Slow checking for updates... (on Win7 systems)

Mine too.

It's getting the list of updates in the first place which takes forever (sometimes a few days) - though sometimes they can be reluctant to start downloading too. Never had this problem before Win10 was lurking in the wings.

I wonder if it has to do with M$ update servers being overloaded...?

Notable that away from patch-Tuesdays, other updates such as Windows Defender are found and install without trouble.

India orders 770 million LED light bulbs, prices drop 83 per cent


Re: Have they finally solved strobing?

I too have one (Philips, non-dimmable) LED GU10 lamp - and it has 100% depth 100Hz modulation (flicker). You are not alone. I see this too. It makes my stairs and banisters strobe horribly.

Unfortunately neither the packaging or the manufacturers' websites tell you anything about flicker before you buy...

Google to deep six dodgy download buttons


What took them so long?

Dodgy "download" button-ads have been a widely acknowledged blight on the web for years.

As a website owner, I actually removed Google ad panes completely from pages of mine which offer downloads of applets I've written, because I was worried users would be misled by the dodgy download button-ads (which were more prominent than my own links) and I didn't want the reputational damage.

In the last few days I've been seeing "driver update (recommended)" ads overlaying youtube videos.

Sort it out!

How to solve a Rubik's Cube in five seconds


Re: Algorithm./ Technique

I don't know how it counts officially, but a few years ago I did download a very nice Java applet which, given a few 10's of seconds, would calculate a sequence of 20 moves or less to solve any cube position. Probably this site: http://kociemba.org/cube.htm


Algorithm./ Technique

Although, as mentioned, it is proved that you can solve a cube in a maximum of 20 moves, it takes a modern desktop computer more than 4.904 seconds to do the calculation (though in cube solving the timing only starts when you make your first move - you're allowed to look and ponder it first).

As I understand it, speed-solvers use a subset of more memorable moves which more typically take about 40 moves in practice - and these methods are far easier and more effective than the books/methods published in the early 1980's e.g. by Patrick Bossert or the math prof's booket from that era.

Google engineer names and shames dodgy USB Type-C cable makers


Watch out for iron wires too

I discovered some months back that a surprising number of mouse and HDMI cables stick to a magnet (and cut them open and found it applies to the inner conductors by themselves too). This is truly strange, as you'd expect them to be copper (which isn't magnetic).

Are the Chinese using iron wire or nickel plating or something weird, to save money on copper? That'll increase the resistance too.

Want longer battery life? Avoid the New York Times and The Grauniad


Inefficient bloated code increases power consumption - who'da thought it!

"Software developer Santeri Paavolainen says the code powering today's websites is taxing browsers so much, it's having a significant impact on power consumption."

It's a common observation that visiting certain websites or running particular applications causes the fan to rev up.

I got out of the habit, but for a long time (probably owing to my small-time developer mindset) I always used to keep a task-Manager running in the bar. It's revealing to see when that processor usage start to rise (and processor usage is likely a reasonable proxy for power consumption.)

Spamquake subsides: less than half of email is now processed pork


Last week maybe

I did see a marked lull in spam last week (or maybe for 10 days), but since Sunday I think it's back to normal service :-( Maybe the chief spammer just took a summer vacation.

It's 2015 and ATMs don't know when a daughterboard is breaking them


Re: Beer Tokens

Lloyds Bank were very happy to provide me with a card without NFC. I just walked into my branch and asked; a few days later it arrived.

EU VAT law could kill thousands of online businesses


Absolutely daft.

My other target for regulations which should be totally ripped up as they impose a massive burden on small businesses is the ridiculous system of Commodity Codes which have to be applied to all goods imported/exported for business purposes ... even when its just a one-off box of almost miscellaneous bits worth £50 which are potential parts of some prototype. The commodity codes are used to look up the level of import duties which apply. If you're a small business developing new industrial/consumer/medical equipment for people, it can easily take an hour or more looking up these wretched codes for every item you send - with the ever-present threat that the items will get delayed in customs (and delay the project) if you've not classified it correctly.


But these go into absurd levels of detail for some items, and very general for others.

For example, there's a special classification for

"Coil choke with:

- an inductance of 4,7 μH (± 20 %),

- a DC resistance of not more than 0,1 Ohms,

- an insulation resistance of 100 MOhms or more at 500 V (DC) for use in the manufacture of LCD and LED module power boards"

I kid you not: https://www.gov.uk/trade-tariff/commodities/8504509540



Solenoid coil with

- a power consumption of not more than 6 W,

- an insulation resistance of more than 100 M ohms, and

- an insert hole of 11,4 mm or more, but not more than 11,8 mm





Opto-electronic circuit comprising one or more light-emitting diodes (LEDs), whether or not equipped with an integrated driving circuit, and one photodiode with amplifier circuit, whether or not with an integrated logic gate arrays circuit or one or more light-emitting diodes and at least 2 photodiodes with an amplifier circuit, whether or not with an integrated logic gate arrays circuit or other integrated circuits, contained in a housing"


It's total insanity!

Patch Windows boxes NOW – unless you want to be owned by a web page or network packet


Secure Channel bug - does this affect XP ?

Or XP sp3 ?

Or is XP too old?

How the FLAC do I tell MP3s from lossless audio?


Train yourself

As stated before, MP3 defines a data-stream and the general approaches to generate it. The exact behaviour/performance is dependent on the psycho-acoustic model used by the encoder. Two 128kbps encodes of the same source material by different encoders may sound different.

The lossy compression of MP3 is analogous to the lossy compression of JPEG/MPEG for images/video. Some types of source material are much harder to compress successfullyat low bitrates than others, and the artifacts will be correspondingly more visible (audible).

Your Sennheisser CX300 earbuds will really muddy the sound compared to studio headphones - try Sony MDR-7506.

If you don't know what the MP3 artifacts you'd be listening for, take one piece of source material, and compress it variously to 256kbps, 192k, 128k, 96k, 64k. On any clean source material that hasn't been mastered to digital mush (and dynamic-range-compressed to within 0.5dB of its life) in the first place, the artifacts at 64k should be glaringly apparent. As a very general rule, you'll be listening to for more subtle versions of the same at the higher bitrates. Unless there's something very wrong with the encoder, 256 or 320kbps should sound almost indistinguishable from the source. That's the point!

The early Dire Straits Brothers in Arms CD album (not necessarily more recent remasters/re-releases) had quite a phenomenal clarity. Quite some years ago I made some tests at various bitrates from this material, and it was educational - unfortunately I've now lost both the examples and the original uncompressed material!

NEW Raspberry Pi B+, NOW with - count them - FOUR USB ports


Next major revision should be the PiMaster...

...following the naming convention of the BBC Micro.

Someone's been planning this for a long time...

Vodafone to spend £100m on 150 new Brit phone shops


Sort out the coverage

Vodafone's coverage and performance was excellent where I used to live. One mile up the road however where I now live, and I'm in a coverage-hole - despite being practically line-of-site to a Voda mast 1km away. On first floor occasionally see 4 bars of 3G/HSDPA, but drops to one or none, then falls back to EDGE as soon as try to use it.

Blighty goes retro with 12-sided pound coin


CoinTune must be based on a magnetostrictive material (similar to that used in the kind of security-tags commonly seen in music/DVD shops and DIY stores). This approach is rather neat as it effectively embeds a contact-microphone within the coin, facilitating detailed acoustic analysis without the problems of having to externally contact the coin.

This is completely different to the Royal Mint's iSIS system.



Some power-Googling uncovered this:


Fast-forward to about 6 minutes in...

Basically it seems they are embedding some "optically active" particles throughout the plating (other sources say plating wears off at a rate of about 1µm/year in real use). The Mint is very pleased with themselves for developing techniques of getting this uniform dispersion of particles into the plating, btw.

The particles are detected by shining light on them, and detecting the light that comes back.

Presumably the three levels of security are {overt} basic fluorescence (or phosphorescence) from everyday 365nm UV, and the higher levels {covert} and {forensic} are based on much more specific spectroscopy (or polarisation, or birefringent or geometrical) effects...?

The internet is 'a gift from God' says Pope Francis


Well, I don't know about you, but...

... I feel I've been sensing a rising tide of evil on the internet in the past year. Increasing volumes of virus/trojan-loaded email, Cryptolocker, malicious redirects, fake 'download' buttons (ads), video-ads with sound (what right do they think they have!), email addresses which should only be known to banks now receiving spam/trojans.... Sure this has been bubbling around for many years, but I somehow think a threshold has been crossed.

Even "legit" online advertising (via Google ads, or on Facebook) seems to be getting increasingly murky - to the point where I'm considering removing Google ads from my website (the income has steadily fallen, and I don't wish to be associated with the bad stuff).


Virgin Media spanked by ad watchdog over 'in your neighbourhood' fibs


Yep - they do it to me too

I (and the whole of my estate) keep getting the flyers about how wonderful and fast Virgin Media is. Except that they didn't cable my estate. Even though their cable runs a mere 15metres or so from my house, I am not served. Yet every month they mailshot me to remind me.... grrr.

Should be getting OpenReach's FTTC in the autumn though.

Last 7m non-digital Brits are OUT OF LUCK: I'm OFF, says Baroness Fox


Re: DVLA Site seems fine to me.

Yep. You jump through all the hoops, tell it various bits of info, including move-dates for the past 5 years then it drops you out saying that the photo is too old. So you fill in the paper form, post it to 'em, and a week later they send the newly-addressed license with the perfectly-ok old photo on it. Go figure!

4G LTE: Good for tweets and watching Dr Who. Crap at saving lives


Tetra, being digital...

As I understand it, TETRA is a digital system, therefore any interference WON'T be voices coming out of poorly-shielded HiFi (that'd be some predecessor analogue system). I have a vague recollection that the radio-interface for TETRA was spawned off of early GSM specs, so you'd expect any interference to audio equipment to be in the form of buzzes and beeps not-dissimilar from GSM....

Jailed Romanian hacker repents, invents ATM security scheme


Some machines already employ an intermittent motor on the card insert mechanism

presumably to thwart skimmers.

The card judders as it is absorbed into the slot. This would make readng the magstripe challenging to say the least.

ZX Spectrum cassette player lost? There's an app for that


Well it should work

I've successfully loaded BBC computer programs off a (non-Apple) MP3 player

Good news: Debian 7 is rock solid. Bad news: It's called Wheezy


Any connection to the Raspberry Pi Raspbian "Wheezy" based on Debian?

as title

Drunk driving: No more dangerous than talking on handsfree mobe


Cyclist threat from inattentive drivers

A couple of months ago I saw a cyclist (in a cycle lane) almost rammed from behind by a car doing 35-40mph. The car swerved out into the road only just in time. I was driving in opposite direction at time... just as I was thinking "what happened there" I saw that the approaching driver had a phone in their hands in the middle of the steering wheel - and despite nearly killing the cyclist just moments ago they were STILL fiddling with it.

The Death of Voice: Mobile phone calls now 50 per cent shorter


'Averages' tell you very little ... need a histogram

In my world, the "average" duration of a call may well have halved in the past few years ... mostly because every other call is now some chancer from India trying to help me reclaim my PPI or chase insurance payouts for accidents I haven't had - and 4 times out of 5 it's a silent call anyway.

Big biz, expensive beancounters write UK tax law, says senior MP


The last thing we need...

" the changes include tax breaks for companies that patent their products"

... is more incentives for big companies to file large volumes of largely-vacuous patents.

Too many patents are just a total waste of time to search (and prohibitively expensive to contest) for small companies or individuals trying to develop some true innovation.

Ofcom: You like to make CALLS, yeah? Tell us what you want from mobiles


Simplicity of Billing and visibility of minutes/data-allowance used and remaining

They force direct-debit, paper-free billing - but make it very awkward to get to your bill on the website. Every bill (for the past year at least) should listed on a single web-page, downloadable by a straightforward right-click "save as".

It should also be possible to EASILY sign up to a PDF bill by email, sent automatically, monthly.

Voda and/or Orange require you to jump through multiple hoops to download bills, multiple steps forwards and backwards if you want to get several month's-worth in one go, websites that fail miserably if you start trying to simplify things by spawning multiple tabs, proprietary not-quite-PDF browser-plugins that won't save the document easily, email-it-to-me things that don't work, spurious choices of "full" vs "complete" vs "4-page" bill, click-to-proceed buttons which are located beyond the default border of the popup window (needs resizing even to see the button).... ARRRGGGGHHHHHH!



I second the call to get rid of silly tethering restrictions. If you pay a fair price for the data, it really shouldn't matter whether you're tethering or what device you've popped the SIM card in for this hour or that.

When you've got 3-4 data contracts (different networks; redundancy/backup!), 3 data-dongles, 2 'main' voice phones (different networks), an Android tablet (at present, strictly for data: apps/web on-the-go), and a few more live PAYG phones on-hand (you never know), and a few loose SIM-cards sitting on the Rubiks cube next to the monitor ... it does get a bit confusing remembering what you can do with which.