* Posts by Steve Todd

2025 posts • joined 19 Sep 2007

Xiaomi greets MediaTek with a handshake, Qualcomm feels awkward

Steve Todd
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Re: I can't wait

You only have a 1 gig data allowance? That's a bit on the mean side. Saying that mobile data usage tends to be very bursty. You want fast response to your requests, then to power your radio down. Most folks these days will struggle to get through more than a couple of gig of data in a month.

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Mondeo Man turns into mutant electrical beauty: Ford Mondeo Hybrid

Steve Todd
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No government grant for hybrids. You need a pure electric or plug in hybrid for that.

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Tesla's battery put in the shade by current and cheaper kit

Steve Todd
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Re: Back of an envelope calculations

What kind of house do you live in where 300kg on a wall is a structural integrity issue? On plasterboard partition walls, yes. On structural brick? They can support the roof and upper floors without problems. 300kg, distributed allong a wall, isn't a serious load.

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Steve Todd
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Re: Back of an envelope calculations

There are a number of good reasons why you"d not want to use lead acid (beyond just the weight).

Firstly, if you want to get more than a few hundred cycles out of them you need to limit yourself to not more than 50% discharge (30% if you want 10 years life out of them).

Secondly you lose power during charging lead acid (ignoring the losses in the charger circuitry) to the tune of about 15%

Thirdly you need a three stage charging circuit, and for the top 20% you need to trickle charge otherwise you knacker your battery life (as does NOT giving it a 100% charge).

The cost of a lead acid system may be lower in the short term, but it's more over the 10+ year lifespan we're talking about and produces some fairly noxious ewaste into the bargain.

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SpaceX Dragon crew capsule in 'CHUTE ABORT drama – don't panic, no one died

Steve Todd
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Re: Not on Shuttle-

It was one of the extra safety measures they brought in following the Challenger disaster IIRC. It was doubtful that it would do any good, but the idea was not to smash the 'nauts against the side of the airlock as the wind caught them on the way out.

As the solid boosters and external fuel tanks could all be jettisoned I think the idea was that the shuttle was the emergency escape capsule. That didn't work out too well though.

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Tesla Powerwall: not much cheaper and also a bit wimpier than existing batteries

Steve Todd
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Re: Not adding up

You really want 72V+ of high current DC power open to the air in your house? A tad dangerous don't you think? Conversely have you worked out the current you'd need to deliver 2kW @ 12V, then the thickness of the wire needed to carry this?

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Steve Todd
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Re: Not adding up

Checking online, yes 115Ah is achievable for that kind of price. There are still three issues I can see. Firstly cooling. You can't just strap them into a closed box the exact size of the pack, plus you need management electronics. Secondly lifespan. The cells I looked at all seem to be rated at about 500 cycles, to get 10 years or more use out of them you need to be quite conservative over your use and underrate the capacity (use at least 6 or 7 of them). Thirdly weight. They were over 25kg each, by the time you get 6 strapped together that's going to need some fairly hefty brackets to hold them on the wall.

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Steve Todd
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Re: Not adding up

I'd check your math there. Five lead acid batteries giving 7kWh would work out at 116Ah @12V. A regular car battery is something like 40-50Ah

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WHY can't Silicon Valley create breakable non-breakable encryption, cry US politicians

Steve Todd
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Re: COINTELPRO

AES was the result of an international competition and international scrutiny. The winning algorithm was created by Belgian cryptographers.

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Citroën C4 Cactus BlueHDi: A funky urban crossover

Steve Todd
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Re: On mirrors on the left and the right

You need side mirrors on both sides for reverse parking to start with (seeing how much clearance you have on each side), nothing to do with left/right hand drive. Producing versions of a model for both markets (and right hand drive isn't unique to the UK, Japan and Australia are both right hand drive to start with, and Japan in particular has a pretty successful automobile industry) is problematic. We have a Skoda (VW underpinnings) that has a difficult to use hand break because of conversion.

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RADIOACTIVE WWII aircraft carrier FOUND OFF CALIFORNIA

Steve Todd
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In California?

In deep water off the coast does not equate to "In Califonia"

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Easy ... easy ... Aw CRAP! SpaceX rocket ALMOST lands on ocean hoverbase

Steve Todd
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Re: Meh

The first stage must land about 200 miles down range of the launch site (it both lifts the second stage upward and imparts some of the orbital velocity). Because returning back to the launch site would need too much fuel mass (velocity would need to be reversed and then it would need to be flown back along its track) and they launch from the coast (to avoid dropping exploding rockets on enhabited areas) the barge was the solution.

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Kia Soul EV: Nifty Korean 'leccy hatchback has heart and Seoul

Steve Todd
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Re: CO2? @hiker - math error

Without checking your other numbers, you get 115.7g/mile or 72.3g/km @3.5 miles/kW. You'll be hard pressed to match 72.3 using an IC engine, and you don't deposit other pollutants in the middle of urban areas while driving either.

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Google research bods hope to LICK BATTERY life limits – report

Steve Todd
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Re: Another vapour-ware

You need to work in Wh not mAh, otherwise comparison is meaningless. Your NiMh cell is 1.2V nominal, so stores 3.6Wh max. A lithium 18650 cell can easily store 3000mAh, but at a nominal 3.7V, so 11.1Wh, or a little over 3 times the storage capacity.

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Embarcadero’s cross-platform XE8 RAD Studio targets iOS 8, IoT

Steve Todd
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Re: were't even close to C++ performance

No, the compiler option is to skip array bounds checking. This makes a small improvement to performance (at the cost of adding risk) and is something you can do in Delphi also. What you can't do is force VB to use raw memory arrays, the lack of which is where the real overhead is.

I used to make a living programming VB (every version since VB3) and can guarantee that if you needed raw performance then VB was not the answer. It was however fast enough for a lot of work, and the visual design GUI was very productive which is what made it useful.

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Steve Todd
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Re: were't even close to C++ performance

That's a bit of a pointless distinction if most computationally heavy work is using arrays and you can't force the VB compiler to give you fast arrays. The link you give doesn't help your case BTW, if you work your way past all the compiler switch info you find this quote : "At The Mandelbrot Set (International) Limited (TMS), when we really need speed-and after we've exhausted all the algorithmic alternatives-we turn to the C compiler.", so they admit that VB isn't as fast as C by a noticeable fraction.

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Steve Todd
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Re: were't even close to C++ performance

Until you reach Visual Studio .NET the backend compiler is nowhere near the same. In .NET it is, but it's running on a virtual processor so isn't a native binary or running at binary speed. Performance proof? How about this http://www.sythe.org/programming-general/383073-benchmark-test-vb6-vc6-delphi6-java.html

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Steve Todd
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Re: native code compilation in VB

I'm not sure I see your point here. Most high level languages rely on library code, even or especially C/C++. Statically linking that code into the source is the most portable option, but takes most space. Putting it in a DLL saves space if you have multiple applications/DLLs that use it. VB goes a step further and requires the library(s) to be registered under COM in order to work. So unless the VB RTL has been installed a VB EXE will fail, and even then it's not even close to C++ performance.

A Delphi program on the other hand can run without installing stuff and at close to C++ performance, but with the ease of VB style visual development. The fact that it can work in a dynamically linked environment is a bonus.

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Steve Todd
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Re: native code compilation in VB

Not really true either. VB 5 and onwards may have been able to compile, but they still needed the support of a run-time library and the EXEs were't even close to C++ performance. Delphi could generate stand-alone EXEs with close to the same levels of performance.

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Popular crypto app uses single-byte XOR and nowt else, hacker says

Steve Todd
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Re: Get a grip!

AES is a standard part of the ARMv8-A instruction set. Before then it was non-standard and implemented by only some manufacturers.

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Microsoft dumps ARM for Atom with cut-price Surface 3 fondleslab

Steve Todd
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Re: So close..

Erm, I think that was the point. If they were to throw in the pen and keyboard for that price he'd be interested. Get it?

Since PC World are flogging convertable machines (full keyboard, detachable tablet/screen) for £250 then I think he's on the high side.

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Mono Magic: Photography, Breaking Bad style

Steve Todd
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Re: Foveon

You're assuming that Foveon sensors are perfect also. They are not. There's a lot of crosstalk between Red, Green and Blue. The blue channel contains large red and green components. Green contains a lot of red etc. It's this crosstalk, plus manufacturing variations, that cause the colour inaccuracies that I was talking about.

Modern CFAs deliberately introduce some crosstalk between adjacent colours themselves, so each photodiode gives more spacial information, plus the filters are formed into lenses to increase the amount of light hitting each photodiode. The result is higher light sensitivity and a more predictable colour response than Foveon types.

Use your Sigma and be happy, just remember that there are reasons that most of the photographic world uses CFAs and are happy with them. (And no, I don't work for a CFA manufacturer, nor any photographic company. Nor do I employ other accounts for down/up voting)

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Steve Todd
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Re: Foveon

In photography there's no arguing against someone who says "I like it". It's a personal preference and you can't say someone doesn't have it. What you can do is to point out when their reasons given for liking something are incorrect. I've never come across colour Moire patterns on a conventional DSLR, but far more objectionable are chromatic aberrations and lens distortion. Both of those can be corrected out by a decent RAW converter, but the only converter available for Sigma Foveon cameras is lacking in those facilities, is slow and badly written.

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Steve Todd
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Re: Foveon

Firstly that's a 180 degree about face in your position, you claimed that Foveon sensors made all the difference between film and digital.

Secondly he IS wrong. Take a digital image, add the right contrast, saturation and curves, add grain effect noise and you'd be hard pushed to spot the difference between film and digital. You can take sublime photos on a cell phone, never mind a modern DSLR or film camera.

Thirdly the lack of an anti-alias filter is a cheat in any analogue to digital conversion (sound, images or whatever) as any detail above 1/2 the sampling frequency will produce false artefacts. Go look up Nyquist's limit, this explains the problem. The lack of the filter produces false lines and repeats when you get close to or above the limit on the Sigma. You don't get blotchy colour, but it's still wrong.

Distortions and noise are easy to add. Not so much to remove. A good camera system concentrates on getting as close to perfect as possible, and lets you do what you want with the images afterwards. There are many great photographers of the past who relied on the printing process and what they added there to lift their work above the ordinary. Digital makes this faster and easier.

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Steve Todd
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Re: It is techno-Luddism

@Nigel

Unless you like the smell of the chemicals (which I found moderately unpleasant) and have the space for a dedicated darkroom then you're better off learning how to use RAW format on a DSLR (or on of the better bridge cameras). This gives you full control over converting the data from the sensor into a displayable image with nothing needed but a PC.

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Steve Todd
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Re: Foveon

I started using film cameras over 35 years ago. I've used medium format and 35mm, B&W (which I did my own darkroom work for) and colour. I've been involved in digital photography since the days of the Kodak DC1, have had a DSLR since the Cannon 20D and have seen and compared Foveon images with conventional Bayer. Foveon sensors still need an anti-aliasing filter to prevent Moiré effects, but look less ugly than colour Moiré that you get from Bayer so Sigma cheat and don't use one. The result is a sharp looking image (with Moiré if you look) but poor colour discrimination (it tends to confuse reds and orange for example). Reduce the size of a Bayer image by about 20-30% along an axis (with sharpening) and it looks at least as good, and you still have more pixels.

The only manufacturer who tried Foveon (Sigma) seems to have given up the battle (last updated over 2 years ago IIRC), and their cameras were slow, clunky and unable to handle above 400 ISO equivalent.

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Steve Todd
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Re: Foveon

Bayer filters aren't the problem that you seem to think. They mimic the way in which the human eye works, with less sensitivity to colour data than intensity. Foveon sensors are worse at colour discrimation and accuracy, plus they don't even come close to matching Bayer type sensors for detail (divide Bayer pixels by about 1.6 to get equivalent Foveon (real, not counting R, G and B separately) pixels.

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Apple's portable power podule patent promises paroxysms of fanboi joy

Steve Todd
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Re: I don't get it

Patents are for "a method". The patent isn't on fuel cells, they've been around for some time. This patent appears to be for a method where the mobile device charges AND communicates with the fuel cell pack at the same time, allowing it control over charging and access to info like the fuel level.

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China's BYD ramps up 'leccycar battery production in challenge to Tesla

Steve Todd
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Re: Battery life is an issue on the Tesla?

LiFePo - Lithium Iron Phosphorus.

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Steve Todd
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Battery life is an issue on the Tesla?

Last thing I heard they were exceeding their target of 80% of original capacity after 8 years of use.

Lithium iron cells have the advantage of being safer, with no tendency towards thermal runaway. They have the distinct disadvantage of significantly lower energy density, so you need a bigger, heavier battery pack for the same range.

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BBC: We'll give FREE subpar-Raspberry-Pis to a million Brit schoolkids

Steve Todd
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FAIL

Re: Ha @codejunky

Scientific bias isn't banned by their charter. Political bias is. I can't say that I like their stance on a number of scientific issues, but that doesn't make them wrong or bad. My taxes pay for scientific research that is biased against my views too, that doesn't mean that I should be able to opt out of paying for them.

These machines will be used at school. No matter how poor a child is their school will have rooms full of PCs that they can use these on. Chances are their local library will also have machines able to program them. This is not an equality issue.

The Pi on the other hand requires the machine, an SD card, a PSU, a HDMI cable, a HDMI capable TV or monitor, a keyboard and a mouse. Minimum that's going to add up to 10x the cost of this device and there are far fewer kids who could use it at home.

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Steve Todd
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Re: What can you do with a 74HC00?

Letting them loose on a simple CPLD might be fun. A MAX V 570 for example should give them enough logic to build a CPU for about £5

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Steve Todd
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Re: Ha @codejunky

The BBC isn't allowed to be biased against a particular party. That doesn't mean that individual programs cant be biased, but as a whole their output must be unbiased. They tend to show bias and take a stance on particular issues (global warming for example), but then so does any news agency you care to mention.

As to existing educational projects, think of this as an intro to those who will move on to the Pi, Arduino, mbed etc. The device is small, simple and cheap. It's there to introduce the fundamentals of computer hardware and programming. Its for kids who have just started secondary school, and you don't want to throw them in at the level of how to program a GUI at that age, you want to get them hooked on the ideas and wanting to take things further.

Costs? The BBC isn't paying for the hardware. The partner companies are. All the BBC are doing is creating some educational programs to teach kids how to use them. That's definitely in their remit.

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Steve Todd
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Re: Ha @codejunky

You missed the bits about "Inform and Educate". Being at arms length from the government its a damned site better than any state funded news organisation, and normally better than ITV news. It's also hard to argue against its role in education, which is what this whole thread is about.

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Steve Todd
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Re: Ha @codejunky

Listen out for that whooshing noise. It's the sound of the point going over your head. Many people in the country don't like Trident, but the government decided to fund it in the public good so their taxes go towards paying for it.

Likewise the BBC is held to be a public good (entertainment is just one of the three legs it is built on). Because of that the public has to pay for it, like it or not. Democracy is like that. Don't like it? Move county.

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Steve Todd
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There's a little more info

over here http://www.bbc.co.uk/mediacentre/mediapacks/makeitdigital/micro-bit

Looking at the picture and backers list I'd guess it was an entry level ARM M0 connected to an nRF24L01+ radio chip and a simple LED matrix. Less than £5 to build in that volume would be my guess

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Apple Watch: Wait a minute! This puny wrist-puter costs 17 GRAND?!

Steve Todd
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Re: Overpriced?

Not it you want it to still work you don't. The oil on the bearings has a limited lifespan to start with, it needs to be stripped down completely, cleaned, re-lubricated, re-assembled and re-calibrated unless all you want is an expensive wrist ornament.

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Steve Todd
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Re: Overpriced?

Rolex watches need an expensive service every 2 years and, even brand new, they are way less accurate than even a cheap quartz watch. They are every bit as much about being a status symbol as one of these Apple watches.

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Steve Todd
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Re: Worth it's weight in Gold.... @Metrognome

Plating? The whole point about the Edition version is it's machined from solid 18K Gold alloy (an alloy that Apple have toughened up compared to standard 18K Gold). If they sell it in the UK I'm assuming it will have to be hallmarked. We're talking 1,000s in raw materials before they start the machining process.

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Intel SoCs it to 'em with new D: Tiny but powerful

Steve Todd
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Re: Cheaper PCs/Servers was how x86 got a look in

Unfortunately for you and Intel that number is closer to 1/2 than 1/10, and the newly anounced A72 core reduces that lead significantly. The other, rather large factor that you're ignoring is that companies can get ARM based chips made to specification, with precisely the onboard IO support that they require rather than Intel's one size fits all approach. This makes the complete system cheaper by more than the cost of the CPU. I do hope you aren't resting your pension hopes on Intel.

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Steve Todd
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Cheaper PCs/Servers was how x86 got a look in

Mainframes were displaced by Mini Computers. Mini Computers were displaced by workstations. Workstations were displaced by x86. Why do you insist that x86 is immune?

These Xeons are 45W parts. Current technology ARM 64 chips draw about 4-5W for a 4 core CPU with onboard IO. 40 physical cores on the same energy budget as one 8 core Xeon?

All they need do to take a large chunk of market share is to be fast enough, have software support and be cheaper.

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Elon Musk insists Gigafactory's ALL GO as China charging fears hit Tesla shares

Steve Todd
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Re: China

Have you done the sums? You could run a domestic 3kW air conditioning unit at 100% continuously from the Tesla battery for 28 hours. In practice you'd get longer than that as it won't run at 100% continuously and you don't need a 3kW plant for a cabin the size of a car.

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UK spaceport, phase two: Now where do we PUT the bleeding thing?

Steve Todd
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Re: two options

There is Machrihanish airfield, that was certified for use by the Space Shuttle (as an abort site) and has a 10,000ft long runway.

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Steve Todd
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Re: North East

Or maybe Durham Tees Valley airport? Due to management incompetence it seems to have 2 or 3 scheduled flights per day, but RADAR/ATC left over from when it was an RAF reserve base so it handles most of the traffic up to Newcastle and down to Leeds.

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Nokia boss smashes net neutrality activists

Steve Todd
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@Donn Bly

You're dead wrong there. If an ISP can provide a decent technical justification why, for example, Bit Torrent traffic is being slowed, and it is only being slowed enough to cut congestion, then there isn't a problem. Comcast's justification and amount of throttling didn't meet that standard. VOIP on the other hand is low bandwidth and predictable in its nature. You'd need a LOT of connections before VOIP flooded a network, and even POTS has connection limits.

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Steve Todd
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He seems to have failed to understand

What net neutrality is. It does allow for the prioritisation of packets. What it doesn't allow is PAID prioritisation (and that includes prioritising companies in which the ISP has a financial interest above similar services). If VOIP packets get priority then ALL VOIP packets are treated equal, no matter where they came from.

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NO ONE is making money from YouTube, even Google – report

Steve Todd
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Apple did this when? They offered to sell tunes on the iTunes store for a fixed 30% fee. Labels are free to withdraw from this deal, set the price band of their music etc. What they did, that the Labels didn't like, was to unbundle tracks. It turns out that the buying public did like this and the Labels made lots of money this way.

Next they offered the Labels money for the right to provide cloud storage for tracks that users had already bought or obtained from elsewhere. Free money for doing nothing.

Finally they have been working on deals for streaming on demand. I've not heard of them making other sales conditional on being involved in this program (which would probably get them in trouble for abusing their position in the market).

The only ones ripping off the artists are the Labels.

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Qualcomm bungs ARM's beefy 64-bit A72s into new mobe brains

Steve Todd
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Re: @JamesTQuirk

You seem to be trying to change the subject. Non of the A80 boards that I have seen are much less than £100 each, but they would need to cost less than £10 each to be competitive with a desktop GPU in terms of FLOPS/£.

Your original point was that the Qualcomm chips (also ARM based) wouldn't sell. My point was that they were much faster than the A80 you were holding up as an example of Chinese technology that was going to kill it, and that they were aimed at a different market segment (the A80 isn't really targeted at cell phones). Because of this I expect them to sell in huge quantities inside of Chinese cellphones (the Chinese don't really care where they get their parts from, just how they effect the saleability of their devices).

You also seem to be trying to make out that my attitude makes me a Wintel stooge. What? Saying that desktop is more powerful than mobile (demonstrably true) and that the Chinese don't make the best ARM chips makes me a Wintel fan? Time to take your head out of your arse.

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