Tuesday, July 31, 2007

'$100 laptop' production begins

Hardware suppliers have been given the green light to ramp-up production of all of the components needed to build millions of the low-cost machines.
Previously, the organisation behind the scheme said that it required orders for 3m laptops to make production viable.
The first machines should be ready to put into the hands of children in developing countries in October 2007.

Monday, July 30, 2007

Three films they messed up

I know you can never make a film that mirrors a book exactly - and in a sense why would you want to? They are different mediums but by converting a book to a screenplay there should be an expectation that you at least carry across some of the ideas and convictions of the original author.

  • Starship Troopers was a book by Robert A. Heinlein which I devoured as a teenager and was very taken with some of the ideas - truly unique ideas (a bit like the first time you saw The Matrix?). However - seeing the film was a real let-down. It's what you'd have got if you gave a fifteen year-old $150 million to make a film.

  • I, Robot by Isaac Asimov was another favourite from my teenage years - how did they manage to get it so wrong?

  • A Clockwork Orange - as an undergraduate I found some of Burgess's ideas about language very compelling. Like Orwell he makes the point that because you essentially think in your mother tongue if you let your language degrade so does your power of thought. In the case of Orwell's 1984 the degradation of language is used for political control but in the case of Clockwork Orange it leads to moral decay.
    Now I know Kubrick is a genius and all but when I first saw this movie (knowing the book very well) I thought that he'd never actually read it - at best having read the O-Level notes or maybe a bloke in the pub had given him a half-cut summary. The sequence where Alex imagines himself as a Roman Centurion just made me think of glossy 70's pr0n and I found none of the subtleties or nuances of the book.

Wednesday, July 25, 2007

Corning Announces Breakthrough Optical Fibre Technology

Corning's breakthrough is based on a nanoStructures optical fibre design that allows the cabled fibre to be bent around very tight corners with virtually no signal loss. These improved attributes will enable telecommunications carriers to economically offer true high-speed Internet, voice and HDTV services to virtually all commercial and residential (apartment and condominium) buildings. Current optical fibre installations lose signal strength and effectiveness when bent around corners and routed through a building, making it difficult and expensive to run fibre all the way to customers' homes.

Hmm - one to watch out for. Hopefully not the big let-down that plastic-fibre was!

Tuesday, July 24, 2007

Korg M1 battery replacement and patch re-load

My middle boy Daniel plays keyboard and drums (though not at the same time - that would be clever!) - his keyboard is an inherited Korg M1 - back in the late eighties/early nineties it was the multi-timbrel keyboard of choice for many bands but is now a bit long in the tooth. Still the keyboard is nice with good touch-sensitivity and after-touch. The AI synthesis that it employs is great for piano and organ patches and you strings are pretty lush.
Recently it started flagging up that the internal battery was going flat and of course we ignored it - eventually it lost all it's patches, combination sounds and sequences and without spending half an hour trying to program a better sound it produced a plinky-plonky piano that nobody wanted to hear! So - I scored me a £10 USB-MIDI cable off eBay and set about finding the SysEX files to re-load. Terry Little's Korg site is fantastic - he has a walk-through with photos for replacing the CR2032 button cell and links to the original Korg factory settings. I use BankEditor (which is a MIDI librarian specifically for Korg M1 & K3s) - it even comes with the factory Combi, Programmes and Drum kits.
For some reason MidiOX - my MIDI utility of choice - failed to write anything back to the M1 even though it could extract SysEX dumps. Anyhow - Dan is back is the land of the Hammond B3......!

Sunday, July 22, 2007

Diagnosing faulty fibre splices

I go to lots of facilities where other engineers have run in fibre and the story is often the same - broadcast engineer who knows a bit about fibre and knows a firm who'll pre-make him tight buffered cable. Now - aside from the fact that tight-buffered cable for installation is never optimal why do they always choose the cheapest patch-cord cable rather than robust cable?

Anyhow - after a chance comment made by the instructor at Tyco last Tuesday I realised you can light up a fibre with a visible laser and the light will spill out at a bad splice. How often have I puzzled over which end of a loose-tube cable has the bad splice? The tester tells you you're loosing 5dBs of optical power but without a Fluke DTX-1800 (with the OTDM module - an extra £4k on the £5k basic!) you can never tell which splice to to blame.
The picture shows a bad splice (but not that bad - it was only loosing 5.5dBs - so would be fine on 2gig and probably fine on 4gig, but not optimal). The little red dot in the middle of the splice protector was a lot clearer than this 'phone-photo shows.

The Maplin keyfob laser pointer was the best fiver I spent this weekend. I just had two 12-hours days of fibre action and it saved a lot of time.

Friday, July 20, 2007

British Telecom tom-foolery!

Here's a question - has anyone ever had a pleasant experience at the hand of BT tech support? Here is a previous post with another example of their poor customer service.
Anyhow - a few weeks ago I'd set up an audio streaming server for a (non-technical) friend. All was well with him edge-serving the stream to another server that had a shed-load of bandwidth. Now, he has BT broadband and they offered him a free upgrade from his 2meg aDSL to their basic business offering (which is an eight-meg circuit). He jumped, but on the day that they upgraded him his connection went dead - well, the crappy little USB modem claimed it was connected but no traffic would flow. When I got to it I discovered that I could ping IP addresses on the internet but no DNS instantiation was going on. So - I called BT and after the usual 'is your anti-virus up to date' etc. I got to speak to a tech who seemed to know what he was talking about. Eventually he did admit that the fault must be in the BT network and gave me a fault reference number. Why he bothered is anyone's guess because when I'd gone another support rep called back and despite my friend giving him the fault reference number they persuaded my friend the fault must be with his PC!
Anyways - I returned a couple of evenings later with a Draytek Vigor 2600 router (it's the standard router we provide to clients for our remote access support). It has a superb status page and will happily detect correct Virtual Path and Channel Identifiers (VPI and VCI figures). guess what - when BT goes from two to eight megs you need to update the VCI to 38 - why do none of their tech's know this?
Anyhow - it's kind of interesting that with a VCI figure of 37 only some protocols worked - I think the difference is between UDP/IP and ICMP - DNS uses (by default) UDP to do look-ups. I should have forced the PC to do DNS look-up over TCP and seen if it made a difference.

Tuesday, July 17, 2007

cat6a, cat7 and all that 10gig stuff!

I spent a day at Tyco in Stanmore doing some training on the newest types of ten gigabit network cables. Since there is no ratified standard for ethernet at this data rate (even though both Intel and Cisco have products) everyone is referring to it with different terminology. The Germans refer to the cable as cat7, the Americans as cat6a (the 'a' is augmented) and Tyco (who seem to have the biggest portfolio so far) as XG-10gig cable.
We spent the morning going over the physics of it all - the new cable is a 600Mhz channel and by QAM64 and OFDM (which I blogged about recently) signal processing techniques they can get ten gigabits per sec down one hundred metres of cable. If you use earlier cat5e or cat6 cable you are pretty much limited to sub-30m lengths.
The differences in cable and termination are sufficiently marked with respect to vanilla cat6 as to require different tools and techniques and everything is specified (even down to the sub-50N of force you can apply when pulling it into ducts). They seem to have woken up to the fact that relying on common-mode rejection as the only means of noise reduction is flawed and consequently this new cable is double-screened - the pairs are individually shielded and there is an overall screen. This is why the cable is also referred to as PIMF (pairs in metal foil).
Reasons for differences;

  • Near-end cross talk is dramatically reduced by virtue of the new ends and termination tool. When properly terminated the twisted pair and shield is maintained to within a couple of millimeters of the pin on the connector. You could never achieve this with traditional punch-down methods.

  • Alien cross-talk is minimised by the over-shield - cat5e and cat6 never really enjoyed this advantage.

  • Inter-pair cross-talk is minimised by the foil shield around each of the pairs.
There is no RJ45 plug that can be crimped on - you can only buy pre-made patch cords. Panel to panel wiring is the only termination type permitted on site.
This has to be the future of data-centre wiring - we're currently doing a job that involved 600-odd circuits like this (and it's in a visual-effects company), however - I never imagined I'd have gigabit at home and it can only be a couple of years before ten-gig ethernet is ubiquitous.

Friday, July 13, 2007


Scanimate is an analog computer system that was built by the Computer Image Corporation of Denver, Colorado in the late sixties and early seventies. In all only eight machines were ever produced. It was used on many famous jobs over the years, and many of the people that were involved with its development, operation, and care and feeding have gone on to do significant things in a variety of places all over the world. Dave Seig's website is a real treat and a reminder of how innovative engineers had to be before digital framestores were possible. Many thanks to my old mucker Saul Budd for putting me on to this.
It reminded me of the BBC Anchor caption machine that was an electronic analogue video caption generator. By generating shaped wipes (in much the same way as an analogue vision mixer works by using line and field rate waveforms to create circular, square, etc. shaped wipes) with variable voltage offsets to position them the machine was able to make letter shapes and hence words (and even whole lines of text!). Being an analogue machine it drifted and so the kerning between letters would change and even the size of characters changed over the duration of the programme (requiring the operator to keep his eyes on things!).
Now when I started at the Beeb in the eighties people still commonly referred to electronic caption machines as 'anchor' (the news studios all shared an 'anchor lobby' which at that point is where the Aston 3 operators worked). I never saw a working example but ironically some programmes still used real artwork captions (scanned on Sony DMX3000 cameras).

Thursday, July 12, 2007

Barcodes and all that

One of the neat things my old colleague Ian Staite did was to introduce me to the joys of barcodes! Since we had to keep a tight reign on tape management at Big Brother and Fame Academy we developed some nice templates for printing tape labels with all the salient data carried in a barcode. Code 39 (sometimes called Code 3 from 9) is a discrete barcode. This means that a fixed pattern of bars represents a single character.
Each character is made up of 9 bars - 3 of which are wider than the others. (In this context a bar can be the printed black bar or the white space between the bars.) A single character therefore consists of 5 black bars and 4 white bars.
The ratio of the bar widths can range from 2.2:1 to 3:1. To read a barcode reliably the decoder must be able to differentiate between the wide and narrow bars. In practice it is better to use barcodes close to the 3:1 ratio which allows nearly a 50% barwidth error to occur before ambiguity occurs. The space between each barcode character is called 'The intercharacter gap'. Its width is undefined but is usually equivalent to a narrow white bar.
There are a couple of things to remember when using this barcode fount;
  • Each barcode has to start and stop with an asterisk

  • Don't try and pack too much data in or make the barcode too small - the Lindy hand-scanner I'm using (which just emulates a USB keyboard - it's like someone types in the numeric value of the code very quickly! The software doesn't know it came from a barcode scanner). I've found 120mm wide is the max and 8-point fount-size is the lowest you want to go before the scanner doesn't read it accurately every time. Using those figures you can reliably encode about 25 bytes.
This is for another production company who have asked me to set them up with tape labelling and barcodes.
I also found a great article about data validation in Excel.

Monday, July 09, 2007

Tour De France from the London Eye

The Tour De France started in London and we got to see the start of it from the London Eye - courtesy of Root6. Thanks to Mark for this photo (he was in a different pod) - it's me and my youngest, James.

Sunday, July 08, 2007

Reasons to hate Black Magic, part 3

I have a long and proud tradition of criticising Black Magic Design - much beloved of the FCP crowd their products are built to a price rather than the signal spec. Read some of my previous rantings here and here. This last week I had the pleasure(!) of their new Intensity Pro card - HDMI & analogue component (at 1920x1080) capture. The reason they've launched this card is the slew of HDV camcorders that have an HDMI output. Now - we all know about HDMI's support for HDCP encryption. For most things the HDCP flag is set but no encryption is present. That's the way games consoles work (and foolishly we thought that this card would be good to capture the HD output of a PS3) - BUT, if the card sees even a hint of the HDCP flag it won't capture! Also - the card output is not the usual RGB feed you've expect, but whatever colour space the Quicktime clip is recorded in!

Never mind the quality, feel the width.

When will they start to conform to the specs rather than fobbing you off with "I'm sorry - that's not a supported configuration" - argh!

Wednesday, July 04, 2007

The PAL vertical interval

Our very own Kevin King asked me about the vertical interval in a PAL signal - the above diagram is excellent and has all you need to know. It's taken from a Tektronix training manual from the late eighties by Margaret Craig called Television Measurements - PAL Systems.
Essentially you should bear in mind the following;

  • Active video starts at line 23 - actually line 23 is a half line so the first 26 u-sec is blank - people who don't know about video often notice this!

  • The other half line is the first half of line 623 (end of field 2) - the reason for the two half-lines is to give the line-scan circuit the best chance to make it back to the same point when it starts the new field.

  • There is no half-line at the start of field-2 or the end of field-1

  • Field 1 and Field 2 both end with five equalising pulses and then start the next field with five broad pulses, to be followed by more eq pulses. These are the only lines not to have a colour burst - that's what Bruch Blanking does on older SPGs.
The reason for a lot of this is down to the stability of phase-locked loops constructed from valves rather than transistors - if you have (potentially) unstable oscillators for every waveform (line-drive, field-drive, sub-carrier etc.) then you have to take every effort to make sure nothings changes phase too quickly - hence the half lines, the broad and equalising pulses etc.

Tuesday, July 03, 2007

The futility of re-using old storage

I was over at a facility doing a site survey for a fibre network and the owner/operator told me how he planned to re-deploy his ancient 300gig LanShare storage system as an MP3 storage pool. I did a little mental calculation about the economics of re-using old storage; That model of LanShare consumes a bit less than a kilowatt of power - now I'm assuming he's paying seven or eight pence for a Kw/h and so by doing the maths (and bearing in mind the cost of a 300 gig drive - £69.00 inc. VAT today) he's burning that much electricity every three weeks! Even setting aside the cost of administrating ANY Avid storage (and the licensing considerations, needing client connection software etc. etc.) there is no good reason to re-use an old LanShare or Unity.
I had the same argument a few years ago with someone who wanted to re-use a 10x9gig fibre array - the cost of a fibre HBA to allow him to re-use it in a PC was many times the cost of a 120gig drive (and I didn't even do the power calculation) - it's NEVER worth it.

A facility I worked at in the mid-nineties had Paltex edit controllers (of a mid-eighties vintage!). Anyhow - back then the EPROMs containing the software were only 32 Kbytes big. Eventually the system software got to requiring 64 Kbytes of space and so they had to produce an updated system board that actually had the A16 line wired. Imagine my horror when (to avoid the £800 upgrade cost) I had to manually wire (with kynar wire) the most-significant address line on old 32K-capable system boards! By the time I'd finished a couple of them they looked like birds' nests and were about as stable as Charles Manson!
Incidentally - the kilobyte is an obsolete measurement of memory size. Back in the eighties skilled programmers could pack a lot of functionality into a 'K' - I saw a chess program that played a very respectable opening coded in that much space. Nowadays (when programmers are called developers and bolt objects together rather than writing computer code) the megabyte will soon the an obsolete term.
The megahertz is an obsolete term that refers to the speed of old microprocessors' clocks....