When I was small I have memories of my grandma and my parents owning one of these phones, not that they had much choice of course since it wasn’t until the early 80s that other companies were allowed to make phones in the UK; before that it was the good old GPO’s job to rent one out to you. I took mine to bits to fix the dial, it kept sticking, and while taking it apart I took some photos which are attached to links throughout this post. Read on, this is more than a bunch of photos…
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… as it was 20 years ago.

While wandering around a local car boot sale this book caught my eye. I quite like the old science and computing books from the 80s and 90s. There’s a certain style to them that doesn’t exist any more. They’re books I used to read from the library or have bought for me at Christmas. Books aimed at children, but books that assume the children reading them aren’t stupid and can cope with complicated words.

I also like the hand drawn images. No computer rendered images in these books. The World of Science is the usual affair telling us all about atoms, space, magnets and gravity. None of it goes into any particular depth, but it’s enough to make an enquiring mind think “that magnetism stuff… what’s it do, where can I get a magnet from? Dad, buy me that science book on magnets please it can be an early birthday present”. Don’t forget, in 1990 there was no Wikipedia so information wasn’t instantly available, it had to be paid for in books. Yes teenagers… books… you didn’t just fire up Google and type “what is magnetism” into the PC; a time when libraries actually contained more books than computers.

The best part of this book is the Tomorrow’s World section at the back where the book’s authors attempt to predict the future. Yes, there’s the assumption we’ll all be in space in little 2001 style pods, flying cars and the like. And like all books of the era, it totally and utterly fails to predict the popularity of computers or mobile phones. I wonder what blindingly obvious things we’re missing right now…

Here’s a two page scan of that section to read. Click it for a bigger image.

Or, how observant were you and how absorbant was your mind?

Think hard, what’s the furthest back you can remember?

I can remember being at nursery watching TV. Only because the ‘Thames TV‘ logo had a distinctive sound. I can also remember having to go to bed during the middle of the day at nursery, which I used to think was a really stupid idea. We had toast, then we went to bed. I was fine with the toast bit, but the going to sleep? Why? There was still so much Lego to play with!

I can also remember wondering why TV programs said ‘MCMLXXXIV’ at the end of them.

I don’t remember my first day at school though. I remember the day the smelly kid came to school, he cried a lot and we did about the Romans and their under-floor heating.

Sometime last year my old Kenwood hifi amp stopped working due to the speaker cutout relays not working. The speakers would never switch on, making for a fairly useless amplifier.

While my cousin was sorting out his mess before moving to the US he found this old “FAL” brand amplifier. A spot of Googling reveals this was made by a company called “Futuristic Audio Limited” who also seem to make guitar amps. He didn’t want it, I needed an amp, so it came home with me.

Due to its age I noticed quite a lot of noise when trying to adjust the volume so decided today to take it apart and attempt to clean the insides out. I also bought some switch cleaner to spray in the potentiometers.

The insides were very simple. Here is a photo of the main circuitboard which contains nothing but through-hole mounted resistors and capacitors. The most complex electronic components in this are the four transistors bolted to a piece of metal. There are also some large looking capacitors, and an interesting looking network of diodes.

Unfortunately I think cleaning the contacts on the potentiometers and switches might have messed the electrical characteristics of the amp up. Since this isn’t an IC based amp, I have a feeling there’s a fine balance between the components that makes the thing work, and squirting a load of switch cleaner into things has altered this. When I power the amp up, only the left channel works and the volume goes really loud then distorts – all by itself, without me moving the volume knob. I’ll leave it for a few hours to see if the cleaner evaporates off. It’s no great loss if it is broken, the reason I took it apart was because the sound wasn’t correct and the volume kept wandering between left and right speakers, so maybe it’s finally packed in.

Looking at the electronics inside, part of me wonders if it’s repairable.

I use Google Reader to follow quite a lot of websites, blogs and anything else interesting that squirts out an RSS feed. For the curious, here is a list of my favourites. I’m leaving out the well known things like XKCD, Dilbert, Hack-a-day and so on.

• http://uncertaintimes.tumblr.com/ I have no idea what this is about, but it never fails to display interesting and random images at least once a day.
• http://cargocollective.com/learnsomethingeveryday Learn something new, every day. Information presented in nice little cartoon drawings.
• http://www.dadhacker.com/blog/ It’s a sort of programming based blog, written by Landon Dyer who I believe used to work at Atari and Apple back in the day.
• http://www.bytecellar.com/ Interesting writings about old computer systems.
• http://digitaltools.node3000.com/ A tech blog that writes about various fun and often arty things, such as nice Flash games, strange bits of hardware and art installations.
• http://www.trafficengland.co.uk/index.aspx Totally not tech related at all, this site simply tells you all about the state of the UK’s road network. Grab the RSS feed and have your own instant travel update system. If only I could get this in my car and have the relevant reports displayed while I’m driving about.
• http://impossible-world.blogspot.com/ An art blog that shows Escher-style “impossible” drawings.
• http://fcd3.blogspot.com/ A programming blog detailing the creation of a Z-Machine interpreter for Infocom games.

I often find these kinds of sites while browsing around the comment fields of popular websites. It’s fun to click the random links in people’s signatures…

What are your favourite websites to visit? I’m always interested in new things to read.

I’ve been given one of these cameras along with a zoom lens and 55mm prime lens by Amy. I did some research on the web and discovered the camera was the first SLR camera with a pentaprism and dates back to around 1960. I stripped it down and discovered the clever simplicity of totally manual SLR cameras, there’s nothing inside them!

Really nothing, I took the lens off, opened the back, set the shutter to “Bulb” mode and upon pressing the shutter release ended up with a giant 35mm hole going right through the camera. Nothing on this camera is electronic, and it’s so obvious now looking through the lens and twisting the aperture ring to work out how that affects the image.

It’s been cleaned out and loaded with film. I’ve already shot ten “test” shots and will take it for a ride about on my bike tomorrow if it’s not raining. The Asahi Pentax camera is all metal, with a zoom lens that weighs more than my Nikon DSLR body and lens! The lens also has “Made in USSR” stamped on it This is a camera I’d be quite happy dangling from my neck while walking through town – if anyone tried to steal it  I’d just whack them on the head with it

I took a few photos of it, and a few photos looking through the lens. Meta-photography is sort of amusing.

Once I’ve used up the film and found somewhere that can develop it, and assuming the camera doesn’t leak light like a Lomo I should have some nice photos. It’s quite hard guessing the exposure settings by eye, but since I shoot in manual on my DSLR I’m constantly altering the aperture and shutter speeds anyway and I think my guesses should be good.

So the current tech craze is netbooks. First we had tablet PCs, which never took off. Then it was UMPCs which sort of died off when devices like the Nokia N800 and iPod Touch came out. Then the world finally got a grip, realised the Internet was important, that we liked keyboards and big screens and concentrated its effort on making laptops smaller and netbooks took off big time.

Only, go back to 1989 and you’ll see Atari created the Atari Portfolio, then go forwards a few more years and Amstrad came out with the NC200 notebook (really, that’s what it calls itself). And if you’re a bit daft, you can go into Maplin and come out with a Datawind Pocket Surfer, which uses good old GPRS and a proxy in Canada to render popular websites in several shades of off-blue. Using these ancient devices is like watching history slowly being created, with different companies trying to work out what portable computing should be like.

I wonder what future portable computers will be like…

I’ve just ordered a Texas Instruments TI-85 calculator from eBay. I need a real calculator, and I always wanted a TI-85 when doing my GCSEs at school.

I found these fascinating videos showing how vacuum tubes used to be made.

You can find part 2 here.

And if you want to know how tubes work, here’s a series of videos explaining them

Electronics at work Part 1

Electronics at work Part 2

Diodes have two plates. Triodes have three. That’s why they’re called ‘diodes’… I never knew that before.

A month or so ago I ordered a DivIDE board from Papaya Labs. The DivIDE board is an ATA interface for the ZX Spectrum, allowing IDE devices such as hard disks, CDROM drives and Compact Flash cards to be plugged into the Spectrum, which, through a special loader built into the board, allows .Z80, .TAP and .SNA images to be loaded into the Spectrum and run. The .Z80 and .SNA images are simply pushed into the Spectrum and it runs them with no need to reboot. The .TAP files are presented to the Spectrum as real tapes, and after typing ‘LOAD “”‘ they load in exactly as a tape would – only in a few seconds, rather than a few minutes.

This is a long post, with lots of information in, more after the break… Press it, you can watch a YouTube video at the end. More photos of the setup available on my photos website.

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These things are somewhat amazing. With nothing more than a coil of wire, a pencil, razor blade and some random wire it’s possible to construct a crystal radio set. These things are so simple the fact they work at all is like magic.

All it takes is a long piece of wire for an antenna, a ground connection and then some sort of semi-conducting material for a cat’s whisker and you’ve got a radio. ‘Semiconductor’ sounds a bit high tech, so replace that with ’something that mostly conducts electricity, but not that well’. The signals are incredibly weak and tuning is an artform and watch where your hands go or you’ll end up becoming part of the radio!

I built the set from random junk in my house. The purple wire I have on a spool for just such occasions, the razorblade came from my bathroom (no, I’m not Emo ) as did the toilet roll tube. The cork block is actually a sanding block out my toolbox.

The ’set’ is connected to my PC’s soundcard to amplify the signals but even with that I had to turn the volume of my PC right up to the point the speakers were humming with all the stray EM noise my house generates (the washing machine is on at the moment which can’t help things).

I worked out the construction of the radio by looking at a few pictures on the web and then fiddling until things worked. I had problems with the lacquer coating on the thin wire I took from an old hard drive’s read arm assembly. Eventually after some faffing and prodding I had the pencil causing giant bursts of static when it touched the razor blade. The razor blade needs to be “blue”, to do that it needs heating in a flame until it glows red.

And then the coolest thing ever happened… I picked up a football match. I hate football, it bores me to death, but the fact it came from a bunch of crap on my desk was pure magic

If you try to build one of these but it doesn’t work, test all the contacts by prodding them with your fingers. There should be little bursts of static or other noise if you touch stuff. The set is highly sensitive to everything, so if it works sit still and try not to wave your hands about. Seriously, for reasons beyond my understanding I had an excellent signal if I touched my finger to the blue thumbtack, and put a dirty spoon across the wires going to the soundcard plug. Blowing onto the pencil helped too since the contact needs to be “just right” and is utterly random.