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ZX81 QR Codes

QR codes seem to be getting everywhere these days - having just downloaded a QR code reader for my phone, I was keen to find out about how they work. Turns out they're quite simple, and looking at them, it struck me that several of the smaller sizes could be reproduced on the low-resolution display of a ZX81. :) Perhaps Uncle Clive was more visionary than we realised and thought about what people might try with his tiny "computer" in the twenty-first century.

Sinclair helpfully provided a set of mosaic graphics characters, each made up of all the possible combinations of quarters of a square. You can get a maximum of 64 by 44 of these "quarters" displayed on the screen. You can see them on the keyboard...

Having found an online QR code generator, I fed the URL for this blog into it, and it produced a QR code small enough to fit onto a ZX81 screen. Next step was printing it - I then drew a grid over the top, splitting it up into 17x17 ZX81 characters. It was then easy enough (although very time consuming) to map it all to ZX81 graphics symbols, printing the whole lot on screen using 17 lines of BASIC. It all took longer due to some problems with RAMpack wobble about halfway through, which was annoying, but after that I saved it after doing each line. Eventually I finished it...and was pleased to find it worked! Well, sorta.

That's it screen-grabbed running on the EightyOne emulator on my PC. It works instantly with no errors, and I got it right on my first attempt. However, running it on my real ZX81 is more problematic, probably because of the crappy, tiny telly I use as a "monitor". However, a printout from my Alphacom 32 printer worked just fine, despite the dubious print quality. A reasonable quality TV display should make it simple enough to read one of these without too much trouble.

There's no real point to this, of course, but it kept me busy for a while, and it was satisfying to get it right first time, and do something the thirty-year-old ZX81 was NEVER designed for. I suspect the coding process for QR codes is simple enough to make a ZX81-based coding program possible. I might give it a go. :)

Asus Eee 2G Surf

This is probably the newest thing in my old stuff, if that makes sense. It dates from 2008 but things have come a long way since then, and this product was the first of its kind and bit of a pioneer.

I present the Asus Eee 2G Surf.

Asus managed to successfully turn the computing world on its head with these - a tiny, low-spec laptop for basic computing tasks. In a world where everything had been getting more powerful and more expensive all the time, launching a low-spec product like this was a risk, but it somehow worked, and netbooks are now very popular (or at least will be until iPads and the like kill them off).

So...I got one of these back in 2008 almost as soon as they were launched, and it's about the only time I've ever been an early adopter. The model I have has a miniscule 2GB solid-state drive in it, which came with a custom OS based on Xandros Linux. It was very simple and didn't have much in the way of bells and whistles, but it let you get online quickly, and worked for basic office tasks too. All things considered, it was a lovely little thing that's barely bigger than a hardback book and goes in a bag really easily. It's small enough to fit on the fold-out tables in airline-style seats on trains, which is more than can be said for bigger laptops.

I soon ran into some hassles with the OS, though, and Linux netbooks were a short-lived breed. Before long, Asus was producing Eees with 160GB hard drives and Windows XP installed. The OS this shipped with had very poor wifi and networking drivers which made it very hard to go online using my phone. Windows XP, if you strip it down a bit, just about fits in the 2GB space available, but it bloats up to much bigger than that almost instantly and kept filling all the drive making the machine useless. I've subsequently tried various flavours of Linux but all of them were too big to fit on the internal drive, requiring an 8GB SD card in the storage slot. All well and good, but it makes it painfully slow to boot and robs you of using the slot itself.

After much ripping out of hair and a bit of experimentation, I've got the very small (if slightly cheesy) Puppeee Linux running on it (complete with comedy dog noises on bootup) and it seems to like my phone for going online, so that's good.

I want to use it for writing on the move, now that my Psion and Osaris PDAs have become too old and clunky to reliably interface with anything else, and so the dust is getting blown off this now quaintly basic and simple device. As I said, things have come a long way in a short time, so this is now officially "old".


Historic Consumerism

Someone has done the world a vital public service by scanning the entire 1985 Argos catalogue.

It's amazing how much has changed - manual typewriters, anyone? Black and white tellies? Record players? They even have Super 8 film in stock.

Here's a few of my favourite pages.

Disc cameras! And check out those cool reading glasses!

I'm wired for sound.

Very entertaining. :)


I'm enjoying being a ZX81 owner again. Back in the early eighties when I first had one of these, I was hardly a power user and didn't really do much of any use with it - but now, I'm curious to see exactly what you can do with one of these. Given that it's about the most primitive computer you'll come across, I'd like to see how far you can push it.

When the ZX81 first appeared, most people didn't know what they'd actually want a computer for, and they took some convincing that they'd need one. Thing is, most of the software that appeared for it was good as proof-of-concept, but that's about all. For example, there's a name and address database program that you can play online here - but on a real ZX81, it's absolute shite. It stores only 50 addresses, loading them takes at least several minutes, and the searching and sorting are deadly slow. It would be OK if it was thousands of entries, but for fifty, a notebook works better by far.

Anyway, some of the software was vaguely useful, like Vu-Calc, a primitive ancestor of Excel, and I'm about to get Critical Path Analysis from eBay - yes, you can manage a project on a ZX81! This will be fun...

Clive Sinclair once famously boasted that you could run a nuclear power station using a ZX81. I'm not sure if he actually said that, or if it's an urban myth, but it's interesting to think about whether it's really possible. At least in theory, it probably is, given that nuclear power stations have been around since the 1950s, when computers were very rare, very big, very slow and very expensive. The ZX81 was very crap, but maybe it could do the job.

Let's define the job a bit first. When you say "run", Clive, what do you mean? I don't think you could automate every task within a nuclear power station with a ZX81 - that would be far too much and far too risky. But...let's say you want to monitor various temperatures, output voltages, radiation levels etc., and alert staff to things going wrong so they could take action. Would that be do-able?

I suspect it would. If you take one of the ZX81's most complex programs, what it can do is quite impressive given the limitations of the machine. Let's use Psion's Flight Simulation as an example.

I don't know if this is a particularly good flight-sim (graphics-wise obviously it's not), but it seems to work, and handles a lot of complex variables in real-time. It takes input from the user (flaps, power, climb, dive, steering, undercarriage etc), processes all those inputs and provides pretty quick output, all things considered. So...monitoring the nuclear power station requires us to write some software to handle a series of calculations on assorted inputs.

Flight Simulation's inputs are all from the keyboard, natch. The ZX81 is extremely sparse and minimalist as far as plugs and sockets go, so some extra hardware would be needed to get the data from your nuclear power station into the machine. Anyway, turning to the pages of the November 1982 issue of Sinclair User, we're onto something.

Bingo! Eight-channel temperature monitoring for seventy-five quid! Not sure those temperature ranges would be adequate for reactor cores, but I'm sure you could do something to sort that out. It shows you can use a ZX81 for temperature monitoring without too much trouble. I'm guessing that means you can develop suitable A/D converters and software for radiation and smoke detection too. Great! We're almost there!

Next, you'd need a piece of machine code that can process all the inputs and work out the relationships between them, so that if something goes outside safe limits, a warning can be sounded. That shouldn't be too much trouble, but the ZX81 can't produce any sound, so you might have to sentence some poor Homer Simpson-esque schmuck to gaze at a portable telly all day. That's no good - what if he's too busy eating doughnuts to spot a critical message on the screen? Again, turning back to Sinclair User, we have a solution.

Perfect! You could use a nice space-invader sound for reactor meltdown. Looks like a good array of choice is available!

So there you are - you'd need a RAM-pack and maybe a ZX Printer to churn out some graphs now and again. And then you'd be set, sort of. You'd need a beefed-up PSU to handle all that extra hardware, though, or you'd need to worry about ZX81 meltdown more than anything else. Oh, and get plenty of Blu-Tak to avoid RAM-pack-wobble.

That brings me on to a crucial point - you may be able to carry out assorted monitoring and warning functions in a nuclear power station with a ZX81, but for goodness sake, don't just use one. One false move and it would crash, and you'd need to spend ten minutes loading the software back in from tape. That's no good in a safety-critical environment, is it?!? I think you'd need at least three, running two at a time, and having the third as a back-up, so you could cycle through the machines and avoid them being used too much and overheating. Plus, if you have a spare machine around, you can enjoy a quick game of 3D Monster Maze during your tea breaks.

So there you are! I think Clive was right! I just hope they didn't use any of the Soviet-bloc Spectrum clones at Chernobyl.


Call for submissions

All being well, I shall soon be the proud owner of a thermal printer for my ancient and laughably primitive ZX81 home computer. I am going to make a zine using just this technology, which will be a challenge to say the least.

Working within the strict limitations of this kit, I'm very keen to get submissions from people for this zine. The only characters and symbols available on the ZX81 are these:

That's right - no lower case, only a limited range of punctuation, and some very blocky graphic symbols. I'm going to produce the zine by printing a series of screen dumps, and the screen consists of 20 printable lines of 32 characters each.

So...if you're interested in using these very basic building blocks to produce what I hope will be a very interesting zine, do get in touch. If you can write an article properly formatted to use the screen layout described above, and that completely fills one or more screens, let me know. If you can produce it on a real ZX81, even better, but I won't hold you to that! I'm willing to re-type submissions on my own machine. :) I'm particularly interested in anyone who can make pretty pictures using these symbols and characters.

Hope to hear from some of you soon, and hopefully the zine will appear shortly, if I don't suffer from too much RAM-pack wobble while I'm producing it.


Spreadsheets 1982-stylee!

Since getting my ZX81, I've been on a software acquisition spree. There's loads of it on eBay, mostly at cheap prices, and today I got Vu-Calc in the post. It's another Psion product, and it's a spreadsheet (albeit a rather cut-down one).

See, with the wonders of technology, you can play about with it online. I'd always known about the Spectrum version of this program, but I never knew the ZX81 version existed. So...how does it compare to Excel?

It's not bad, actually! For the ZX81, this is a rather complex beast. It can do most of the simple things a spreadsheet can do, but it does have some very serious limitations.

  • Maximum sheet size is 26x36 cells.
  • Only one sheet at a time, of course!
  • No colour, no graphing, no ability to print.
  • No resizing of cells.
  • Only a limited range of mathematical functions available for formulae, and any mistakes that produce a nonsensical result will make the program crash.
  • As far as I can tell, getting a formula to work on a cell that contains another formula makes it crash as well.
  • Calculations on even just a couple of cells at a time take ages, making the screen go blank for several seconds.

All that aside, this is a brave attempt to get the ZX81 to do something more than play bad games, and it's something that could have been genuinely useful to a lot of people. Spreadsheets were killer applications back in the day, and this is one that pushes the ZX81 a long way. Given that hardly anyone had used a spreadsheet in 1982, this was probably quite revolutionary.

In its favour, the user interface is fairly good, and navigating around the sheet is pretty quick. The previous alternative to using something like this was a pencil and paper, so it was a big step forward.

I'm tempted to try some ZX81 Office projects. What shall I use my spreadsheet for? Give me some ideas and I'll see how it compares with Excel. Vu-File is next on the list, I think.

Word processing on the ZX81 is a lot more challenging, given its very limited character set. There are no lower-case letters, and only a small range of punctuation marks. Still, Tasman Software produced Tasword for the ZX81, which was brave of them, and it seems to work. I've only played with it on an emulator, though, and attempts to download the file and convert it into a tape for my real ZX81 have thus far failed. Tasword is one I'm really keen to get hold of.

To top it all, though, I really want an Alphacom 32 printer. If I get one of those, it's ZX81 zine-making time!


ZX81 Heaven

When I set this thing up, one of the key things I was keen to include was some vintage computing. It's very easy to emulate an ancient computer on a PC these days, but it can't beat the hands-on fun of using the real thing. I have a particular soft spot for Sinclair machines, as they were among the first machines I used. I got a ZX81 for my ninth birthday in 1983, and later on got a Spectrum, and this kept me happy for years.

So...I recently posted a WANTED message on my local Freecycle group, and was offered some ZX81 kit. I was very impressed when I went to collect it - a boxed ZX81 in good condition with PSU and all leads, a 16K RAM pack (essential if you want to do anything useful with it), manual and six software cassettes. I got it home excitedly, plugged it all in, and...was disappointed to discover that ZX81s don't like to co-operate with modern flatscreen TVs.

I couldn't get either of the TVs in my house to co-operate, although one of them displayed a picture for a split second that was enough to show me the ZX81 worked. They're notoriously unreliable and fragile, so it was pretty miraculous to get one that seemed to be fully functional. As using a ZX81 on a giant flatscreen seemed wrong anyway, I got hold of a very, very small 5" black and white CRT analogue TV on eBay, which seemed perfect. Apparently, the ZX81's TV output is very crude and dirty, with timing all over the place, and CRTs can cope with this, but flatscreens can't.

Once the thing arrived, I plugged it all in and was delighted to find that it all worked just fine. The next step was loading software. This was always a huge pain in the arse - the ZX81 was notorious for being really awkward and difficult regarding tape loading and saving. Yes, tapes - there were never any disk systems for the ZX81, so you had to use a cassette recorder. That's another bit of kit on the endangered species list, so I looked around for alternatives. I found a program that will convert downloadable files for emulators into MP3 files, so I put 3D Monster Maze on my iPod and attempted to get it to load.

No joy.

Next step was the stereo in my living room, but it lives more or less permanently in one place that made it an ergonomic nightmare to load/save with. But...it did work, and loaded a fair few programs off my tapes with no hassle at all. Having found that tapes nearly thirty years old actually worked, I decided to invest in a proper retro-style tape recorder, and was pleased to find that Sony still make one that meets the spec, and looks the part as well. The design hasn't changed since 1995. :) So, armed with one of these, I had a complete retro-style computer setup.

The TV is pretty tiny and a nice match for the compact ZX81 itself. The tape recorder looks huge in comparison. :)

So...what's it like to use? Actually, it's better than I remember! This thing is laughably primitive, having only a tiny, tiny fraction of the computing power of even a mobile phone these days. Everything it does is painfully slow and it crashes if you look too hard at it. But, despite all of that, it's enormous fun to play with.

The completely flat touch-sensitive keyboard is actually OK, not being any worse than a typical modern touchscreen device. Tape loading and saving is OK-ish in terms of reliability, most tapes loading first time. And some of the games actually aren't bad! 3D Monster Maze rocks, as per usual. Playing it as God intended is great fun.

One of the games included was Space Raiders, which has Bomber on the reverse. This involves attacking skyscrapers with bombs and missiles before your plane crashes into it, which is all a bit Al-Qaeda-ish, but this was written in very innocent pre-9/11 days.

Space Raiders and Bomber are actually surprisingly fast, showing what you can do with some well-written machine code. Note that the games were published by Psion, who wrote loads of software for Sinclair machines before getting into the PDA market. Finally, a shot of the manual as well, which is a lovely piece of retro-futuristic design.

Watch out for more on this - I'm really chuffed with this little thing, and I want to see how far I can stretch it. I'll leave you with a demonstration of what's possible, though - here is a demo video of a prototype interface that allows high resolution graphics, 32K of RAM and instant loading of software from SD cards! There's a guy developing this as we speak, and it looks like a stunning piece of kit. He's almost ready to mass-produce it, and it overcomes just about all the serious flaws in the machine. Games load in a second, not four minutes! This is a real ZX81, doing things you'd never think possible.

The Old and the Ancient

I recently wrote about my love for the Psion Series 5, but sadly since making that post, my Psion has gone the way almost of them go in the end - broken due to hinge and screen cable problems. It's an enormous weakness in the design. I immediately went online to source a replacement, but they were all too pricey. :( I didn't want a Revo as it doesn't have a CF slot or replaceable batteries, so I had a look at a well-known (but quite hard to find) Psion clone - the Oregon Osaris. I got one for peanuts on eBay.

In lots of ways, it's functionally identical to the Psion machines, but has a few important differences. It only has basic beeps for sound, so can't handle recordings or lifelike sounds like the Psion. The screen is also smaller, with a much lower resolution of 320x200, opposed to the Psion's 640x240. This barely matters for the built-in software, which works very much like the Series 5, but just looks a bit blockier. It's bit of a pain for other software, though, which often doesn't quite fit on the screen properly.

The CF slot door is a pain in the arse to close properly and doesn't always work, making it fail to recognise the disk being present sometimes. The quality of the thing doesn't always feel up to Psion standards, although the hinge is a VAST improvement and feels much more solid.

So...I've been using it for three or four weeks now, and it's working just fine. A bit cheap and cheerful, but it works and does everything I need it to do.

Anyway - last night I got around to installing a Spectrum emulator. The Spectrum is a childhood favourite for me, and you can expect some future Fun With Old Stuff entries to follow on that front. The emulator actually works better on the Osaris than it does on the Series 5, because the screen resolution is closer to that of a real Spectrum, and it displays rather nicely. You'll have to excuse the crappy quality of the photos that follow, but you'll get the idea.

Spectrum 128 boot screen on the Osaris

I'm actually getting a ZX81 on Tuesday, courtesy of Freecycle. I'm not sure yet if it'll work, but if it does, one of the games I shall be sure to play on it will be 3D Monster Maze. This is, as far as most people know, the first ever first-person 3D game to be written for a home computer, and as such it's impossible to over-state how revolutionary it is - especially when you consider how crappy the ZX81 actually is. :) It was an incredible achievement. Just to get me in the mood, I thought I'd play it via the joys of emulation. You can't get a ZX81 emulator for the Osaris, but someone has thoughtfully dealt with that, by porting the original game to the Spectrum with virtually no changes. It works by emulating as much of the ZX81 as it needs to run the original code. So - here for your delight and delectation, the world's first 3D game, on an Osaris, emulating a Speccy, emulating a ZX81. :)

Roll up, roll up!

In the maze

Argh! Run!


Such larks. Gaming history on a pocket gadget that's old, but still ahead of it's time. :) I'll leave you with this great video of someone playing the game on a real ZX81, an experience I hope to recreate myself very soon.

Special Guest Feature: Printing Presses

I felt honoured when funwitholdstuff invited me to do a guest journal here! I’m bicyclegasoline, and I have been brought up with a right mixture of old and new technology – spare moments as a child would be spent either on the latest Apple Mac (which my Dad needed for his work) or looking at the old BBC computers in the garage! My brothers loved old audio equipment, and my Dad would do slideshows and get old reel to reel tapes out on family occasions. But the biggest secret in my parent’s semi detached family house? The garage, which is full of printing presses, type, ink, and anything you could possibly want to print at home!

The main feature? An Arab Platen Printing Press, which you can see on the right of the picture. A large machine, which I have marvelled at since a young age, and which I think all the family are still mesmerised by (although my Mum would be grateful if it took up slightly less room!!) My Dad inherited it from his old school, where he used it to help print the school newspaper. It still has some larger jobs, such as wedding invitations within the family, but generally it is now used for pleasure.

When I learnt of funwitholdstuff’s fascination with this almost forgotten world of printing presses, I knew precisely how I was making his Birthday card this year! Let me talk you through how we did it...

Thankfully, my Dad has been through most of his collection of type, and created a little book showing all the different fonts. These are just what he has collected over the years, so unlike on a computer, just because you have a font in one size, doesn’t mean you have it in another size, or even have all the letters!!

I chose “Thorne Shaded” in size 36 (which happens to be the only size he has in this font!)

It so happened that there was only one “Y”, and we all know “HAPPY BIRTHDAY” has two... So we did the words separately, and used separate colours. We began by arranging the word “BIRTHDAY” in a composing stick as seen below:

We started with “BIRTHDAY” as we were using red ink, and doing “HAPPY” in black, and it’s best to use coloured ink first. The word “BIRTHDAY” was then transferred to a chase (a metal frame which holds the type) on an imposing block, which is simply a big smooth slab. The type has to be held in place with furniture (blocks of metal, almost like “padding”) and quoins, which are adjusted to apply force to the furniture, so the type is firmly in place.

Following this, the chase is bravely lifted, and you just hope the type is securely held! In this case, paint stripper was needed to remove old ink, white spirit to clean it, and a snake block to smooth the type to give a smooth print.

We smeared red ink onto a glass plate, and used a rubber roller until it was warmed up and rolling smoothly.

We used the rubber roller to roll the ink onto the plate of the press, and set the press in motion to get the press’ polyurethane rollers inked up. To begin the press in motion, the brake is removed, the wheel given a slight push, and then the foot pedal allows you to control the speed slightly.

When the rollers were well inked, the chase containing the type was mounted into the press, and held in by tightening the clamps. The type is then inked using the rollers.

The fiddliest bit comes next, as the paper and the type are lined up. We simply glued blocks to the packing, and rested the paper on it; adjusted the bars and elastic bands which prevent the paper getting stuck to the block when they meet; and started a trial and error process!

We set the press in motion, let the rollers run over the ink a couple of times to make sure the type is well inked, and when ready to print the impression lever is pushed forward to bring the paper and the type together to make an impression. When printing presses were in common use, the aim was to have as little impression as possible, so as to disguise that it was printed on a press. Nowadays? A very different story, with people wanting deeper impressions, as a contrast from the everyday printing we now experience!
It took a few tries, but here is the final “BIRTHDAY” imprint...

Then starts the clean up process!! Lots and lots of white spirit, rags and newspaper, a heck of a job! Only to make it dirty again with the black ink printing the word “HAPPY”, using the same process as above!

The final result is, in my opinion, impressive. And more than worth the time and labour that goes into it.


I'm very inclined to agree - it was a fine birthday card! Thanks! - funwitholdstuff

APS - Film's Last Hurrah

Remember APS? No, I didn't think you did. :)

APS, full name Advanced Photo System, branded Advantix by Kodak, is without doubt the last format ever invented for film-based photography. After extensive research and development, it appeared in 1996 - and (almost) died very shortly afterwards. It arrived just a few years too late - digital photography killed it off pretty quickly.

The Wikipedia entry gives you a pretty good background. Unlike all the consumer film formats that came before it - 126, 110 and the truly appalling Disc - APS had some nifty features that made it rather good. Sadly, it's one of those things that everyone took against and it wasn't really very successful.

I've owned a Nikon Pronea 600i, and I currently have a Nikon Pronea S - these are APS SLR cameras, and they totally rock. Honest. I'm not insane.

Because no-one seems to want them, APS cameras are awesomely cheap. I like them for the following reasons:
  • The aspect ratio of a full negative is 16:9, i.e. the pictures are the same shape as the monitor I'm using right now, and the same as widescreen TVs. Why the hell are there no 16:9 DSLRs?!? What a retrograde step!
  • A good APS camera will record a load of exposure information magnetically on the film. This can be encoded as EXIF data if you get your pictures scanned at the time of processing. Nifty analogue/digital hybrid. :)
  • The digital info on the negs helps get really good results every time, even using seriously outdated film.
  • The cameras are small and fun to use.

Here's a few of my own APS images. Enjoy! (click to enlarge)

G8 protests, London, April 2009

Camden Market

Danebury Hill Fort

London Eye at night

Further APS musings here and here.