A bit of geek nostalgia

 Anyone remember this? The Sinclair Z80, one of the first reasonably priced, ready built home computers to be found in the UK. You could either buy one ready built for £99.95, or save a few pounds by buying it as a kit and put it together yourself for just under £80. You needed to be fairly handy with a soldering iron, but that was no problem to me since soldering was part and parcel of my regular job. Of course once I knew it existed, I had to buy one as soon as I could and I was able to afford it because I had been saving up.
Not your usual kind of saving, but a long time back, just before decimalisation of the British currency, I had been keeping all the silver content coins in my change. Before decimalisation, coins had retained the same denominations for well over one hundred years and so there could be coins with all the different heads of past monarchs on them, including the odd Victorian coin. All silver coins were at one time pure silver and right up until 1946, there was some silver content in these coins and all this silver bullion was still circulating as loose change. So like a number of others around that time, I had collected a large set of pre-decimal coins, putting them into year sets and many of these were silver. Ten pounds value of the silver coins I had collected, I had worked out at current silver prices would earn me enough to buy a Z80 kit and have some money left over. I took the coins to a small dealer in London, I had seen advertise, who was offering a good rate of exchange.

 The place I went to turned out to be a really seedy looking shop in the Holloway Road. It was gloomy and unwashed looking inside and I was beginning to have some doubts that I was doing the right thing. The guy behind the counter was not very reassuring either, being just as scruffy as his dingy shop and as I approached the counter a large German shepherd lifted its head and growled menacingly. The guy never said a word the whole time and I offered him the packet of coins, thinking ‘I am going to be seriously ripped off here,’ whilst not quite having the nerve to turn around and walk straight out again. He counted the coins, weighed them and calmly peeled off one hundred pounds from a big roll of notes. I was astounded and very pleased because, despite my qualms, the guy had come across with a good deal and I had what I needed to buy my home computer and even some left over. 

The dog behind the counter in that shop looked a good deal less friendly than this one

The Z80 was not my first computer, a year or so before I had built a PipBug kit computer that I bought second hand from someone who had bought it and then decided they were not really up to the project.

The PipBug computer was about as minimal as you can get. It consisted of just a bare board, no keyboard, no power supply and no usable video output for a monitor. It had a whole 256 bytes of RAM. No that is not a misprint, not Gigabytes, Megabytes, or even kilobytes, there were just 256 memory cells and no means of storing programs you have written when you switched it off. To see what you were doing, it needed a terminal, something used with mainframe and expensive business computers at the time and one of those was way beyond my budget, so I built an Elector terminal kit, which provided all the electronics for a terminal without the screen or keyboard. You connected it to your TV for a display. I also had to build a keypad and a power supply.

It used machine code, so the keypad only needed sixteen keys or so plus a space and an enter key. This was easy to build and I was soon up and running, typing in a whole string of numbers in exactly the right sequence to get the device to display the word ‘HELLO’ on the screen. This after about twenty minutes of solid typing. My family were not impressed, but I was delighted and was jumping for joy. I was ecstatic, I had written my first machine code program and it worked. My enthusiasm did not last for more than a few weeks, because with no tape or disk storage, you always had to spend around twenty minutes or often much longer just to make something happen and what you got was not very spectacular or useful.

 When the Z80 came on the market, I was determined to upgrade. With the Z80, all the keys and display electronics were built in and all I had to do was connect it to a TV to get a display once I had put it together. The Z80 used BASIC and so now I had to learn that computer language. I had made a start at that too, because one of the things I had bought whilst still working in London was a Casio PB-100.

This was a programmable calculator which also ran on BASIC and I had used that to write short programs and so already had some knowledge of how to go about it, but it was still a steep learning curve.

To store programs and load programs on the ZX80, you had to use a cassette recorder, but since most households had one at that time, this was no real issue. A major problem of using a casette to store programs was the time it took to load a program. The accuracy of the reproduction of the cassette player was important. Any wear or dirt on the playback head would prevent a program loading and you would only know it had not loaded after you had waited for the tape to get to the end of the section containing the program you wanted. You could have more than one program on a tape, but had no way of indexing them unless you manually noted down the tape counter, assuming your cassette recorder had one and very few did, so even finding a program was problematical.
Pretty soon a generation of computer users had learned a new word, ’azimuth’. This related to the tape head adjustment, which had to be absolutely vertical or the higher frequencies of the recording were lost. On audio playback this merely muffled the sound a bit, but on a program recording the program would become unreadable. Since cheap cassette recorders were often not too well aligned, some would be a little off vertical. Borrowing a tape from someone else often resulted in failure. Adjusting the head to match the borrowed tape worked but then your old ones would not work, likewise if you had to buy a new cassette recorder your old tapes would not load until you readjusted the azimuth. So computer buffs became very good at adjusting and re-adjusting the playback head of cassette recorders.

The Z80 had some major idiosyncrasies besides this. It only had 1kb of memory, which was a bit limiting, even though it was four times my old PipBug. It could only output the display when the processor was not working on a program. This meant that the results of your program were only displayed at intervals and no animation was possible. The display was black and white and mostly characters with a few crude blocks for simple graphics.

 The following year Sinclair released a much improved computer known as the ZX81. This allowed proper displays that could be animated, but still only in black and white. Both the ZX80 and the ZX81 could be expanded to 16kB of memory if you bought the expansion pack. I eventually bought a ZX81 and an expansion pack and I started to write simple games programs. You could by now buy a lot of software for the ZX81, including a word processor and it is rumoured that Terry Pratchett wrote his first Diskworld novel, The Colour of Magic, on a ZX81.

The year after that, building on the success of the ZX80 and even greater success of the ZX81, Sinclair released the Spectrum. A colour computer that had 16kB of memory built in. This proved to be a real winner for Sinclair and sold millions. Long after its release in 1982, I upgraded from my ZX81 to a spectrum.

Now the boys were old enough to become interested in them and soon I was sitting watching them use my computer, unable to get near until after they had gone to bed.

The Spectrum was much more like a home computer should be. It was able to produce colour animated graphics and could be upgraded eventually to 128kilobytes of memory. You started to be able to buy a lot of additions for your Spectrum that plugged into the rear connector, which allowed printers and even a hard disk to be connected. The keyboard was not special, so you could also buy a kit that allowed a better keyboard to be added to the original works by replacing the top half of the case with a much more useful set of real keys.

A more sophisticated version replaced the spectrum case entirely and you fitted the inner workings inside a 102 key keyboard.

The larger version was almost the same as PC keyboard

Pretty soon I was tinkering with the inner workings of the spectrum and fitting a reset button, a break key and re-writing the ROM to add little touches such as replacing the copyright Sinclair notice with my name. I was able to add more memory without having to buy the Sinclair kit. There was a bug in the original Spectrum ROM which could be exploited if you knew how and many off the shelf programs used this. If you knew how you could, with my added break key, halt a program in the middle and then reverse engineer the code to make your own version. This was not possible on an unadulterated Spectrum and was a little close to infringing someone’s copyright, but we did not think of those things then.

By this time the number one son had his own Spectrum and was writing programs of his own. The number two son never got into computers quite to this level, having written his own program at age eight, he lost interest in that side of it and moved on to war games.

The BBC could have a number of peripherals, such as a floppy disk drive and its own monitor.

Eventually we both upgraded to the BBC computer and tinkered with that instead. The BBC was a lot more sophisticated in many ways, although it used a less powerful processor than the Sinclair computers, it had a neat trick where you could add all sorts of extra functionality using what they called Sideways RAM and Sideways ROM. These were extra panels that you could fit inside the computer where it expanded the capabilities of the system enormously.  It had a built in keyboard and was a lot bigger than the Sinclair computers plus a great deal more expensive but fairly soon you could buy a second hand BBC for a reasonable sum.  The BBC computer was sometimes used in industry and I was amazed once when doing a tour of the local sewage works, as you do, to find they were controlling much of the waste water processing via a bank of BBC computers. The BBC was the last of our pre PC computers and by 1990 we were building our own PCs from off the shelf components and were getting into DOS and Windows. Mind you things were very different then as my first hard disk was 32Mb in size; the maximum DOS could use. It was not until I installed Windows that I could increase the disk to 100Mb and it seemed to me at the time a huge amount of storage space. When you consider that you can now get drives of six Terabytes, which is 60 thousand billion more storage, things have moved on a bit.
One of the interesting side effects of the 80s boom in home computers was that it generated a lot of software savvy computer geeks and many years later when I was teaching computer programming, we started to find a skills gap in our younger candidates. These were people who had not grown up in a house which had an 80s style home computer, but had only ever seen a PC. They had never had to learn programming and so, when they came to us, we had to start teaching them the basics at a much lower level before we could get onto the main syllabus. Something that, thanks to 80s home computers, we had not needed for many years after Sinclair introduced his home computer range. This skills gap is now being covered by the introduction of small hobbyist computers like the Raspberry Pi in schools and so school leavers may soon have caught up with the 80s generation of children.

Summer is long gone but just a reminder…

My post ‘August’ was about some of our days out last summer and this much delayed post is a continuation of that.

For the next day out, we went into London and took The Granddaughter to the Science Museum.

I had not been there since my two boys were children and there have been a number of changes, but it was still mostly as I recall. There are still a lot of interactive displays some of which, as one has come to expect, do not work, but a lot more were a bit more child proof and so did work OK.   One of the newest changes is the Weblab.  Here a number of interactive machines are physically present that you can use, but which can also be accessed through the Internet. 

You need a Weblab tag to get access to the system and it stores your results for future reference.  Once you get home you can show your Weblab tag to a web cam and sign on again, then you can carry on where you left off, or interact with other of the various machines in the Weblab.

You can get machines to draw faces, play music, watch various live sites through 180 degree web cams and so on, or participate in worldwide experiments with this facility.

This machine takes a picture of your face and draws it in sand

A sand picture  from a photo

 I was able to carry out a few of these interactive experiences, but in the end spent most of the time chatting with one of the staff.  This produced a certain kind of conversation that I have often experienced before.

For many people who have a fairly deep understanding in a technical or specialist field, conversations with other specialists starts off with the assumption that the other may not know as much as you.  This is not egotism but common sense.  For instance very few people understand brain surgery, so a brain surgeon talking to someone he does not know, is not going to launch into in depth clinical talk about brain cells unless he is an pretentious idiot, in which case he is unlikely to be a brain surgeon in the first place.

For those of us who have a reasonable depth of knowledge in a particular field, when conversing with someone that you do not know, the conversation starts off with ‘specialist to customer’ level of talk and slowly goes deeper and deeper as each party starts to recognise what the other really knows.  In my conversation as we chatted we each recognised a fellow geek and got deeper and deeper into pure geek until people nearby were seen to scurry away holding their ears.

We were both happy talking about computer systems and the Internet whilst the family were interacting with the Weblab.  During the course of the conversation, I was gratified to find that he had come to the same conclusion that I had come to a few years ago.   Students and computer specialists, even undergraduates, do not understand software as well as people did about twenty years ago.

This may seem at odds to what is happening in our rapidly developing world, because things are becoming smarter and smarter, but we both agreed that as technology improves and becomes easier to use, so ignorance about what is going on under the hood, so to speak, is also growing.

We had both experienced the drop in comprehension of the basics of computer programming in new recruits to the industry over the last few years and we agreed it was almost certainly because no one had home computers any more.  People now have PCs, Macs, or iPads.  You do not learn programming from these because they come ready loaded with easy to use software and so you simply learn which buttons to press.

When people had the old Sinclair Spectrums, Commodores, BBC computers and other brands of home computer available throughout the 1980s and 1990s, they had to learn how to program them before they could do anything with them.  They mostly ran a program called BASIC, a kind of programming language that was actually developed to train programmers.  Very little software was off the shelf and enthusiast magazines printed program listings which you had to type in by hand. Because of this many kids were motivated to write their own programs and many of them, including my own, laboriously taught themselves how to write games software and other programs.  As a result, school kids and young adults had learned the fundamental principles of programming long before they attended college.

Now most kids know how to play Angry Birds, socialise on line and fire off email, but writing any kind of  program, let alone a games program is the preserve of the very few.   We are obviously not alone in thinking this, because recently a new device has been released onto the market, the Raspberry Pi.  A small home computer which is intended to be programmed by the user and does not come with pre-loaded programmes, other than the utilities which allow it to be connected up and run.  It is aimed at schools and is hoped to help instil some of the kind of knowledge the previous generation had gained from their old home computers. 

After the Web lab, the family went into a demonstration and then moved on to more interactive displays.  I was not too interested in them, so I wandered into the flight section and gawped at all the ancient aircraft collected there.  I have always been interested in flying and I spent a lot of my formative years building flying models from balsa wood.  I have taken lessons on occasions so have actually flown myself in a small way, but never got around to acquiring a licence because to keep it up you have to clock up a minimum number of flight hours or it lapses.  In the years we were raising a family, I could barely afford to run a car let alone fly an aircraft, so I never got my licence.  

When I was at the peak of my model building days, I built some scale models of some of the very early designs to see how they flew.  Not all of them did fly I am sad to say, probably my fault, but vintage stuff took my interest for some time.  So anything connected with flight, particularly early flight grabs my interest and there they were, all of the ones I had made, large as life before my very eyes. 

Eventually after a long look at all the exhibits I was able to drag myself away and re-joined the family, who had all been interacting all this time and once back together we returned to the Underground to start our journey home. 

One of the features of the London Underground is that in order to get between stations and other places, you do an awful lot of walking and this tunnel connecting the Underground station and the museum is a fairly good example of this.

A couple of days later we went on a completely different trip, this time to the stately home of Tyntesfield in Somerset, just south of Bristol.

This is not an ancient building but it is quite imposing, with its own chapel standing alongside. Once owned by the Gibbs family, who made their fortune from guano, originally a Regency house stood on the site, but William Gibbs rebuilt it in the 1860s in the rather extravagant Gothic Revival style.  Bought by the National Trust in 2002, it is now open to the public. 

Tyntesfield House

The chapel

The grounds are quite extensive and the Trust provides a bus service to take people around the site.  Since one of our family cannot walk any distance, this service proved very useful. 

One of the busses on its rounds

We had one of the very few nice days of summer and were able to explore the grounds and visit the interior.   It has a lot of flower gardens which were literally buzzing with all kinds of bees busy making sure their hives had enough honey for the coming winter.

 

It was much hotter that day than the weather forecast had predicted and the little ice cream booth ran out of stock around three in the afternoon and we were lucky to get a much needed ice cream, finishing off the entire stock.  The lady selling ices, although apologetic to her disappointed customers, was quite pleased, she told me, because her family had said it would be a waste of time going at all that day and had recommended she took even less stock than she had.

After ices, we wended our way back to the car park and so returned back home.