Tape Loading Error 1 - Do It Yourself

Computers have come a long, long way in the last 70 years. If you asked people to name the first examples of computers, they would probably come up with  things like Charles Babbage's Difference Engine from the early 19th century, or the 'Bombe' machine developed by Alan Turing to decrypt the German Enigma code in World War II. Others might remember devices called 'Colossus' or 'ENIAC' - number crunching behemoths the size of a house and weighing tons, powered by thousands of vacuum tubes, resistors, capacitors and inductors. These were creations of unique teams or individuals and primarily used by the military. It was the development of the transistor and then integrated circuits in the 1950s  - which in turn led to the development of the microprocessor -  which has transformed modern society.

Today there is more processing power in an iPhone that there was in the machines on board the Apollo mission rockets that took men to the moon. Computers (and the internet) are so inextricably woven into out lives and our homes that we interact with them hundreds of times a day, sometimes without even noticing. It wasn't always like this though and nowhere is this more obvious that in the world of home computers and video games. It's hard to believe in these days of market domination by Microsoft Windows and X-Box's and Sony PlayStation's and Apple Apps that there was a time over 30 years ago when the UK led the way with the development of home computers. When the most popular games 'console' in the UK was a rubber keyboarded thing the size of a hardback book with a massive 48k of memory. When game developers worked out of their bedrooms, and innovation was more important than realism. But I'm getting ahead of myself. Let's first go back in time to the birth of the devices that really founded the British home computer market...

By the late 1970s, thanks to the aforementioned  microprocessor, everyone in the UK was familiar with pocket calculators and digital watches. I remember getting my first ones of each with their distinctive red LED display around 1978 / 1979. We had also been exposed to some of the first rudimentary electronic games  - initially versions of the basic "pong" or tennis, with classics such as Electronic Mastermind, Merlin and Simon appearing later on toy shop shelves. But these were expensive gadgets that not everyone could afford and if you knew someone who had one, they were the most popular kid in school (I might do a whole separate post about the evolution of these games at some point).

However the initial attempts at producing an actual computer for the home market were aimed at the electronics hobbyist - mere kits requiring copious amounts of electronic components, wire and solder (and skill) to put together with the printed circuit boards and primitive silicon chips. Devices such as the Altair 8800, which appeared in 1975, could only be "programmed" by tedious toggling of multiple switches to set the instruction, loading that into the tiny memory and then repeating over and over and over again. The only output you got from all that hard work was the specific blinking of lights on the front panel.

By 1978, circuit boards and processors had developed sufficiently that a more sophisticated machine could be produced, leading to the appearance of the NASCOM-1. Still firmly directed at the niche enthusiast (as it required home assembly and the soldering of over 3000 joints) and costing a then eye-watering £200.00, it was based on the then new Z80 processor and boasted a real keyboard and suitable interfaces for connecting the machine to a TV display and a cassette player (tapes being a cheap alternative to floppy disks). Both the Z80 chip and the tape recorder would form an integral part of the success of the home machines to come.

With hard work and more than a little patience, users could even create rudimentary games on the NASCOM machines:

Of course games created by bored mainframe programmers had been around for decades. "Spacewar!", designed by some of the first "hackers" on  the PDP-1 at the Massachusetts Institute of Technology (MIT) in 1961, is credited as the first widely available computer game - but there are many others such as "Hunt The Wumpus (1973) and of course Colossal Cave Adventure (1976) that are equally well known. I can remember that even when I first started work in the mid-1980s, the company mainframe still had a copy of "Adventure" on it (if you know who to ask)..

It's also at this point in 1978 that inventor, entrepreneur and all round genius Clive Sinclair comes into the picture. His company 'Science Of Cambridge' produced the MK14 - the first really cheap mail order computer kit in the UK, retailing at £39.95 plus tax. It was not as powerful as things such as the NASCOM-1, being more a machine designed for learning about programming. With a then reasonable 256 bytes of RAM (expandable up to 512), a *very* basic keyboard,  plus interfaces to allow it to connect to a cassette player for storage and a standard TV set for display (at additional costs of £7.99 and £33.75 respectively), it was originally expected to only sell in small numbers. Demand was vastly underestimated and from an initial production run of 2,000 units, it went on to sell ten times that (accurate totals vary) - significantly expanding the user base of hobbyist computers. The MK14 was so successful in fact that it gave 'Science of Cambridge' the capital to embark on their next venture - a computer with wider mass market appeal.

Having dabbled in building simple electronic projects like Crystal radio sets, sound effect generators, door buzzers,etc  I was aware of the MK14 from trips to stores like "Maplins" to pick up supplies of components. But for whatever reason, building something like that didn't really appeal to me. Having visited science and computer fairs as part of school trips, I was really interested in something that was a bit more "complete".

Following the success of the MK14, Clive Sinclair looked to the US, where there were three big machines dominating the computing market - the Apple II, the TRS-80 and the Commodore PET. These were proper desktop computers used in offices but were hugely expensive and Sinclair knew that to target a wide enough market he would have to come up with something innovative. Two years later in February 1980, "Science of Cambridge" released their next project - the ZX80. As with the MK14, the idea was to provide a cheap entry point to personal computing. Available in kit form for £79.95 or ready assembled for under the magic, consumer-pleasing, £100, this indicated a real shift towards a more general audience. It even came with a fully functioning keyboard- albeit a membrane one - and was completely enclosed within a stylish case. It had only 1K of RAM out of the box, but crucially could be expanded up to 16k via an external expansion pack, which simply plugged into the back of the machine, requiring no soldering or electronics experience. As was now becoming standard, connections to a cassette player for storage and a TV for viewing were provided.

One of the limiting factors of the ZX80 however was that there was no sound and the display was still black and white and flickered constantly. The hardware was unable to hold the screen image and process other tasks at the same time - if you wanted it to do a calculation, the screen went blank until it was completed (oh and it could only deal in whole numbers). A counter to this was that the machine came with "Sinclair BASIC" - it's own programming language based on the ANSI standards co-developed by Microsoft founder Bill Gates. For the first time the general user (with the support of the included user manual) could write their own programs!  Books started to be published with listings of all the BASIC commands necessary to create your own software. 

Even though the machine was inferior to its rivals, sales were impressive: over 50,000 units. The ZX80 really turned the market on its head. The sub-£100 price point and the fact that one could simply walk into a shop, buy one, plug it in and use it was unheard of at the time. It's success demonstrated that there was a massive potential market out there for a cheap consumer-friendly home computer. I desperately wanted a ZX80, but had to satisfy myself with visiting my friend David after school, because his parents had splashed out and bought him one. We used to sit their in awe as he proudly showed off his hours of programming skills by making a minimalist text game or Breakout, or something that was meant to be a flight simulator. It was the dawn of a new age. A black and white one with no sound maybe, but still a new world of possibilities.

In the next episode - we reach 1981 and I take my first steps into the world of home computing...