What Happened to the ZX81 Generation?

All you needed to get up and running with the Sinclair ZX81 was a small portable TV. The brief manual told you everything you needed to know and possibly everything there was to know. There was no disc drive but you could save programs and data to a cassette, and also buy programs (mostly games) on cassette. You could also buy a “RAM pack” to boost the memory to 16K, and a strange little printer. Photo: Wikimedia

In 1981 my Dad bought a Sinclair ZX81, to me a legend and one of the most important computers ever made.

Very few people back then would have even seen a computer, and even fewer would have had more than a vague idea of what they did or how they did it. To most people they were just the machines that printed your bank statements and electricity bills.

So the idea of a computer that an ordinary person could go out and buy, connect to their TV and do things with was I believe a major turning point in the history of the human race.

Dad bought it with some vague notion that it would help him run his business. In principle it could: it wouldn't be difficult to write programs to keep track of accounts and invoices, maintain client details, and even store the huge amount of engineering data he needed (specifications of lathes and milling machines, standard thread sizes, coefficients of expansion of various types of metal etc.) but it would have been too cumbersome and time consuming to be practical.

No, what the ZX81 did was to introduce a whole generation to the idea of "A Computer". It was ideal for the task: cheap and simple, but just capable enough to do interesting stuff with.

Of course it wasn't the first home computer and it certainly wasn't the best in purely technical terms but I feel justified in my claim that its ubiquity and influence give it an important place in computer history.

The ZX81 was made in Dundee (irrelevant fact: my maternal grandfather was from Dundee) by watch maker Timex, and was actually sold in the US under the Timex brand rather than as a Sinclair. It sold for just £70 (slightly over £300 in 2020, the price of a low-end laptop) but you could save yourself £20 buy buying it as a kit and building it yourself. I am not aware of anybody doing so…!

It's probably worth spending a bit of time contemplating the machines spec which was very modest even by the standards of the time. It had a Z80 processor which was introduced in 1974 and, amazingly, is still with us today and widely used as a microcontroller. You may own a few without even knowing it.

Now let's look at memory. All 1KB or it. Yes, you got just 1,024 bytes for everything, program and variables. That sounds crippling but you could actually do a lot with it back then, and tweaking code to fit it in to the available memory gave a sense of satisfaction unknown to most programmers these days.

The computer was squeezed into a tiny black plastic case which incorporated a membrane keyboard with just 40 “keys". Many of the keys were used for no less that 5 different things, requiring a high degree of digital dexterity to operate.

A remarkable feature of the keyboard is that it effectively provides a reference manual for the entire computer, complete with all the keywords in the Sinclair Basic programming language and the graphics characters which were indispensable for games.

And of course games were what the ZX81 was mostly used for. A huge industry quickly grew up around this curious little black box, many of the Captains of this Industry being private individuals producing books and cassette tapes at home. Even my boringly ordinary London suburb had an entire shop in the town centre devoted to selling ZX81 stuff.

Frankly most of it wasn't very good. Many of the books were photocopied and bound on one of those office binders that punched holes in a bunch of papers and put a plastic spiral thing along one edge. The books would typically consist mostly of program listings (I don’t think the term “source code" was used then) with free bugs included in the price. Finding and correcting those bugs just seemed normal and was of course a valuable part of the learning experience.

So the life of a ZX81 owner back then consisted of getting home from school, switching the thing on, and pushing the tiny white rectangles on the keypad in a combination which would make something happen on the screen.

The choice of which tiny white rectangles to push, and in what order, might be dictated by a book or magazine but sooner or later you would want to make those choices yourself: to write your own programs.

This was actually way easier than you might think. The machine had the very simple Sinclair Basic language burned into it and as soon as you switched it on you could start typing a program. No text editor, certainly no IDE, no compiler, just code.

Then you would type RUN and the program would do just that.

Actually I lied. Most probably it wouldn't run due to some typo, and even if it did run it would almost certainly have a smattering of bugs. But in a program of 1024 characters at the most they weren’t difficult to find and fix.

And the reward for your hard work? Well, looking back these rewards were quite meagre but I am sure they must have seemed pretty amazing back then. If you were a 15 year old kid then writing a working program would have been by far the most complex thing you had ever done. Maybe it wasn't about the destination but the journey.

But there has always been something that has puzzled me about the ZX81 Generation. What happened to them? I know what happened to me of course: at college I did a lot of coding on Commodore Pets and Apple IIs and then I became . . . an accountant. Fortunately not for long as after a few years I managed to get back on the track the ZX81 set me on in the early 80s.

But what about the rest? A significant proportion of ZX81ers must have gone on to do Great Things in software or hardware or both. Why are they silent, invisible, forgotten? Where is the culture and heritage of that funny little black box? It really is a mystery to me.

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