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In the 80s school playground, home computers were a bit like football teams. You (or perhaps your parents) picked a team, and that was the side you were on, logic be damned. If you were a Commodore kid, anything from, say, Amstrad or Atari, was just wrong.

We were an Acorn household; specifically, we had an Electron. That, and the closely-related BBC Micros at school, were my introduction to computers, and indelibly shaped how I thought of them. Arguably, we got lucky: out of all of the options, this is perhaps the strongest foundation. However, it’s also a limited one, and as time went on I wondered what might be different if I’d happened to fall into a different bucket.

Fast forward four decades or so, and another visit to the Centre for Computing History. In their line-up of 80s home micros, between an Acorn Atom and an Atari 800, I spotted a Sinclair ZX81. I’d never got anywhere with these machines before due to their weird keyword-entry BASIC (more on this later), but over the course of some Dixons-style light vandalism it clicked for me, and I became intrigued by this odd little machine from the other side of the fence.

10 PRINT "6502 RULES"
20 GOTO 10

There are good emulators easily available, but as the ZX81 was so ubiquitous you can get a real one at a very reasonable price — the going rate on eBay is about £25-30. I picked one up back at the CCH, at their Bring and Byte sale, and after a bit of work on the video output (see Retro Frustrations, Bread and Crocodiles and ZX81 Composite Mod) and adding a modern RAM pack (visible in the photo; see also Mystery RAM) I had a working system to play around with. I’ve also had enough time with it to feel it worth recording my impressions so far.

Firstly, the hardware. Visually, I think it’s a stunner — arguably the best looking micro of the era. Designer Rick Dickinson’s follow-up, the ZX Spectrum is perhaps better known, but for me the ZX81’s wedge shape and black/grey/red graphics has the edge for me (and won Dickinson a British Design Council award).

Thing you notice before even plugging it in is the weight and size. It’s almost square, 16cm across, and little over 3cm deep at its thickest point. This is tiny compared to most other micros at the time, especially if you compare it to (admittedly more capable) behemoths like the BBC Micro and Apple ][. It’s light, too — the first time you pick one up you’d be forgiven for thinking it was just an empty case. In combination, this makes for a device that feels personal and unimposing. It’s not a portable computer, but it’s far more amenable to slinging in a bag to take with you than its peers.

Once you do plug it in and turn it on, you immediately run into one of the things that the ZX81 is most know for: the keyboard. It’s a membrane keyboard, but not in the sense of cheap keyboards today. There are no moving parts at all, and it’s completely flat. It looks gorgeous, and it certainly helped with keeping the cost down, but the typing experience is neither pleasant or quick. You’d think twice about using it to write a shopping list, let alone a novel¹. That said, it isn’t designed for novel writing. It’s designed for one very specific task: programming in BASIC.

Like most almost every home computer of the era, the ZX81 launches directly into BASIC, and its particular flavour is somewhat idiosyncratic. It’s based on a “keyword system”, where BASIC keywords (PRINT, FOR and so on) are entered by a single keypress rather than typing them out in full. The thing that threw me whenever I encountered this in the 80s is that, unlike the superficially similar feature on the Electron, this is not optional. Even though typing the letters individually would produce similar results on the screen, they wouldn’t be recognised as by BASIC. At the time, this seemed very foreign to me, almost gleefully obtuse.

However, once I started to get my head around it, I began to see the benefits. Firstly, it mitigates the awful keyboard, by vastly reducing the number of keypresses you need to achieve an end. It also provides a handy reference, in the form of the intricate key labels. Finally, it reduces the scope for syntax errors, in a similar way to block-based systems such as Scratch.

This last point is an interesting one, as it gets to the heart of my impression of the machine. While other micros were all about doing things (playing games, running spreadsheets, controlling your garden sprinklers), the ZX81 feels like its focus is learning about computers. In the early eighties, computers were still alien to most people, something found in corporations not living rooms. Sinclair’s explicit aim with the ZX81 (and its predecessor the ZX80) was to get computers into the hands of the masses. They did this with a ruthless focus on simplification and cost reduction, and it worked. The ZX81 hit an unheard-of price point (£69.95, going to £49.95 in kit form) and was sold in high street retailers like W.H. Smith, and in only a few years provided well over a million buyers with their first taste of a computer.

This goal was furthered by the manual that came with it, ZX81 BASIC Programming by Steven Vickers (pictured above). All micros of that era came with printed documentation, much of which was of very high quality, but Vickers’ book stands out as a particularly fine example. It takes you through the capabilities of the machine in a logical and patient way, and is an excellent way for a beginner to get up to speed on the key concepts. Coupled with the surprisingly friendly (for the time) interactive environment, it’s easy to see why it gained such traction in the early 80s as an introduction to the brave new world.

This wasn’t to last, however. As the decade progressed, microcomputers became more common, and the focus shifted to more capable devices (not least the ZX81’s successor, the aforementioned Spectrum). Nevertheless, the ZX81 has a special place in many hearts, and having spent a bit of time exploring it I can see why. It does a lot with a little, and has a particular charm of its own. I’m glad I decided to take a look on the other side of the fence.