Soul of an old machine

The joy of 16k RAM

When tech gets retro

It was the size of a small book and had a mere 1k in memory and cost €320 at today’s prices, but the Sinclair ZX81 brought computing into the home.

The display was monochrome, plugged into a TV rather than a monitor, with a graphics mode pixel density of 64 by 48 and used an ordinary cassette tape to load and save data.

It wasn’t much, but we shouldn’t sneer, but be very grateful to its inventor, Sir Clive Sinclair, who was already a leading innovator a decade previously, when he brought out the first real pocket calculator in 1972, the Sinclair Executive and a year later, the Sinclair Cambridge. The designs were clean and clear, if a little ‘boxy’ looking, but what they to appear to have predicted what smartphones would look and feel like.

On that comparison, in 1977, Sinclair brought out a calculator that was worn like a watch.

Like everything else, Sinclair was interested in basic products that had few components and could be sold at a price far below any competitors. But in computing, he was both right and wrong. He rightly thought that people would want a computer in every home, which went against the prevailing wisdom, even inside the industry, puzzled over what non-commercial uses there would be. Typical thinking was that maybe some household accounting, beyond that even experts were stumped.

But he was wrong when he thought people would learn to program. He wasn’t entirely wrong. His machines were taken up by teenagers who became the generation that built so much of today’s digital architecture.

There were schoolboys returning to the bedrooms to code the first primitive but still enjoyable games and this led to the independent software market and to what we now call the ‘App Economy.’

Programs became available through interesting ways, some BBC programmes about computers often had downloads available, either by playing a bar code in the corner of the screen or the electronic screech during the end credits that could be recorded on a cassette player and then loaded onto the ZX.

The memory limitations also encouraged good practice. Programs had to be very well written to run on 1k of memory and perhaps one of the highest achievements in computing was 1k Chess. Sure it was a bit limited, but can you imagine playing chess with so few bits spare?

By March 1982, a quarter of a million had been sold, either as build it yourself kits or pre-assembled. By July 1983 1.5 million had been bought.

Part of the success was the strategy, being sold in high street shops, rather than specialist retailers. They were even on sale in airport duty free shops, until that was halted by the government, worried that Russians would pick one up and use it for nefarious plots and plans.

This didn’t stop Sinclair signing a contract to have the machines built in Guangzhou, China in November 1983.

Many old users of the ZX would smile at the nes that Britain’s best selling computer today is the Raspberry Pi, the ultra stripped down computer that was conceived after computer scientists noticed applicants to their courses were becoming less skilled each year.

Previously, those wishing to study computer science had been hobbyists on machines like the ZX81, now they have done some minor web design at most.

The boffins thought this was because home computing had moved on from programmable computers to the ‘sealed box’ of modern PCs and Macs.

They produced the Raspberry Pi, a cheap, programmable home computer.

Over five million have been sold.