The ZX Spectrum (and its unique “gummy” keyboard) was for many young Britons the first introduction to the computer world and the biggest commercial success of the company founded by Sir Clive Sinclair. Originally released to the public in April 1982, it was designed with the same philosophy as its predecessor ZX81: being the cheapest home color computer on the market. The hardware part was designed by Richard Altwasser of Sinclair Research, while the software by Steve Vickers. The infamous keyboard is instead the brainchild of the industrial designer Rick Dickinson, who had also taken care of the (not very aesthetically happy) cases of the ZX80 and ZX81.
The Spectrum was a remarkable step forward compared to the ZX81: It had more memory, the colors (hence the name Spectrum) and the audio. As for the sound part, the Spectrum was not very well equipped, and the small loudspeaker supplied, despite the great effort, could not emit nothing but than shrill beep. It seems that this “lack” can be attributed to a forced choice to reduce production costs. In fact, in the original project, the Spectrum had to be developed with a more performing sound system.
On paper, the Spectrum was a graphically well-equipped computer. The resolution of 256×192 pixels in fact was higher than that of the competing computers and could display 8 colors on the screen, which could increase in number with particular functions. The problem was that only two colors could be used for each square of 8×8 pixels. This led to the terrible “color clash” phenomenon of the Spectrum: When graphic elements with different colors overlapped on the screen they “kneaded” creating annoying visual effects. Many programmers were able to solve this problem by using few colors or trying to limit them only to certain areas of the screen.
The graphic part of the Spectrum was also affected by other small hardware design flaws that were solved only with the release, in 1984, of the Spectrum +.
These hardware “defects” were the natural and inevitable result of product planning, which had as its objectives reduced costs and design simplicity. But this combination of economy and simplicity was the key to the success of the Spectrum, which was accepted with great enthusiasm by the newly born market of home users.
The Spectrum was initially produced in two versions, basically identical: the 16k version and the 48k version. It was possible to “upgrade” the one with lower memory through an expansion kit. Given that the price difference between the two versions was relatively low, buyers quickly turned to the 48k one, decreeing the slow disappearance of the 16k one.
Sinclair also produced a series of accessories for the Spectrum which, however, found a very cold response from the market. This is the ZX INTERFACE 2 and allowed the Spectrum to use particular cartridges and to connect up to two joysticks with universal connection to the computer.
Production of the Spectrum started with 20,000 units a month, with a sales perspective of 300,000 units per year. The demand, however, was enormous, far exceeding the quantities available, and Sinclair took a long time to distribute the units booked. Over the months, Sinclair found itself with tens of thousands of units ordered but not yet produced and was severely fined even by the Authorities for misleading advertising. In fact, Sinclair in its advertisements promised a delivery in 28 days from the order. Sinclair’s delays and problems also fueled the market for illegal “clones” that were sold around the world. Ironically it was these “clones” that allowed the Spectrum phenomenon to last long, lasting many years longer than the original.
In the end, the slow increase in production by Sinclair allowed the company to be recovered and the backlog to be canceled. This, combined with an expansion of the stores and the lowering of the cost of the units, allowed Sinclair to greatly increase its profits and to transform the Spectrum into the most sold computer in England.
One of the trump cards that contributed to the spread of the ZX Spectrum was the immense amount of software available. This is thanks to all the experienced programmers that the ZX 81 had formed around the world. In their garages or in their home studios, young students began to write their programs, often selling them to software houses or setting up their own. In a short time, hundreds of magazines were born around Europe which, by publishing first lists and then, later, cassettes with programs, allowed the spreading of the Sinclair phenomenon.