The Sinclair ZX Spectrum

The Spectrum , released in October 1984, was a stop-gap produced to refresh the Spectrum at a time when the home computer market as a whole was suffering a slowdown.

Sinclair's own surveys showed that the Spectrum's peculiar rubber keyboard was a serious turnoff for prospective users. The Spectrum introduced no changes to the basic Spectrum hardware but provided a "professional keyboard" which had an uncanny resemblance to that of the QL . It was later adapted for the short-lived Spectrum 128 . It was not a proper typewriter-style keyboard as found on PCs, but instead used much the same technology as the old-style Spectrum 48K (and the later Z88 ), with keys - in this case made of injection-moulded plastic - resting on top of a rubber membrane. Many users did not find this wholly satisfactory in practice.

Although the machine sold adequately, the familiar Sinclair quality control gremlins struck again - the keys had an unfortunate tendency to fall off. Retailers reported a failure rate of up to 30%, compared with a more usual 5-6%.