 The ZX80 's design introduced many key features that were carried over to the ZX81 ; as Sinclair himself later said , " the ZX80 was very much a stepping stone to the ZX81 " . The design was driven entirely by the desired price – the machine had to cost less than £ 100 but still make a healthy profit . Its distinctive wedge @-@ shaped white case concealing the circuitry and the touch @-@ sensitive membrane keyboard were the brainchild of Rick Dickinson , a young British industrial designer who had recently been hired by Sinclair . As he later recalled of Sinclair 's approach , " Everything was cost driven . The design was the face of the machine . " The unconventional keyboard was the outcome of Sinclair 's cost @-@ cutting . It made use of a sheet of plastic , on which the keys were printed , overlaying a metallic circuit that registered when a key was pressed . This avoided the expense of providing a typewriter @-@ style keyboard , though the design had many drawbacks when it came to usability and " feel " . 
