One Sinclair brochure presented a side-by-side comparison of the ZX81 with the four machines that Sinclair considered its main rivals – the Acorn Atom, Apple II Plus, Commodore PET and TRS-80.
Un folleto da Sinclair presentaba unha comparación do ZX81 coas catro máquinas que consideradas como os seus rivais principais – o Acorn Atom, Apple II Plus, Commodore PET e TRS-80.