 Some companies outside the US and UK produced their own " pirate " versions of the ZX81 and Timex Sinclair computers , aided by weak intellectual property laws in their countries of origin . Several Brazilian companies produced ZX81 clones , notably the TK series ( such as the TK85 ) from Microdigital Eletronica of Brazil ) and Prológica 's CP @-@ 200 . Czerweny Eletronica of Argentina produced the CZ1000 and CZ1500 , clones of the ZX81 and TS1500 respectively . Lambda Electronics of Hong Kong produced the Lambda 3000 , based on the ZX81 , which was itself widely copied by other Chinese manufacturers . 
