TK 85

The TK85 was a ZX81 clone made by Microdigital Eletrônica, a computer company located in Brazil. It came with 16 or 48 KB RAM, and had a ZX Spectrum–style case, similar to a Timex Sinclair 1500.

Unlike the ZX81, the TK85 used standard logic components rather than a gate array ("ULA"), and during manufacture several of them were scraped so that competitors couldn't easily copy the circuit. The circuit board had space for a AY-3-8912 sound generator chip (compatible with the ZonX-81 sound board), and although none came factory installed, it is possible to add the necessary circuits.