Ringo R470 was a Brazilian clone of the

Sinclair ZX81 The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-cost ...

by Ritas do Brasil. It has a Z80A at 3.25 MHz, 8K ROM and 16 KB RAM. It wasn't 100% compatible with the ZX81.

References

Computers designed in Brazil Goods manufactured in Brazil Sinclair computers and derivatives Z80-based home computers {{comp-hardware-stub