Amazingly, the Sinclair ZX81 only uses 4 chips (compared to 24 chips used in the ZX80). As well as adding the ability to use floating point numbers for mathematics, the Sinclair ZX81 was also able to output to the Sinclair ZX Printer. Once again, designed by Rick Dickinson the ZX81 is based around a Zilog Z80 chip running at 3.25MHz, and has only 1K of onboard memory, with a 8K ROM chip containing the BASIC and editor. The early ULA in the ZX81 gave a poor TV display on a colour television (hard to see as the background was too dark), although a replacement ULA 2C210E gave a rock steady display. It still had the flat touch-sensitive keyboard which people either loved or hated.

The ZX81 had a similar look to the earlier ZX80, although it adopted the standard Sinclair black colour. ZX80 owners could upgrade their machines to use the ZX81 ROM, with a new keyboard overlay and replacement ROM chip, although the ZX80 lacked some signals on the edge connector. It was manufactured by Timex in Dundee (Scotland) and designed to work on a standard television set and although still available in kit form, could be also purchased ready assembled. We hope this list of software will continue to grow in future updates.The Sinclair ZX81 was released by Sinclair Research Limited) on 5th March 1981 as an upgraded version of the Sinclair ZX80. Special thanks to Nine Tiles for granting permission to include the ROM code, to which they retain the intellectual property rights after all these years.Īdditionally, many thanks to all the developers of the loaded ZX81 software who have all granted permission to include their titles in the app. Meanwhile, another iconic British home computer, the Sinclair ZX Spectrum, was under development and hit the market in April 1982. Timex Corporation and Sinclair Research continued their joint venture and released the Timex Sinclair 1000 (TS1000) and 1500 (TS1500) variants of the ZX81 for the US market in July 1982 and July 1983 respectively. Followed in March 1981 by the even more popular successor, the Sinclair ZX81, both models had a profound impact on home and hobbyist computing in the UK and many other countries.

The computer was developed with another technology company, Nine Tiles, and manufactured in a Timex Corporation factory in Dundee, Scotland. In 1980 the British company Science of Cambridge (later renamed Sinclair Research) released the Sinclair ZX80 home computer. Please note that the system is completely self contained and this means you cannot remotely add code, more games etc. This app focuses on the Sinclair ZX81 experience and is loaded with example software. Welcome to a taste of early 1980s home computing.

Sinclair zx81 emulator