Emulating the Sinclair ZX81 in JavaScript

This site demonstrates (a minor fork of) Simon Holdsworth's JtyOne JavaScript Emulator. JtyOne was based on Mike Wynne's EightyOne Sinclair Emulator (written in C#) that was notable for being able to accurately emulate ZX81 games that offered pseudo high-res graphics like Forty Niner and Rocket Man from Software Farm.

You can learn about the emulators at zx81-javascript-emulator.