Fuse is an emulator of the popular 80's home computer, the Sinclair ZX Spectrum, and its many variants. As we write, these include: "16K, 48K (including the NTSC variant), 128K, +2, +2A and +3; +3e, SE, TC2048, TC2068, TS2068, Pentagon 128, Pentagon "512" (Pentagon 128 modified for extra memory), Pentagon 1024 and Scorpion ZS 256".
The program emulates every aspect of the ancient computer: sound, joystick, Kempston mouse, printers, the Spectranet and SpeccyBoot interfaces, and more. The end result will still be horribly low-res graphics with very annoying sound, but it will at least be just like the original.
You don't have to get involved with the technicalities, of course. If you find a game you remember (the World of Spectrum is a great place to start looking), just download and double-click it. Fuse will generally open and launch the game immediately, and all you have to do is play.
If you do want to go further, though, there's plenty to explore. Just about every aspect of the emulator can be tweaked and reconfigured. And if you'd like to share your experiences with others, there are options to take screen grabs, or even save your gameplay as a video file.
Great fun for anyone with fond memories of the Spectrum.