Pink Floyd, the BBC (Hitchhikers’ Guide and Doctor Who), and Tangerine Dream all used the original. Now the Synthi A gets a free homage in your Web browser.
There’s an interactive scope for seeing what you’re doing, and loads of onscreen controls. You can even load audio files. The developer put in some nice extras, too, like letting you choose which kind of interaction you want when you mouse over knobs (“turning” them radially or sliding vertically). You can store presets, since this is a computer and not vintage hardware. And you can generally play around.