Knoop (19xx)(-)(nl) ROM Download can be obtained free for Sinclair ZX81 on EmuGames.net only. Play emulator game in English for the USA region. Knoop is a Sinclair ZX81 ROM that you can download to your computer or play online within your browser. You can also download roms such as Astronaut and Golden Sun 2 L'era Perduta that work on all devices including desktop and mobile. Be sure to rate the game if you enjoyed playing this ROM.