What is "n-joypad"

The N-Joypad is a Nintendo Entertainment System clone manufactured by the Hong Kong-based company ABL, which is different from other clones because it does not use cartridges, instead relying on " compact discs" (which are actually pieces of plastic) of different size. When the player inserts one of these discs on the system, the disc will trigger a combination of switches on the system which will allow a unique selection of NES games to be selected. The system includes a total of 59 games, which are either original games produced in China, or pirate versions of licensed NES games which with their music and/or graphics hacked to hide their origin.