How do automatic mahjong machines put two pairs of mahjong in the mahjong machine?

Expanded data: The automatic mahjong table was first invented and produced by Japan. The fully automatic mahjong table was originally imported from Japan into China by a small amount. Since then, because of the huge market in China, the Japanese opened factories in China in the early 1990s. The mass production of the fully automatic mahjong machine has brought the mahjong machine to China.

The general mahjong machine is a four-port machine, that is, when you put a deck of cards to wash, when you wash it, put the second pair down, then you press two dice buttons at the same time (note. Press can only be something, or North and South,), at the same time in the middle of about 10 seconds can go down.