The North and South Koreas have different standards for computer keyboard designs, though both are two sets type keyboards. We expect that the unified design will be three sets type as the third standard. Korean keyboards of three sets type are classified as 3 modes in this paper, such as limited models, medium models, and extended models. Based on design principles of three sets type, 27, 29, 30, 36, and 38 keys models for a unified standard are suggested.