Complex sentence: In 1986, Commodore released the Commodore 64C (C64C) computer, which was functionally identical to the original, but whose exterior design was remodeled in the sleeker style of the Commodore 128 and other contemporary design trends.
Split into simpler sentences: In 1986, Commodore released the Commodore 64C (C64C) computer, which was functionally identical to the original. The exterior design was remodeled in the sleeker style of the Commodore 128 and other contemporary design trends.