Abstract: A desktop computer system is provided with a semi-mobile CPU unit having a portable computer form factor to thereby substantially reduce the desktop area required for the CPU unit. The CPU unit utilizes portable computer internal components, but is constructed without an internal battery pack or power conversion system, and without an integral display, keyboard or pointing device. A recessed support bar is exteriorly carried by an end wall of the CPU unit housing and may be pivoted outwardly therefrom to form a bracing base structure facilitating the repositioning of the CPU unit from a horizontal desktop orientation to a vertical tower orientation.