T-Mobile MDA Compact IV official Pictures. T-Mobile MDA Compact IV is a Smartphone of t_mobile. The T-Mobile MDA Compact IV Windows Mobile Smartphone. Announced May 2008. Features 2.8″ Display, MSM7201A Chipset, 3.15 MP Primary Camera, 900 MAh Battery, 4 GB Storage, 128 MB RAM. T-Mobile MDA Compact IV price starts.