An imaging modality includes a first computer, a second computer, a computer select circuit connected to a manually operable switch and configured to allow an operator to select whether to operate the first computer or the second computer by manually operating the manually operable switch, a single power supply unit configured to supply operating power to the first computer and the second computer; and a power control circuit connected to a power input of the first computer and connected to a power input of the second computer. The power control circuit outputs a trigger signal to activate or deactivate flow of power supply to the second computer in response to first computer receiving a turn ON or turn OFF input.