A data server system and a computer apparatus is provided that can process
external accesses reliably during mobile use. A main PC set in the suspend
or hibernation mode during mobile use is configured so as to read/write
data only from/to an MRAM having no mechanically movable parts and capable
of withstanding higher levels of vibration than a hard disk drive (HDD) in
response to a predetermined operation from a hand-held terminal. A power
supply controller keeps power supplied to the MRAM and stops the supply of
power to the HDD having mechanically movable parts. Whether or not the
main PC is moving is decided automatically by detecting if the main PC is
connected to an AC power source, a LAN cable, and a telephone cable.
