disk scanner or the like these and other input devices are often connected to the processing unit 121 through a serial port interface 146 that is coupled to the system bus but may be connected by other interfaces such as a parallel port game port or universal serial bus usb a monitor 147 or other type of display device is also connected to the system bus 123 via an interface such as a video adapter 148 in addition to the monitor 147 a personal computer typically includes other peripheral output devices not shown such as speakers and printers the exemplary system of fig1 also includes a host adapter 155 a small computer system interface scsi bus 156 and an external storage device 162 connected to the scsi bus 156 the personal computer 120 may operate in a networked environment using logical connections to one or more remote computers such as a remote computer 149 the remote computer 149 may be another personal computer a server a router a network pc a peer device or other common network node and typically includes many or all of the elements described above relative to the personal computer 120 although only a memory storage device 150 has been illustrated in fig1 the logical connections depicted in fig1 include a local area network lan 151 and a wide area network.