Patent ID: 8769172

Claim:
An isolated KVM device that permits sharing of peripherals between multiple computers in a multi-network computer system comprising: a USB keyboard input configured to connect to a user keyboard; a USB pointing device input configured to connect to a user pointing device; at least a first USB peripheral interface and a second USB peripheral interface, both configured to connect to at least one first host computer and at least one second host computer, respectively, wherein said at least one first host computer and at least one second host computer are capable of being connected to at least two separate networks, respectively; a host emulator coupled to the user keyboard and user pointing device through said USB keyboard input and said USB pointing device input, respectively, to input keyboard and pointing device data via bidirectional ports and generate single unidirectional serial output signals representing signals input from the user keyboard and the user pointing device; a first USB peripheral emulator and a second USB peripheral emulator, each of the USB peripheral emulators connected to one of said first and second USB peripheral interfaces, respectively, wherein said first and second USB peripheral emulators receives information in said single unidirectional serial output signals and exchanges bidirectional information with said at least one first and said at least one second host computers; a peripheral switch connected to said host emulator to selectively direct said information in said unidirectional serial output signals from said USB keyboard input and said USB pointing device input only to one of said first USB peripheral emulator or said second USB peripheral emulator at a time; at least a first physical unidirectional enforcing circuitry and a second physical unidirectional enforcing circuitry, each connected between said peripheral switch and said first and second USB peripheral emulators, respectively, enforcing unidirectional data flow only from said peripheral switch to the USB peripheral emulators; and wherein said first and second USB peripheral emulators are electrically isolated from one another and all other circuitry in said KVM device other than said first physical unidirectional enforcing circuitry, said second physical unidirectional enforcing circuitry and said host computers.