Patent ID: 6141704
Filing Date: 2000-10-31
Classification: G06F

Abstract:
A method of controlling a parallel port for connecting multiple devices to a computer, comprising the steps of:storing a control status and a data status of a first device, which is one of the multiple devices and keeps on-line with said computer, when said computer is to switch on-line state from said first device to a second device (one of the multiple devices);delivering an off-line code from said computer through a data bus to disconnect said first device from said computer and storing control signals of said first device;delivering control signals of said second device through a control bus and an on-line code of said second device through said data bus, from said computer, to connect said second device to said computer and to drive said second device;delivering said off-line code from said computer through said data bus to disconnect said second device from said computer and storing the control signals of said second device, when said computer is to switch the on-line state from said second device to said first device;recovering the control status of said first device stored previously and delivering the on-line code of said first device to connect said first device to said computer; andrecovering the data status of said first device to return to the on-line state of said computer in connecting to said first device.