The present invention provides a common interface among device drivers 5 operating in the kernel 8, for increasing data transfer speeds and improving data integrity. A common interface driver 7 is provided among device drivers 5, which control devices 6 connected to a computer. The common interface driver 7 operates in the kernel mode 8 and provides an interface with the application program 4. The common device driver 7 receives and analyzes commands from the application program 4 and outputs instructions to each of the device drivers 5.