METHOD AND APPARATUS FOR EXECUTING INPUT/OUTPUT OF VIRTUAL COMPUTER SYSTEM

摘要

PURPOSE:To reduce an I/O simulation overhead and to make a VMS highly efficient by constituting an I/O instruction executing circuit and an I/O interruption executing circuit by hardware and executing I/O under control by the hardware. CONSTITUTION:If an I/O channel of a virtual computer in running is occuplied and an I/O instruction is generated from the running virtual computer to the I/O channel in the virtual computer system for running one or plural operating systems by one computer, an AND circuit 2600 outputs ''1'' to a line 4200 to allow a selecting circuit 1900 to select a real channel number. In a high-speed VM mode, the channel number of the occupied I/O channel is converted from the virtual number to a real number by the hardware.