Patent ID: 6070224
Filing Date: 2000-05-30
Classification: G06F

Abstract:
A method for operating a magnetic disk storage device as a virtual tape device available responsive to tape requests for input-output operations from a user program in user address space of a main memory of virtual operating system, the main memory including a pointer to a standard input-output module that effects input-output operations with other input-output devices, said method comprising the steps of:A) establishing a virtual tape program address space in the main memory including a server program with a command converter, an index and a second input-output module,B) altering the contents of the pointer whereby all input-output requests are handled initially by the second input-output module,C) selecting in the input-output module those tape requests for the virtual tape device and, in response thereto:i) converting in the command converter a tape request to a disk request for the magnetic disk storage device,ii) effecting an operation defined by the disk request with the magnetic disk storage device,iii) generating a return code based upon the operation of the magnetic disk storage device for the user program, andiv) updating the index thereby to maintain current correspondences between tape locations and magnetic disk storage locations,D) enabling the standard input-output module to process commands for other input-output resources.