1. A method of enabling an application program executing on a virtualized legacy computer system to access physical hardware of a host computer system, comprising: when an attempt is made by said application program to access hardware of said virtualized legacy computer system, generating a memory access violation; providing to an emulation device of said host computer system information identifying at least the hardware of said virtualized legacy computer system that said application program attempted to access; and said emulation device of said host computer system emulating the hardware of the virtualized legacy computer system to effect the activity expected by said application program in response to the requested hardware access of said virtualized legacy computer system.