ESA/390 interpretive-execution architecture, foundation for VM/ESA

	by D. L. Osisek, K. M. Jackson, P. H. Gum
	The interpretive-execution facility of Enterprise Systems Architecture/390 (ESA/390) provides an instruction for the execution of virtual machines. This instruction, called START INTERPRETIVE EXECUTION (SIE), was initially created for virtualizing either System/370 or 370-XA architectures, and was used later for virtualizing ESA/370 and ESA/390 architectures. SIE has evolved to provide capabilities for a number of specialized performance environments. Most recently it provides for the unique requirements of Enterprise Systems Architecture/Extended Configuration (ESA/XC) virtual-machine architecture. This comprehensive set of capabilities in the architecture serves as the platform for the ability of VM/ESA to provide functions in virtual machines for end users and system servers. This paper describes the evolution of SIE and outlines use of the various capabilities in VM/ESA. Related Subjects: Architecture; Operating Systems