Old and New Mainframe

Old and New Mainframe:-

                    A highly secured computer system designed to continuously run large, mixed workloads at high levels of utilization while meeting user-defined service level objectives.
                    Early mainframe systems were housed in enormous, room-sized metal boxes or frames, which is probably how the term mainframe originated. The early mainframe required large amounts of electrical power and air-conditioning, and the room was filled mainly with I/O devices.
Starting around 1990, mainframe processors and most of their I/O devices became physically smaller, while their functionality and capacity continued to grow. Mainframe systems today are much smaller than earlier systems, and are about the size of a large refrigerator.
                   In some cases, it is now possible to run a mainframe operating system on a PC that emulates a mainframe. Such emulators are useful for developing and testing business applications before moving them to a mainframe production system.

                                    Fig:- Old and New Mainframe        

Physical characteristics of a system:-

• Compatibility with System z operating systems, applications, and data.
• Centralized control of resources.
• Hardware and operating systems that can share access to disk drives with other systems, with automatic locking and protection against destructive simultaneous use of disk data.