An operating system consists of a wide collection of programs that manage all the internal workings in a computer system and is aimed at maximizing the computers use which makes the computer faster and the computer can be able to do more work than it used to do. An operating system does not increase the computers speed. Computer architecture is made up of all the functions that is provided by the computer system and is different from its physical design. The system hardware and software found in the mainframe environment, is made up of a highly advanced computer architecture that is so due to the advance in the technological innovation.
The z/OS operating system is the most commonly and widely used of all the other operating systems and it is designed to offer a continuous available computer environment for all that run on the mainframe. The mainframe hardware is made up of processors peripheral devices like the disk drives, user consoles and magnetic tapes.
This operating system consists of programming instructions which control all the operations in the computer system. The z/OS accepts data, converts the data into a form that is easily recognized by the computer, keep track of the work, allocate resources, execute the work, monitor the work and finally, handle the output. The PSW (program status word) which is a 64-bit data area provides crucial details to the hardware and software. By capturing and saving of all the relevant information about a program that was interrupted by this z/OS makes multiprogramming likely.
There are three types of z/OS which are; System-related control blocks, Resource-related control blocks and Task-related control blocks which act as vehicles for the whole of the communication process in the z/OS. They represent so many units of the same type and may be tied together. There are two types of physical storage that are used by the z/OS; the storage located with the mainframe processor itself and the storage that is external to the mainframe like disk drives.
Z/OS paging is usually obvious to the user since during job execution, only the pieces that are necessary and required are paged in. virtual storage is generally an impression that is formed by the architecture. Swapping is a process that involves the transferring the most recently valid pages of an address between the auxiliary storage and the real storage which makes it one of the methods used by the z/OS to balance the system workload and to ensure that an adequate supply of available real storage frames is managed.
Peripheral storage devices management in an operating system involves backup, file allocation, migration, recovery, placement and deletion. These processes can either be automated, or done manually depending on the z/OS where a user can easily control any aspect of storage and is suited for processing complex workloads, access huge data amounts and even comprehensive security.
The mainframe operating systems rarely give complete operational environments since they also depend on other products and functions for middleware. All the programs running the z/OS can run with 24-64 bit addressing and can also switch. The systems use of multiprocessing and multiprogramming and the ability it has to manage and control large amounts I/O operations and storage, makes it suitable for running the mainframe workloads.
Over the many years, operating systems were developed to meet the needs of computers in the market this led to the development of applications which can run on z/OS like UNIX where the z/OS contains a full UNIX set of operating systems besides its traditional z/OS interfaces.