OS/360
OS/360 was a Operating system developed by IBM for their new series of computers System/360, announced in 1964. OS/360 was among the first operating systems to require the use of units of hard drives for its operation.
Origins
OS/360 evolved/moved to become a family of three systems. The first, PCP (Primary Program Control) sequentially treated work one by one; the following, MFT (Multiprogramming with has Fixed number off Task) could treat a fixed number of concurrent tasks, each one occupying a fixed and predetermined part main memory. Finally MVT (Multiprogramming with has Variable number off Task) allowed a variable number of tasks in dynamic partitions of variable size of the main memory.The language of control of work JCL (Job Language Control) was used to structure the batches of perforated cards subjected for treatment with the computer via a card reader. Composed of some kinds, JOB, EXEC, DD, PROC, etc and of many parameters, the JCL made it possible to define the programs, the data and the peripherals for each work subjected to the operating system.
As it was the first time that an operating system of such a great scale was developed, OS/360 was delivered late. Envisaged in an original manner to be delivered in 1965 for the simpler version of PCP and in 1966 for the more complex systems, it was finally delivered with one year of delay is in 1966 for PCP and 1967 for MVT.
A family of alternative systems, bps (BASIC Programming Support) and BOSS (BASIC Operating System) for the smallest computers, TOS (Slap Operating System), for the computers only equipped with uncurlers of magnetic bands, and DOS (Disk Operating System), were produced of speed in order to allow the customers to use their new computers.
Evolution
Although envisaged like temporary system, DOS survived until our days, after its adaptation to the virtual memory under the name DOS/VS (Virtual Storage), became then DOS/VSE (Virtual Storage Extended), then simply VSE, and finally in its current version, VSE/ESA. Following the development of the computers of the series System/370 which allowed virtual addressing, systems OS/360 were updated and famous; MFT became OS/VS1 and MVT OS/VS2 . OS/VS2 was produced under two versions: OS/VS2 Release 1 , also called SVS (Individual Virtual Storage) and OS/VS2 Release 2 , called MVS (Multiple Virtual Storage). SVS was to facilitate the transition from MVT to MVS, and has nothing any more but one historical interest today. MVS is always used on the last models of the series IBM 360 and its successors, the System/370, System/390 and ZSeries, although it changed several times of name during the years, more recently OS/390, now known like Z/OS. Since the new millenium, system OS/360 of origin belongs to the Public domain and can be downloaded free. In addition to turning on System/360 computers, it can be used with the Hercules emulator under GNU/Linux, Windows, and Mac OS X.
References
-
Pugh, Emerson W.; Johnson, Lyle R.; Micrometer caliper, John H. (1991). IBM' S 360 and Early 370 Systems . MIT Near,
Cambridge, MY. (pp. 291-345)
External bonds
- MVS… has long history: OS/360
- Operating System/360 1965-1972