PL/S, short for Programming Language/Systems, is a "machine-oriented" programming language based on PL/I. A programming language is an Artificial language that can be used to write programs which control the behavior of a machine particularly a Computer. PL/I ("Programming Language One" ˌpiːˌɛlˈwʌn is an imperative computer Programming language designed for scientific engineering It was developed by IBM in the late 1960s as a replacement for assembly language on internal software projects; it included support for inline assembly and explicit control over register usage. International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology The 1960s decade refers to the years from the beginning of 1960 to the end of 1969 See the terminology section below for information regarding inconsistent use of the terms assembly and assembler In Computer programming, the inline assembler is a feature of some Compilers that allows very low level code written in assembly to be embedded in a In Computer architecture, a processor register is a small amount of storage available on the CPU whose contents can be accessed more quickly than storage
Early projects using PL/S were the batch utility, IEHMOVE, and the Time Sharing Option of MVT, TSO. IBM mainframe utility programs are supplied with IBM mainframe Operating systems such as MVS to carry out various tasks associated with datasets In Computing, the Time Sharing Option ( TSO) is an interactive Time-sharing environment for the lineage of IBM mainframe operating systems running
By the 1970s, IBM was rewriting its flagship operating system in PL/S. This article is about the Decade 1970-1979 For the Year 1970 see 1970. Although users frequently asked IBM to release PL/S for their use, IBM refused saying that the product was proprietary. Their concern was that open PL/S would give competitors, Amdahl, Itel (National Advanced Systems), Storage Technology Corporation, Trilogy Systems, Magnuson Computer Systems, Fujitsu, Hitachi, and other PCM vendors a marketing advantage. Amdahl Corporation was founded by Dr Gene Amdahl, a former IBM employee in 1970 and specializes in IBM mainframe -compatible computer products Storage Technology Corporation ( StorageTek or STK) is a worldwide technology Company that delivers a broad range of data storage offerings Trilogy Systems Corporation was a computer systems company started in 1980 Magnuson Computer Systems was a manufacturer of IBM-compatible mainframes. is a Japanese company specializing in Semiconductors Computers ( Supercomputers Personal computers, servers, Telecommunications () is a Multinational corporation specializing in high-technology and services headquartered in Marunouchi Itchome Chiyoda, Tokyo, Japan. A plug-compatible machine is one that has been designed to be Backwards compatible with a prior machine However, even though they refused to make available a compiler, they shipped the PL/S source code to large parts of the OS on microfiche to customers, many of whom thus became familiar with reading it.
Closed PL/S meant that only IBM could modify and enhance the operating system.
In the mid-1970s, a single programmer, working from publicly available documentation, wrote a fully functional PL/S compiler. IBM legally suppressed this software.
This was RAND corporation. They made the mistake of using internal IBM documentation for their development, which they did not have permission to use for this purpose, and IBM threatened to sue them, so they never offered the product for sale. They did however advertise its imminent release through SHARE meetings. SHARE Inc is a volunteer-run user group for IBM Mainframe computers that was founded in 1955 by Los Angeles-area IBM 701 users
PL/S was succeeded by PL/AS (Programming Language/Advanced Systems), and then PL/X (Programming Language/Cross Systems). PL/DS was a closely related language used to develop the DPPX operating system, and PL/DS II was a port of the S/370 architecture for the DPPX/370 port. Distributed Processing Programming Executive was an Operating system introduced by IBM pre-installed on selected computer
As the market for computers and software shifted away from IBM mainframes and MVS, IBM recanted and has offered the current versions of PL/S to selected customers (ISVs through the Developer Partner program. )
References
- W. R. Brittenham, "PL/S, Programming Language/Systems", Proc GUIDE Intl, GUIDE 34, May 14, 1972, pp. 540-556
- W. R. Brittenham and B. F. Melkun, "The Systems Programming Language Problem", Proceedings of the IFIP Working Conference on Machine Oriented Higher Level Languages, Trondheim, Norway, August 29-31, 1973, pp. 29-47. Amsterdam: North-Holland Publishing Co. ; New York: American Elsevier, 1974. This paper explores the technical and psychological problems encountered in implementing PL/S. The language and compiler are described. The discussion that followed presentation of the paper is included.
- Gio Wiederhold and John Ehrman, "Inferred SYNTAX and SEMANTICS of PL/S", Proceedings of the SIGPLAN symposium on Languages for system implementation 1971, in SIGPLAN Notices 6(10) October 1971
- Guide to PL/S II, International Business Machines Corp. Gio Wiederhold is Emeritus Professor of Computer Science at Stanford University, with courtesy appointments in Medicine and Electrical Engineering , 1974. GC28-6794-0 Note that this manual is very out of date with respect to the PL/X language in use today.
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic