Systems Application Architecture (SAA), introduced in 1987, is a set of standards for

computer software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

developed by IBM. The SAA initiative was started in 1987 under the leadership of Earl Wheeler, the "Father of SAA". The intent was to implement SAA in IBM

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

s including MVS,

OS/400 IBM i (the ''i'' standing for ''integrated'') is an operating system developed by IBM for IBM Power Systems. It was originally released in 1988 as OS/400, as the sole operating system of the IBM AS/400 line of systems. It was renamed to i5/OS in ...

and

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...

. AIX—IBM's version of the

UNIX Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

operating system—was not a target of SAA, but does have interoperability with the SAA family. SAA did not define new standards, but selected from among IBM's existing guidelines and software. IBM also purchased some third party software from developers such as Bachman Information Systems, Index Technology, Inc., and KnowledgeWare, Inc. These were intended to be implemented uniformly across all SAA compliant environments. The standard was "designed to make application programs look and work in the same manner across the entire range of the company's personal computing systems, midrange processors and System/370 processors." SAA was labeled "complex, obscure, and potentially difficult to learn." Under Lou Gerstner IBM later quietly discontinued use of the "SAA"

umbrella An umbrella or parasol is a folding canopy supported by wooden or metal ribs that is usually mounted on a wooden, metal, or plastic pole. It is designed to protect a person against rain or sunlight. The term ''umbrella'' is traditionally u ...

. By 2001, SAA was being spoken of in the past tense. However many of the individual components of SAA are still in use .

Common programming interface (CPI)

The Common Programming Interface attempted to standardize compilers and application programming interfaces among all systems participating in SAA, with the objective of providing "a common programming interface for the entire IBM computer product line - PCs, System/3x, System/370. This implies that under SAA, a program written for any IBM machine will run on any other". CPI included a number of pieces: * Programming languages —

PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language developed and published by IBM. It is designed for scientific, engineering, business and system programming. It ...

COBOL COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural and, since 2002, object-oriented language. COBOL is primarily ...

, Fortran, C,

RPG RPG may refer to: Military * Rocket-propelled grenade, a shoulder-launched anti-tank weapon **''Ruchnoi Protivotankoviy Granatomyot'' (Russian: ''Ручной Противотанковый Гранатомёт''), hand-held anti-tank grenade laun ...

and

REXX Rexx (Restructured Extended Executor) is a programming language that can be interpreted or compiled. It was developed at IBM by Mike Cowlishaw. It is a structured, high-level programming language designed for ease of learning and reading. ...

* Application generator — IBM Cross System Product (CSP) * Communications — Common Programming Interface for Communications (CPI-C) * Database access — SQL * Query interface — QMF * Presentation interface — the OS/2 Presentation Manager was defined to be and when developed was a full implementation of the SAA presentation interface. IBM Graphical Data Display Manager (GDDM) provided compatible SAA graphics support for MVS and VM. * Dialog interface —

ISPF In computing, Interactive System Productivity Facility (ISPF) is a software product for many historic IBM mainframe operating systems and currently the z/OS and z/VM operating systems that run on IBM mainframes. It includes a screen editor, th ...

represented the text mode dialog interface; OS/2 represented the full graphical interface. * Resource Recovery — Common Programming Interface: Resource Recovery (CPI-RR)

Common user access (CUA)

Common User Access aimed at providing "a common user interface for the entire IBM product line. A user who sits down at a PC should see the same menus, keyboards and procedures that he would at a 3270 terminal." Because of hardware differences complete commonality was impossible to attain. IBM created two CUA standards, the ''Basic Interface'' for

IBM 3270 The IBM 3270 is a family of block oriented display and printer computer terminals introduced by IBM in 1971 and normally used to communicate with IBM mainframes. The 3270 was the successor to the IBM 2260 display terminal. Due to the text ...

and

IBM 5250 IBM 5250 is a family of block-oriented terminals originally introduced with the IBM System/34 midrange computer systems in 1977. It also connects to the later System/36, System/38, and IBM AS/400 systems, and to IBM Power Systems systems runn ...

terminals, and the ''Advanced Interface'' for so-called "intelligent workstations", or PCs. The keyboard was standardized to the Model M, 101 key, "AT Enhanced" keyboard layout.

Common communications services (CCS)

Common Communications Services defined the methods by which heterogeneous systems communicated. CCS depended on ''Advanced Program-to-Program Communications'', also known as APPC or

LU6.2 Logical Unit 6.2 is an IBM-originated communications protocol specification dating from 1974, and is part of IBM's Systems Network Architecture (SNA). A device-independent SNA protocol, it is used for peer-to-peer communications between two sys ...

Systems Network Architecture Systems Network Architecture (SNA) is IBM's proprietary networking architecture, created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA describes formats and protocols but, in itself, is not a pi ...

(SNA) PU2.1 or ''Low Entry Networking'' for

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...

networking, and ''SNA Management Services'' for network control. Three types of data links were supported: *

Synchronous Data Link Control Synchronous Data Link Control (SDLC) is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture (SNA). SDLC supports multipoint links as well as error correction. It also runs under the assumption t ...

(SDLC) high speed

wide area network A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits. Businesses, as well as schools and government entities, u ...

s *

X.25 X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts a ...

packet-switched networks *

Token Ring Token Ring network IBM hermaphroditic connector with locking clip. Screen contacts are prominently visible, gold-plated signal contacts less so. Token Ring is a computer networking technology used to build local area networks. It was introduc ...

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...

s (LAN) Application Services were provided by: * CCS supported

data streams, mainly for existing devices *

Document Content Architecture Document Content Architecture, or DCA for short, is a standard developed by IBM for text documents in the early 1980s. DCA was used on mainframe and IBM i systems, and formed the basis of DisplayWrite's file format. DCA was later extended as MO ...

specified a format for documents to be exchanged among different word processors and other software * Intelligent Printer Data Stream (IPDS) was a page description language like Xerox Interpress or Adobe

PostScript PostScript (PS) is a page description language in the electronic publishing and desktop publishing realm. It is a dynamically typed, concatenative programming language. It was created at Adobe Systems by John Warnock, Charles Geschke, ...

* SNA Distribution Services (SNADS) for

store and forward Store and forward is a telecommunications technique in which information is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station. The intermediate station, or node in ...

document transmission * Document Interchange Architecture (DIA) for electronic mail *

Distributed Data Management Architecture Distributed Data Management Architecture (DDM) is IBM's open, published software architecture for creating, managing and accessing data on a remote computer. DDM was initially designed to support record-oriented files; it was extended to support ...

(DDM) for file sharing and as the base architecture of DRDA * Distributed Relational Database Architecture (DRDA) for sharing relational databases

Common applications

OfficeVision was the SAA-compliant successor to PROFS and AS/400 Office for "office automation". The AD/Cycle family of development tools was intended to simplify the development of SAA applications.

References

External links