DUCS (software)

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DUCS (Display Unit Control System) was a teleprocessing monitor from CFS Inc. [1] It was one of two early local teleprocessing packages for IBM's DOS/VSE environment. DUCS provided an interface and access method for programmers to 'talk' to monitors. Such access methods later became known as APIs.

Transaction processing is information processing in computer science that is divided into individual, indivisible operations called transactions. Each transaction must succeed or fail as a complete unit; it can never be only partially complete.

IBM American multinational technology and consulting corporation

International Business Machines Corporation (IBM) is an American multinational information technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the Computing-Tabulating-Recording Company (CTR) and was renamed "International Business Machines" in 1924.

User interface means by which a user interacts with and controls a machine

The user interface (UI), in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, whilst the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls, and process controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology.

Contents

Initially written for the IBM 2260 running under DOS on IBM mainframes, the original product was free for IBM users. With the advent of DOS/VS and the IBM 3270 series terminals, the original author commercialized the product, circa 1970. The company added transparent remote access about 1972.

IBM 2260 block-oriented computer terminal released by IBM in 1964

The text-only monochrome IBM 2260 cathode ray tube (CRT) video display terminal plus keyboard was a 1964 predecessor to the more-powerful IBM 3270 terminal line which eventually was extended to support color text and graphics.

Mainframe computer computers used primarily by corporate and governmental organizations

Mainframe computers or mainframes are computers used primarily by large organizations for critical applications; bulk data processing, such as census, industry and consumer statistics, enterprise resource planning; and transaction processing. They are larger and have more processing power than some other classes of computers: minicomputers, servers, workstations, and personal computers.

IBM 3270 family of block-oriented computer terminals introduced by IBM in 1971

The IBM 3270 is a class of block oriented computer terminals introduced by IBM in 1971 normally used to communicate with IBM mainframes. The 3270 was the successor to the IBM 2260 display terminal. Due to the text colour on the original models, these terminals are informally known as green screen terminals. Unlike a character-oriented terminal, the 3270 minimizes the number of I/O interrupts required by transferring large blocks of data known as data streams, and uses a high speed proprietary communications interface, using coaxial cable.

The product is believed to be the first non-IBM publicly available commercial software package to transmit data via satellite. [2]

Application software computer software designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user

Application software is software designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user. Examples of an application include a word processor, a spreadsheet, an accounting application, a web browser, an email client,a media player, a file viewer, an aeronautical flight simulator, a console game or a photo editor. The collective noun application software refers to all applications collectively. This contrasts with system software, which is mainly involved with running the computer.

Satellite Human-made object put into an orbit

In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as Earth's Moon.

Application

DUCS differed from competing products such as Westi and IBM's own CICS in that it was subordinate to the application's mainline program. Westi, for example, was the mainline program and users wrote subroutines to read and write data to and from terminals and discs. This real time paradigm became known as transaction processing.

CICS transaction management system by IBM

Customer Information Control System (CICS) is a family of mixed language application servers that provide online transaction management and connectivity for applications on IBM mainframe systems under z/OS and z/VSE.

In computer programming, a subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed.

DUCS reversed that model in that it was, in fact, a subroutine package that read from and wrote to monitors, both local and remote. While DUCS was considerably easier to program and use, it also placed the onus of task management upon the programmer. Correctly designed, a DUCS program was faster than any competing package or access method.

Development

2260

Dick Goran wrote the original DOS 2260 package. Its popularity made him realize it had potential as a commercial product, and he left IBM about 1970, and incorporated in Brookline, Massachusetts as CFS, Inc.

Brookline, Massachusetts Town in Massachusetts, United States

Brookline is a town in Norfolk County, Massachusetts, in the United States, and is a part of Greater Boston. Brookline borders six of Boston's neighborhoods: Brighton, Allston, Fenway–Kenmore, Mission Hill, Jamaica Plain, and West Roxbury. The city of Newton lies to the west of Brookline.

3270

In 1972, IBM released DOS/VS with the IBM/370 and the first IBM 3270 terminals, and CFS began a rewrite for the new products. Former New York City IBMer, Leigh Lundin, wrote DUCS Remote, a bi-sync module to handle remote teleprocessing. The bi-sync handler was only 4k, in contrast to IBM's BTAM at 28k, QTAM at 36k, and TCAM at 42k, and VTAM which started at 48k.

New York City Largest city in the United States

The City of New York, usually called either New York City (NYC) or simply New York (NY), is the most populous city in the United States and thus also in the state of New York. With an estimated 2017 population of 8,622,698 distributed over a land area of about 302.6 square miles (784 km2), New York is also the most densely populated major city in the United States. Located at the southern tip of the state of New York, the city is the center of the New York metropolitan area, the largest metropolitan area in the world by urban landmass and one of the world's most populous megacities, with an estimated 20,320,876 people in its 2017 Metropolitan Statistical Area and 23,876,155 residents in its Combined Statistical Area. A global power city, New York City has been described as the cultural, financial, and media capital of the world, and exerts a significant impact upon commerce, entertainment, research, technology, education, politics, tourism, art, fashion, and sports. The city's fast pace has inspired the term New York minute. Home to the headquarters of the United Nations, New York is an important center for international diplomacy.

Telecommunications Access Method (TCAM) is an access method, in IBM's OS/360 and successors computer operating systems on IBM System/360 and later, that provides access to terminals units within a teleprocessing network.

Demos

Lundin wrote games in Fortran and Assembler and Goran in COBOL to demonstrate the API for programmers. To model IBM's new light pen, programmers contributed a simple tic-tac-toe (noughts and crosses), possibly the only practical use of the subsequently discontinued light pen.

Marketing

DUCS was sold in North America by CFS, Inc, Brookline, Ma.

For overseas sales, CFS engaged in both mail order and local vendors.

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References

  1. ↑ "Many savings seen with on-line library use", Computerworld, IDG Enterprise, 13 (29), p. 74, 16 July 1979, ISSN   0010-4841, Needing to consolidate four different tape library systems maintaining some 900 programs, Hartman began searching for an on-line librarian compatible with his IBM 370/135, DOS/VS and Power VS configuration. By eliminating all systems that would not support his teleprocessing monitor (the Display Unit Control System [Ducs] from CFS, Inc.), Hartman was left with a choice between Marian, which supports any teleprocessing monitor, and one other system.
  2. ↑ CFS brochure, 1976
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