DUCS (software)
Encyclopedia
DUCS was one of two early local teleprocessing
packages for IBM
's DOS/VSE environment. DUCS was an acronym for Display Unit Control System.
and access method
for programmers to 'talk' to monitors. Such access methods later became known as API
s.
Initially written for the IBM 2260
running under DOS on IBM mainframe
s, 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.
The product is believed to be the first non-IBM publicly available commercial to transmit data via satellite
.
and IBM's own CICS
in that it was subordinate to the application
's program. Westi, for example, was the mainline program and users wrote subroutine
s to read and write data to and from terminals and discs. This real time paradigm became known as transaction processing
.
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.
as CFS, Inc.
terminals, and CFS began a rewrite for the new products. Former New York
IBMer, Leigh Lundin, wrote DUCS Remote, a bi-sync module to handle 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.
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.
For overseas sales, CFS engaged in both mail order and local vendors.
Telecommunications Access Method
Telecommunications Access Method 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....
packages for IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
's DOS/VSE environment. DUCS was an acronym for Display Unit Control System.
The product
DUCS provided an interfaceUser interface
The user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the...
and access method
Access method
An access method is a function of a mainframe operating system that enables access to data on disk, tape or other external devices. They were introduced in 1963 in IBM OS/360 operating system...
for programmers to 'talk' to monitors. Such access methods later became known as API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
s.
Initially written for the IBM 2260
IBM 2260
The text-only 960-character monochrome IBM 2260 cathode ray tube video display terminal plus computer keyboard was a 1964 predecessor to the more-powerful color text-and-graphics IBM 3270. The 2260 screen image was normally configured with 12 lines of 80 characters each, which corresponded to IBM...
running under DOS on IBM mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s, the original product was free for IBM users. With the advent of DOS/VS and the IBM 3270
IBM 3270
The IBM 3270 is a class of block oriented terminals made by IBM since 1972 normally used to communicate with IBM mainframes. As such, it 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...
series terminals, the original author commercialized the product, circa 1970. The company added transparent remote access about 1972.
The product is believed to be the first non-IBM publicly available commercial to transmit data via satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
.
Application
DUCS differed from competing products such as WestiWesti (software)
Westi was one of two early local teleprocessing packages for IBM's DOS/VSE environment. Westi stood for Westinghouse Terminal Interactive.- The product :...
and IBM's own CICS
CICS
Customer Information Control System is a transaction server that runs primarily on IBM mainframe systems under z/OS and z/VSE.CICS is a transaction manager designed for rapid, high-volume online processing. This processing is mostly interactive , but background transactions are possible...
in that it was subordinate to the application
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
's program. Westi, for example, was the mainline program and users wrote subroutine
Subroutine
In computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....
s to read and write data to and from terminals and discs. This real time paradigm became known as transaction processing
Transaction processing
In computer science, transaction processing is information processing that is divided into individual, indivisible operations, called transactions. Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state...
.
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.
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, MassachusettsBrookline, Massachusetts
Brookline is a town in Norfolk County, Massachusetts, United States, which borders on the cities of Boston and Newton. As of the 2010 census, the population of the town was 58,732.-Etymology:...
as CFS, Inc.
3270
In 1972, IBM released DOS/VS with the IBM/370 and the first IBM 3270IBM 3270
The IBM 3270 is a class of block oriented terminals made by IBM since 1972 normally used to communicate with IBM mainframes. As such, it 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...
terminals, and CFS began a rewrite for the new products. Former New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
IBMer, Leigh Lundin, wrote DUCS Remote, a bi-sync module to handle teleprocessing. The bi-sync handler was only 4k, in contrast to IBM's BTAM at 28k, QTAM
QTAM
Queued Telecommunications Access Method is an alternative to the simpler Basic Telecommunications Access Method communications access method, introducing built-in queuing. It was developed by IBM as part of DOS/360 and OS/360 and used mainly to transmit batches of data...
at 36k, and TCAM
Telecommunications Access Method
Telecommunications Access Method 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....
at 42k, and VTAM
VTAM
Virtual Telecommunications Access Method is IBM's software package that provides communications via telecommunication devices for mainframe environments. It is the implementation of Systems Network Architecture for mainframes...
which started at 48k.
Demos
Lundin wrote games in FortranFortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
and Assembler
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
and Goran in COBOL
COBOL
COBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
to demonstrate the API for programmers. To model IBM's new light pen
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
, programmers contributed a simple tic-tac-toe
Tic-tac-toe
Tic-tac-toe, also called wick wack woe and noughts and crosses , is a pencil-and-paper game for two players, X and O, who take turns marking the spaces in a 3×3 grid. The X player usually goes first...
(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.