Conversational Programming System
Encyclopedia
Conversational Programming System or CPS was an early Time-sharing
system offered by IBM
which ran on System/360
mainframes
circa 1967 through 1972. CPS was implemented as an interpreter
, and users could select either a rudimentary form of BASIC
or a reasonably complete version of PL/I
. A third option provided remote job entry
(RJE) features allowing users to submit JCL
JOB Stream
s for batch processing. A fourth option was called control mode. Normally, only the system operator would be permitted to use control mode. The available features in control mode included:
CPS provided a highly interactive user experience. It accomplished this by giving an immediate syntax error
(when necessary) as soon as each line of a program was entered.
CPS was also offered with a firmware-assisted interpreter, on the System/360
Model 50, only, but few Model 50 installations elected to install this RPQ. This RPQ executed the EVAL function of CPS's programming stack using a firmware assist.
The IBM-released version of CPS was designed to run on the IBM 1050
terminal and the IBM 2741
terminal with the "break feature". User groups later added support for the IBM 2260
terminal.
CPS support for the IBM 2741
"break feature" most likely influenced the eventual user group support for the "break feature" and the IBM 1050 terminal on ATS/360
, as many IBM customers which operated CPS also operated ATS/360.
CPS was ultimately superseded by TSO
. An IBM program product was offered which provided limited CPS functionality under TSO
, intended mainly as a "bridge" between CPS and TSO
.
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
system offered by 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...
which ran on System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
mainframes
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...
circa 1967 through 1972. CPS was implemented as an interpreter
Interpreter (computing)
In computer science, an interpreter normally means a computer program that executes, i.e. performs, instructions written in a programming language...
, and users could select either a rudimentary form of BASIC
BASIC
BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
or a reasonably complete version of PL/I
PL/I
PL/I is a procedural, imperative computer programming language designed for scientific, engineering, business and systems programming applications...
. A third option provided remote job entry
Remote Job Entry
Remote job entry is the term used to describe the process of sending jobs to Mainframe computers from remote workstations, and by extension the process of receiving output from mainframe jobs at a remote workstation....
(RJE) features allowing users to submit JCL
Job Control Language
Job Control Language is a scripting language used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem....
JOB Stream
Job stream
In an IBM mainframe, the job stream is the path of execution that a job follows. The JCL and any data submitted with it form the job stream. There can be multiple EXEC and DD statements in a job stream if a job involves more than one program....
s for batch processing. A fourth option was called control mode. Normally, only the system operator would be permitted to use control mode. The available features in control mode included:
- Send a message to an individual user or all users.
- Clobber (today it would be called re-boot) a specific user's virtual CPS machine.
- Monitor the activity of an individual user.
- Terminate the entire CPS system.
CPS provided a highly interactive user experience. It accomplished this by giving an immediate syntax error
Syntax error
In computer science, a syntax error refers to an error in the syntax of a sequence of characters or tokens that is intended to be written in a particular programming language....
(when necessary) as soon as each line of a program was entered.
CPS was also offered with a firmware-assisted interpreter, on the System/360
System/360
The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
Model 50, only, but few Model 50 installations elected to install this RPQ. This RPQ executed the EVAL function of CPS's programming stack using a firmware assist.
The IBM-released version of CPS was designed to run on the IBM 1050
IBM 1050
IBM 1050 Data Communications System is a computer terminal subsystem to send data to and receive data from another 1050 subsystem or IBM computer in the IBM 1400, IBM 7000 or System/360 series. It first became available in 1963 and was used widely during the 1960s.-General:IBM 1050 Data...
terminal and the IBM 2741
IBM 2741
The IBM 2741 was a printing computer terminal introduced in 1965.It combined a ruggedized Selectric typewriter mechanism with IBM SLT electronics and an RS-232-C serial interface. It operated at about 14.1 characters per second with a data rate of 134.5 bits/second...
terminal with the "break feature". User groups later added support 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...
terminal.
CPS support for the IBM 2741
IBM 2741
The IBM 2741 was a printing computer terminal introduced in 1965.It combined a ruggedized Selectric typewriter mechanism with IBM SLT electronics and an RS-232-C serial interface. It operated at about 14.1 characters per second with a data rate of 134.5 bits/second...
"break feature" most likely influenced the eventual user group support for the "break feature" and the IBM 1050 terminal on ATS/360
IBM Administrative Terminal System
The IBM Administrative Terminal System, also known as ATS/360, was an IBM contributed program which provided, for the end-user customer of IBM System/360 systems, a system which was quite similar to the proprietary IBM Service Bureau Corporation product which ran on IBM 1440 systems or on IBM...
, as many IBM customers which operated CPS also operated ATS/360.
CPS was ultimately superseded by TSO
Time Sharing Option
In computing, Time Sharing Option is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 , MVS, OS/390, and z/OS.- Overview :TSO fulfills a similar purpose to Unix login sessions...
. An IBM program product was offered which provided limited CPS functionality under TSO
Time Sharing Option
In computing, Time Sharing Option is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 , MVS, OS/390, and z/OS.- Overview :TSO fulfills a similar purpose to Unix login sessions...
, intended mainly as a "bridge" between CPS and TSO
Time Sharing Option
In computing, Time Sharing Option is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 , MVS, OS/390, and z/OS.- Overview :TSO fulfills a similar purpose to Unix login sessions...
.