Pathway/iTS SCREEN COBOL Reference Manual (G06.24+, H06.03+, Pathway/iTS 1.0+)

SCREEN COBOL Source Program
Compaq NonStop™ Pathway/iTS SCREEN COBOL Reference Manual—426750-001
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Block Mode Program
Block Mode Program
To execute in block mode, a SCREEN COBOL program must be communicating with a
block mode terminal. The screen definitions for any SCREEN COBOL program are
restricted by the characteristics of the specific type of terminal on which your program
runs.
A SCREEN COBOL program running in block mode performs as follows:
•
Recognizes a specific terminal type
•
Displays a full screen of information on the terminal
•
Accepts data entered from the terminal one screen at a time
•
Recognizes function keys and associates each with a particular function (for
example, pressing the F1 function key might be associated with exiting from a
screen)
Conversational Mode Program
A SCREEN COBOL program written for conversational mode operation can run on
either a block mode terminal or a conversational mode terminal. Once a program is
specified as conversational, that program performs according to the restrictions for a
conversational terminal regardless of the type of terminal on which the program runs.
A SCREEN COBOL program running in conversational mode performs as follows:
•
Displays information on the terminal during a DISPLAY statement, one line at a
time
•
Accepts data entered from the terminal, one line at a time
•
Responds to a set of input-control characters when the terminal is enabled to accept
data
•
Recognizes only keyboard characters, carriage return, and line feed (not function
keys)
•
Restricts the display field attributes to BELL and HIDDEN
Intelligent Mode Program
A SCREEN COBOL program running in intelligent mode does not control how data
appears to the intelligent device nor does it perform any other device-dependent
functions. It is the responsibility of the intelligent device to read and process messages
sent by the SCREEN COBOL program and to reply in a format accessible to the
program.
A program that communicates with an intelligent device uses a Message Section instead
of a Screen Section. It describes data to be sent to or received from the intelligent
device in the Message Section. The program can also send data directly from Working-
Storage, bypassing the Message Section.