Pathway/iTS TCP and Terminal Programming Guide

Introduction to TCP and Terminal Application
Programming
Compaq NonStop™ Pathway/iTS TCP and Terminal Programming Guide—426751-001
1-9
Requesters
multithreaded interface to terminals or intelligent devices. Finally, they provide support
for both context-free and context-sensitive servers.
Pathsend requesters are described in the NonStop™ TS/MP Pathsend and Server
Programming Manual.
SCREEN COBOL Requesters
SCREEN COBOL requesters, which are compiled by the SCREEN COBOL compiler
and then interpreted and executed by the terminal control process (TCP), provide ease of
programming if you need to handle large numbers of terminals or intelligent devices or
if you need screen-presentation services. The TCP and the SCREEN COBOL language
produce a high-quality, manageable application. The TCP provides multithreading of
requesters, fault tolerance, terminal device configuration, and operations management so
that you do not need to program these features in your application.
The TCP provides the following features:
•
Fault tolerance (when used in combination with TMF)
•
Automatic retry of I/O operations to a server process if the primary process of a
server process pair fails
•
Transaction protection through TMF
•
Multithreading
•
Interpretation of compiled pseudocode for programs written in the SCREEN
COBOL language, which offers a simple single-threaded programming environment
and a screen management system to drive IBM 3270 terminals and the 6530 family
of terminals (652x series, 653x series, and 654x series)
•
Special syntax to facilitate message assembly, disassembly, and processing
(Pathway intelligent device support, or IDS)
•
Access to server classes
•
Unsolicited message processing (UMP) support
•
Management interfaces (the PATHCOM process and the Subsystem Programmatic
Interface, or SPI) for TCP configuration and management, terminal configuration
and management, process management, error logging, and so on
You can use an Extended General Device Support (GDSX) process as a front-end
process to the TCP and SCREEN COBOL requesters to communicate with devices not
directly supported by the TCP. Use of the GDSX product is described in the Extended
General Device Support (GDSX) Manual.