GDSX Manual

Overview of GDSX
Extended General Device Support (GDSX) Manual–134303
1-3
GDSX Architecture
This figure shows a business-oriented Pathway/TS application interfacing with GDSX.
GDSX interfaces with an I/O process that handles the lower levels of the communication
protocol. High-level communication functions, such as screen presentation and line
management, are handled by GDSX USCODE. In general, the I/O process can be any
access method provided by Tandem or any user-supplied process. In fact, several access
methods can be supported by a LINE^HANDLER.
The GDSX process has two parts, TSCODE and USCODE. TSCODE, the unshaded
part of the GDSX process in Figure 1-4, provides generic services that help you create a
multithreaded, fault-tolerant process. The TSCODE kernel provides coordination
among all components of GDSX. The SPI/SCF interface provides the capability to use
SCF or other applications to manage devices and lines opened by GDSX.
USCODE consists of a number of procedures, called user exits, that are called by
TSCODE to handle data manipulation, protocol conversion, and/or message routing.
Figure 1-4. Application With GDSX and Pathway/TS
$0
Event
Collector
SPI/SCF
Service Routines
(Pseudo Calls)
(Utility Routines)
USCODE
Kernel
GDSX Process
Pathway/TS
TCP
3270
Run Unit
6530 or
IDS or
POBJ
File
TACL
Macros or User
Application
SCF
Conversational
Control
Event
Report
Management
Programming
Interfaces
IOP
(such as
CP6100)
Communication
Line
CDT020
User's Business Program
(SCREEN COBOL)