GDSX (Extended General Device Support) Manual

Overview of GDSX

Extended General Device Support (GDSX) Manual—529931-001

1-12

Indirect Terminal Access

the I/O process. When the I/O completes, the message is picked up by the

DEVICE^HANDLER task and passed back to the requester.

This type of direct interface between DEVICE^HANDLER tasks and I/O processes

requires the terminal to have a unique Guardian file name that can be opened directly

by TSCODE. Some access methods that support this kind of direct access by

Pathway/iTS are AM3270, ASYNC TERMPROCESS, X25AM, and CSS ASYNC

(6100). Each of these access methods requires a two-part file name for the device,

except ASYNC TERMPROCESS, which requires a one-part file name.

The following are examples of applications that can be handled with this type of

environment:

•

Accepting or initiating connections in X25AM

•

A two-step read in AM3270

•

Control-sequence translation for a nonsupported terminal, for example, the VT100

Indirect Terminal Access

There are applications, however, that involve shared data communication facilities

where the line (or message switching process) has a Guardian file name, but the

Figure 1-6. GDSX Without a LINE^HANDLER

$GDS

D^H Task

Pseudo-

$RECEIVE File

Pseudo-

$RECEIVE File

Requester

$RECEIVE

VST006.vsd