SNAX/HLS Application Programming Manual

Application Prototyping and Simulation (APS) System
6–2 104707 Tandem Computers Incorporated
are unavailable, a modem eliminator can be used to loop back the $SNAP to the
$SNAT line. Such a configuration allows APS testing without an actual IBM
product.
The APS Pathway requester sends screens to a Tandem 6520 or 6530 terminal (not
shown).
The figure shows that the SNAX/HLS process must be running on the same node
as the SNAX lines. A Pathway TCP running the APS requester can be remotely
located in an Expand network.
HLSCOM is used for status inquiry during application debugging.
Preparing the Environment Before APS sessions can be established, the SNAX/HLS environment must be defined
and operating (see the SNAX/HLS Configuration and Control Manual for information on
operating SNAX/HLS). Also, the Pathway environment for APS must be defined and
operating. HLSRUN (a sample TACL macro illustrated in the SNAX/HLS
Configuration and Control Manual) is useful in starting the APS environment.
The examples in this section assume two APS terminals communicating with one
another through SNAX/HLS in a loop-back environment. To practice using APS,
three terminals are recommended: two for APS screens and one for HLSCOM
displays. It helps to study HLSCOM status displays after the execution of each
SNAX/HLS verb, especially at the beginning. Be prepared to make frequent reference
to the verb descriptions in Section 5, “SNAX/HLS Verbs” and to the listing of your
installation’s Resource Definition Table (RDT), described in the SNAX/HLS
Configuration and Control Manual.