Guardian Application Conversion Guide

About This Guide
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This guide describes how to convert a TAL, COBOL85, C, or Pascal application or a
Tandem Advanced Command Language (TACL) program to use the extended
features of the D-series operating system.
Audience This guide is intended for an application programmer who is converting an
application. The reader should be familiar with:
The language (TAL, COBOL85, C, Pascal, or TACL) used for the application
The Guardian programmatic interface, if the application calls Guardian
procedures or reads system messages from $RECEIVE
The Tandem requester-server approach to application programming, if the
application is a requester or a server
How to Use This Guide This guide is designed to help application programmers who want to convert their
programs to take advantage of the higher limits of the D-series operating system. It is
published as part of the D20 release, but there is more than one way to migrate to D20.
You might be migrating to D20 from a C-series release. In that case, this guide
provides you with the information necessary to convert your applications as you
migrate from a C-series system to a D-series system.
You might be migrating to D20 from the D10 release. In that case, your
applications already run successfully on a D-series system, and you might already
have converted them to take advantage of some or all of the higher limits of the
D-series operating system. This guide will assist you in converting any parts of
your application that have not already been converted and that you want to
convert at this time.
There are only a few things to convert at D20 that are new since D10. See “New
and Changed Information” at the beginning of this guide.
You might also be migrating to D20 running on a TNS/R system. Because TNS/R
systems were supported by C-series operating systems beginning at C30.06, you
might be coming from a TNS/R system already; in that case, there should be few
changes specific to TNS/R systems that you need to make. See “New and
Changed Information” at the beginning of this guide. If you are migrating from a
TNS system, however, you should read Section 9, “Converting to TNS/R
Systems.”
Organization This guide covers these topics:
Section 1 explains why Tandem developed the D-series operating system and
summarizes the differences between a C-series and D-series operating system that
affect an application programmer. It also provides an approach to converting an
application and directs the reader in how to find the required information in the rest of
the guide.