Guardian Application Conversion Guide

Converting Basic Elements of a TAL Program
Converting TAL Applications
3–2 096047 Tandem Computers Incorporated
Converting Basic
Elements of a TAL
Program
This subsection describes conversion that applies to all TAL programs you need to
convert to run under the D-series operating system, irrespective of what the program
does. Later subsections describe how to convert specific actions that your program
might take.
This subsection discusses the following topics:
Using source declarations from the EXTDECS file
Using source declarations from the ZSYSTAL file
Declaring and using variables for high PINs, file system error numbers, file names,
and process identifiers
Running the TAL compiler
Figure 3-1 shows a typical application. The box shows which processes this part of the
conversion applies to. Converting basic elements of a TAL program applies to both of
these processes.
Figure 3-1. Converting Basic Elements of a TAL Program
$SRV
$REQ
TAL Requester
Process
TAL Server
Process
TACL
Using the EXTDECS
Declarations
Your existing program should use the SOURCE compiler directive to specify the
Guardian procedure declarations in the $SYSTEM.SYSTEM.EXTDECS0 file. For
example, this SOURCE directive specifies C-series procedures:
?SOURCE $SYSTEM.SYSTEM.EXTDECS0 (OPEN,
? READX,
? WRITEX,
? CLOSE)