Guardian Application Conversion Guide

2 Conversion Concepts
096047 Tandem Computers Incorporated 2–1
This section describes the major concepts involved in converting an application to
make use of the D-series enhancements. Specifically, this section describes:
The use of the new Guardian procedures
The new file-name format
New process identifiers
New system messages
Performance improvements for I/O operations
New Distributed Systems Management (DSM) tokens
New file-system error numbers and error lists
New object-file attributes
Conversion considerations related to the Common Run-time Environment (CRE)
New Guardian
Procedures
The D-series operating Guardian has many new user-accessible Guardian procedures.
However, to ensure compatibility with unconverted applications, Tandem provides
these new procedures in addition to the existing C-series procedures.
The D-series operating system does not include any new sequential I/O (SIO)
procedures. The SET^FILE, CHECK^FILE, and OPEN^FILE procedures (and their
LITERAL and DEFINE declarations) have been modified, but other SIO procedures are
unchanged.
Tandem provides declarations for many of the options and structures used as
parameters to the new Guardian procedures. Tandem uses the ZSYSDDL file to
generate the ZSYSTAL, ZSYSCOB, ZSYSC, ZSYSPAS , and ZSYSTACL files for TAL,
COBOL85, C, Pascal, and TACL applications, respectively. There is no equivalent file
for TACL programs. To use the ZSYSDDL declarations, include the appropriate file
(or sections of the file) in your source code.
This subsection describes in general the characteristics of the new procedures. For
information about each procedure, refer to the Guardian Procedure Calls Reference
Manual.
Note This guide uses the term D-series Guardian procedure to indicate a Guardian procedure that is new in
the D-series release. The term C-series Guardian procedure is used to refer to a C-series-compatible
Guardian procedure that can be called on either a D-series system or a C-series system.