Browse Prior Art Database

Migration of OS/2 Presentation Manager Programs to AIX via a Bridge

IP.com Disclosure Number: IPCOM000106741D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 81K

Publishing Venue

IBM

Related People

Preston, G: AUTHOR

Abstract

Described is a mapping layer to enable low cost porting of OS/2* PM programs to run on AIX. It avoids a rewrite of program to native Graphical Users Interface (GUI), Application Program Interface (API) or to third party common GUI. Reduced are development costs without external dependencies or charges. The code is designed for expansion to other Presentation Manager (PM) APIs not currently supported.

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Migration of OS/2 Presentation Manager Programs to AIX via a Bridge

      Described is a mapping layer to enable low cost porting of
OS/2* PM programs to run on AIX.  It avoids a rewrite of program to
native Graphical Users Interface (GUI), Application Program Interface
(API) or to third party common GUI.  Reduced are development costs
without external dependencies or charges.  The code is designed for
expansion to other Presentation Manager (PM) APIs not currently
supported.

      A problem existed when a program developed to run under OS/2 PM
system on PS2 hardware necessitated a similar and compatible
equivalent program for the AIX system on RS/6000* hardware.  A common
source code for both systems was desirable.  The following technique
resulted.  Disclosed is a technique and programs for the migration to
AIX of complex windowed applications written in C for OS/2
Presentation Manager.  The AIX system includes X-Windows and Motif,
and runs on RS/6000 hardware.  The technique is to use a "Bridge
Layer" to emulate the OS/2 and PM system functions using AIX.
Migration consists of:

1.  The application program is changed to initialize the Bridge.

2.  The PM Resource files, defining menus, dialogs, accelerator keys,
    and screen text, are recoded using Motif User Interface Language
    (UIL).

3.  The C and UIL source is compiled for the RS/6000 machine with
    changes to correct for differences in C dialects.  Special
    versions of the OS/2 PM header files are needed.  The changes are
    minor, but Bridge definition files are included.

4.  The application is linked with the Bridge Layer and the
    appropriate system libraries.

5.  Minor changes may be needed in the C source for:  differences in
    windowing conventions and styles; use of common interchange file
    formats and differences in file system naming.

      The Bridge Layer has the advantages of an existing OS/2 PM
program needing little change; the resulting common version can be
shared by OS/2 and AIX.  Many functions in OS/2 PM and IAX X-Windows
are similar, so the Bridge can be relatively simple.  Development
time and cost is reduced compared with alternatives.

      The Bridge Layer emulates most OS/2 and PM functions, using a
combination of logic in the Bridge Layer, cal...