Seamlessly Transition Your VMS Applications to Linux

VX/RT: Seamlessly Transition Your VMS Applications to Linux

When it comes to migrating complex VMS / OpenVMS applications to modern platforms like RedHat or SUSE Linux, Sector7’s VX/RT stands out as a critical toolset designed to make this transition as seamless as possible. VX/RT is a robust library of over 900 API functions, all developed in native C and C++, ensuring your applications retain their full functionality without the need for extensive recoding or re-engineering.

The strength of VX/RT lies in its meticulous compatibility. All APIs take the same arguments and formats as their VMS / OpenVMS equivalents, preserving file specifications, logicals, and even versioning behavior. This design allows your applications to run just as they did on VMS / OpenVMS, but now with the efficiency and flexibility of a Linux environment. No manual code changes are needed, which saves time and significantly reduces the risk of errors.

Preserving Functionality and Reducing Migration Complexity

The design philosophy of VX/RT is simple yet transformative: eliminate the need for laborious code modifications. Whether it’s converting file paths or mapping return codes, VX/RT handles these intricacies at runtime. For instance, a file operation like SYS$OPEN functions exactly as it does on VMS / OpenVMS, even returning familiar error codes such as RMS$_FNF if a file isn’t found. The FAB (File Access Block) structure remains unchanged, ensuring consistent behavior across platforms.

Beyond preserving API compatibility, VX/RT is also about seamless integration with your existing infrastructure. The toolkit includes essential components like VX/DCL and VX/RMS to manage command line operations and data access efficiently. Together, these toolkits provide a holistic migration solution that addresses the unique challenges of porting VMS / OpenVMS applications, from handling system calls to maintaining data integrity.

Handling Data and Language Differences

Migrating data is one of the most challenging aspects of moving from VMS to Linux, especially when dealing with RMS data structures and proprietary formats. Sector7’s VX/RMS provides an ODBC interface and full API support, ensuring your data remains accessible and functional in the new environment. It allows for concurrent data retrieval in a client-server mode and supports standard VMS structures like FAB, RAB, NAM, and XABs. Additionally, VX/DataX handles byte ordering and floating-point format conversion, making data transfer between VMS and Linux architectures seamless.

Language compatibility is another key hurdle. Many VMS applications are written in languages with VMS-specific extensions. VX/RT, paired with native compilers and language translators, bridges this gap. It ensures that your applications can be compiled, linked, and executed with minimal disruption, preserving your investment in custom code and reducing the need for extensive rewriting.

Advanced Features: ASTs, Timers, and More

For applications that rely on advanced VMS features like Asynchronous System Traps (ASTs) and timer mechanisms, VX/RT delivers full support. ASTs are crucial for many VMS applications, and VX/RT ensures they operate exactly as expected, including support for user, supervisor, executive, and kernel modes. Timers are equally robust, allowing multiple schedules and precise cancellations, mirroring the behavior of VMS / OpenVMS.

Memory management is another area where VX/RT excels. It faithfully replicates VMS memory management functions, including paged and zone-based allocation. While certain restrictions exist due to differences in memory architectures, VX/RT provides the essential capabilities your applications need. For example, global sections can be mapped to provide the same logical functions as VMS / OpenVMS 3GLs, maintaining the performance and stability of your applications.

Expanding Your Capabilities with VX/DCL and VX/CLI

Many VMS applications interact with DCL scripts for executing system-level operations. VX/DCL replicates the VMS / OpenVMS DCL shell on Linux, offering both standard command-line functionality and programmable API support. This means your applications can continue using DCL scripts without modification, and system functions can be executed with the same precision and reliability. VX/CLI extends this functionality by providing a command line interpreter and a definition compiler, ensuring complex command syntax is processed accurately.

VX/RT also supports VMS batch and print queue functionality, with over 100 DCL commands translated to work seamlessly on the new platform. The system ensures that event flags, a critical feature for synchronizing processes, function as expected, offering both local and global support for clustered operations.

Managing Logicals, Symbols, and More

Logicals and symbol tables are integral to VMS applications, and VX/RT provides full support for these features. The logical manager in VX/RT adheres to VMS rules for user and kernel mode logicals, and even extends functionality to integrate with Linux-style APIs. Symbols, unlike environment variables in Linux, are managed through IPC mechanisms, ensuring they are accessible across different programs and processes, just as they are on VMS / OpenVMS.

Memory management, event flag operations, and command line processing are all crucial aspects of VMS applications, and VX/RT replicates them with high fidelity. This allows your applications to perform complex tasks and maintain operational efficiency even after migration.

Conclusion: The VX/RT Advantage

VX/RT is more than just a migration tool; it’s a comprehensive solution that preserves your applications’ functionality while enabling them to thrive on modern Linux platforms. By eliminating the need for manual code changes and maintaining compatibility with essential VMS APIs, VX/RT provides a low-risk, high-reward migration path. Sector7’s expertise ensures that your organization can modernize its operations without sacrificing the reliability or performance of your legacy systems. Discover the VX/RT advantage and make your transition to Linux efficient, cost-effective, and seamless.