VX/FMS - OpenVMS Forms Management

Description

VX/FMS is a full implementation of DEC’s OpenVMS Forms Management System (FMS) for Linux and Windows. It provides an identical form management experience, ensuring seamless migration of VMS applications that rely on FDV$ APIs.

The VX/FMS compiler translates FMS mask description language into binary runtime files, allowing applications to retain their original behavior, formatting, and user interactions on modern platforms.

VX/FMS supports VT terminals, DECterm, and advanced text formatting while maintaining full compatibility with existing VMS FMS applications.

Key Features

• Identical API behavior – Implements all FDV$ APIs with the same arguments as OpenVMS FMS.

• Full Form Compilation – Converts FMS description files into binary runtime for Linux and Windows.

• Terminal compatibility – Supports VT100, VT220, DECterm, and ANSI-compatible consoles.

• User Action Routines (UARs) – Allows custom user-defined routines to execute during form events.

• Integration with Sector7 Migration Tools – Works with VX/RT, VX/RMS, and other Sector7 solutions.

VX/FMS Features and Compatibility

VX/FMS ensures that all core features of OpenVMS FMS are retained during migration, providing a 100% compatible environment.

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VX/FMS is designed to work as a standalone product or integrate seamlessly with VX/RT, Sector7’s VMS runtime for Linux and Windows.

VX/FMS Functionality & API Support

Terminal Compatibility

VX/FMS supports multiple terminal types, ensuring identical user interaction across platforms:

• VT100, VT220, and all compatible VT-series terminals

• DECterm under DECwindows

• ANSI-compatible terminal emulators for Linux

Example: Running FMS Forms on Linux

$ vxfms form_name

FMS Form Driver: Execution and Display

The Form Driver is the runtime component of VX/FMS, responsible for:

• Rendering FMS screens in VT-terminals & DECterm

• Handling user input, navigation, and validation

• Executing User Action Routines (UARs) for interactive events

VX/FMS does not rely on curses, termcap, or terminfo, ensuring direct compatibility with original VMS FMS behavior.

User Action Routines (UARs) & Interactive Forms

User Action Routines (UARs) are user-defined callback procedures triggered by form events. VX/FMS fully supports all UAR scenarios, including:

• Field completion events

• Help requests by terminal operators

• Function key interactions

• Screen refresh operations

Example: Defining a UAR in VX/FMS

void MyCustomUAR() {
    // Custom logic for form validation or user interactions
}
VXFMS.RegisterUAR(MyCustomUAR);

VX/FMS extends original FMS capabilities by allowing dynamic linking of external C++ functions, providing greater flexibility.

VX/FMS Forms Compiler

The VX/FMS Compiler translates FMS mask description language into runtime binary files, ensuring that VMS FMS applications execute identically on Linux and Windows.

Example: FMS Mask Description File

FORM screen_1
    FIELD username
    FIELD password
    BUTTON submit
END FORM

Compiled Output

class Screen1Form {
public:
    std::string username;
    std::string password;
    void Submit();
};

VX/FMS ensures that all form logic and attributes are preserved, maintaining identical behavior across platforms.

VX/FMS API Reference (FDV$ APIs)

VX/FMS implements the full VMS FMS FDV$ API set, ensuring full compatibility for migrated applications.

VX/FMS retains all FDV$ APIs required for seamless execution of legacy VMS applications.

Conclusion

✅ 100% FMS API Compatibility on Linux & Windows

✅ No functional changes required – perfect migration parity

✅ Seamless integration with VX/RT for full VMS emulation

✅ Supports VT-terminals, DECterm, and modern UI extensions

✅ Enables real-time User Action Routines (UARs)

VX/FMS is the only solution that enables seamless migration of OpenVMS FMS applications to Linux and Windows without modification.