What viewport and display management features does SMG$ provide?

SMG$ offers comprehensive viewport and display management capabilities including: • Virtual display creation and manipulation with SMG$CREATE_VIRTUAL_DISPLAY • Pasteboard management for organizing multiple display areas • Viewport creation and control with SMG$CREATE_VIEWPORT and SMG$CHANGE_VIEWPORT • Display layering and pasting operations for complex screen layouts • Advanced text rendering with multiple character set support • Cursor positioning and movement control across display regions • Screen update optimization through display update sessions • Rectangle and line drawing for graphical text applications

What keyboard input and interaction capabilities does SMG$ support?

VX/SMG delivers keyboard input and interaction through virtual keyboard management and input processing routines. It supports function key handling, escape sequences (SMG$ALLOW_ESCAPE) and programmable key definitions via SMG$DEFINE_KEY, SMG$NAME_TO_KEYCODE and SMG$KEYCODE_TO_NAME. The system provides both immediate keystroke reading with SMG$READ_KEYSTROKE and full line input with SMG$READ_STRING, and SMG$CANCEL_INPUT cancels pending input requests.

Our OpenVMS application makes use of multiple System Services. How do you support that?

Sector7 has an extensive library of these services running on Linux to perform the same functions as on OpenVMS. our language conversion tools will adapt the arguments in the procedure API to work with this library. For instance, VX/COBOL or VX/FORTRAN etc will transform the argument passed BY DESCRIPTOR to a method that will work on Linux. When the code is compiled on Linux, the compiled objects are linked with the Sector7 library of system services and the program executes on Linux just as it does on OpenVMS, making full use of the various system services. The critical point here is that there is no need to touch the original source code, the Sector7 tools do all the work.

Which OpenVMS runtime libraries does VX/RT support?

VX/RT provides call-compatible implementations of the major OpenVMS runtime libraries, including LIB$ (general routines), STR$ (string), MTH$ (math), OTS$ (data conversion), and SYS$ (system interface), along with language runtimes such as BAS$, COB$, FOR$, and PAS$. Each family has its own detailed reference page under /technical/.

VX/SMG – SMG

Description

VX/SMG is a full implementation of DEC’s VMS/OpenVMS Screen Management Service (SMG$) for Linux and Windows. It provides a call-compatible interface for all 3GL languages, allowing applications that use SMG$ routines on VMS to function identically on modern platforms.

VX/SMG ensures that user programs remain independent of the physical display devices, offering virtual displays, pasteboards, viewports, and advanced terminal rendering features.

Key Features

• Full SMG$ API Compatibility – Implements all VMS SMG$ calls without modification.

• Terminal Independence – Works with VT100, VT220, VTxxx ANSI, AT386, and DECterm.

• Advanced Window Management – Supports pasteboards, multiple windows, overlapping views.

• Extended Rendering Features – Includes double-wide characters, scrolling regions, and cursor control.

• Seamless Migration – Works without modifying original VMS SMG applications.

• Performance Optimized – Implements a native C-based terminal driver, bypassing curses, termcap, and terminfo for high-speed execution.

VX/SMG Features and Compatibility

VX/SMG retains all core functionalities of VMS/OpenVMS SMG while enabling enhanced flexibility in modern environments.
‍

Feature	Description
Virtual Displays	Allows independent screen areas for applications.
Pasteboards	Provides a logical screen buffer that manages multiple displays.
Viewports	Enables scrollable window views into larger virtual displays.
Double-Wide Characters	Supports double-wide and double-high text rendering.
Terminal Independence	Compatible with VT100, VT220, VTxxx, and DECterm.
Cursor & Text Control	Supports positioning, deletion, insertion, and erasure of text.

VX/SMG enables seamless execution of legacy VMS SMG applications while enhancing performance and portability.

VX/SMG Functionality & Terminal Support

Multiple Screen Regions

VX/SMG allows applications to create multiple independent windows using virtual displays, each of which can be dynamically moved, updated, or hidden.

• Pasteboards – Act as logical containers for multiple screen areas.

• Viewports – Provide zoomed-in windows into larger virtual displays.

• Occlusion Checking – Ensures correct layering of overlapping windows.

Direct Terminal Access

VX/SMG does not rely on curses, termcap, or terminfo, instead using a native C-based driver for:

• Faster rendering

• Hardware scrolling support

• More efficient screen updates

Supported terminals include:

✅ VT100, VT220, VTxxx ANSI

✅ AT386 and DECterm

VX/SMG screen running in a terminal — (TOLAS screen kindly donated by GSI Transcomm)

Windows version of above screen. WINSMG is now obsolete and will only be resurrected under pain of torture, imminent death or cash.

‍

‍

Example: Using Virtual Displays in VX/SMG

#include "vxsmg.h"

int main() {
    SMG$CREATE_VIRTUAL_DISPLAY(24, 80, &display_id);
    SMG$PASTE_VIRTUAL_DISPLAY(display_id, pasteboard_id, 1, 1, 0);
    SMG$PUT_LINE(display_id, "Welcome to VX/SMG!");
    SMG$DELETE_VIRTUAL_DISPLAY(display_id);
    return 0;
}

VX/SMG API Reference (SMG$ Functions)

VX/SMG fully implements the VMS SMG$ API, ensuring compatibility with existing applications.

‍

SMG$ API	Function
SMG$ALLOW_ESCAPE	Enables escape sequence handling in terminal input.
SMG$BEGIN_DISPLAY_UPDATE	Locks the display for batch updates.
SMG$BEGIN_PASTEBOARD_UPDATE	Begins an optimized pasteboard update session.
SMG$CANCEL_INPUT	Cancels pending input requests.
SMG$CHANGE_PBD_CHARACTERISTICS	Modifies pasteboard characteristics.
SMG$CHANGE_RENDITION	Changes text appearance (e.g., bold, underline).
SMG$CHANGE_VIEWPORT	Adjusts viewport dimensions.
SMG$CHANGE_VIRTUAL_DISPLAY	Modifies properties of a virtual display.
SMG$CHANGE_VIRTUAL_KEYBOARD	Alters keyboard settings.
SMG$CHECK_FOR_OCCLUSION	Determines if a display is occluded.
SMG$CONTROL_MODE	Configures display control modes.
SMG$COPY_VIRTUAL_DISPLAY	Duplicates a virtual display.
SMG$CREATE_MENU	Creates a menu interface.
SMG$CREATE_PASTEBOARD	Creates a logical screen buffer.
SMG$CREATE_VIEWPORT	Defines a viewport in the display.
SMG$CREATE_VIRTUAL_DISPLAY	Allocates a new virtual screen region.
SMG$CREATE_VIRTUAL_KEYBOARD	Creates a virtual keyboard.
SMG$CURSOR_COLUMN	Gets or sets the cursor column.
SMG$CURSOR_ROW	Gets or sets the cursor row.
SMG$DEFINE_KEY	Assigns a function to a key.
SMG$DELETE_CHARS	Removes characters from the display.
SMG$DELETE_LINE	Deletes a line of text.
SMG$DELETE_MENU	Removes a menu from memory.
SMG$DELETE_PASTEBOARD	Deletes a pasteboard.
SMG$DELETE_VIEWPORT	Removes a viewport from the display.
SMG$DELETE_VIRTUAL_DISPLAY	Removes a virtual display from memory.
SMG$CREATE_VIRTUAL_KEYBOARD	Creates a virtual keyboard.
SMG$CURSOR_COLUMN	Gets or sets the cursor column.
SMG$CURSOR_ROW	Gets or sets the cursor row.
SMG$DEFINE_KEY	Assigns a function to a key.
SMG$DELETE_CHARS	Removes characters from the display.
SMG$DELETE_LINE	Deletes a line of text.
SMG$DELETE_MENU	Removes a menu from memory.
SMG$DELETE_PASTEBOARD	Deletes a pasteboard.
SMG$DELETE_VIEWPORT	Removes a viewport from the display.
SMG$DELETE_VIRTUAL_DISPLAY	Removes a virtual display from memory.
SMG$DELETE_VIRTUAL_KEYBOARD	Removes a virtual keyboard.
SMG$DISABLE_BROADCAST_TRAPPING	Disables broadcast message trapping.
SMG$DRAW_CHAR	Draws a single character at the cursor position.
SMG$DRAW_CHARACTER	Renders a character at a specified position.
SMG$DRAW_LINE	Draws a line on the virtual display.
SMG$DRAW_RECTANGLE	Creates a rectangular shape on the display.
SMG$END_DISPLAY_UPDATE	Unlocks the display after batch updates.
SMG$END_PASTEBOARD_UPDATE	Ends an optimized pasteboard update session.
SMG$ERASE_CHARS	Erases specified characters from the display.
SMG$ERASE_COLUMN	Clears a column of text on the display.
SMG$ERASE_DISPLAY	Clears the entire display.
SMG$ERASE_LINE	Erases the current line from the display.
SMG$ERASE_PASTEBOARD	Clears all content from the pasteboard.
SMG$FIND_CURSOR_DISPLAY	Identifies which display contains the cursor.
SMG$FLUSH_BUFFER	Flushes output buffers to the terminal.
SMG$GET_BROADCAST_MESSAGE	Retrieves system broadcast messages.
SMG$GET_CHAR_AT_PHYSICAL_CURSOR	Gets the character at the cursor position.
SMG$GET_DISPLAY_ATTR	Retrieves display attributes of a virtual screen.
SMG$GET_KEYBOATD_ATTRIBUTES	Gets keyboard characteristics.
SMG$GET_PASTEBOARD_ATTRIBUTES	Retrieves pasteboard properties.
SMG$GET_PASTING_INFO	Fetches details on pasting order.
SMG$GET_TERM_DATA	Retrieves terminal configuration data.
SMG$GET_VIEWPORT_CHAR	Gets the character at viewport position.
SMG$HOME_CURSOR	Moves the cursor to the home position.
SMG$INIT_TERM_TABLE	Initializes the terminal information table.
SMG$INIT_TERM_TABLE_BY_TYPE	Initializes a terminal table by type.
SMG$INSERT_CHARS	Inserts characters at cursor position.
SMG$INSERT_LINE	Inserts a new line at cursor.
SMG$INVALIDATE_DISPLAY	Marks the display as needing refresh.
SMG$KEYCODE_TO_NAME	Converts a keycode to a name.
SMG$KEYPAD_MODE	Sets the keypad mode.
SMG$LABEL_BORDER	Adds a border label to a display.
SMG$LIST_PASTING_ORDER	Lists the pasting order of virtual displays.
SMG$LOAD_VIRTUAL_DISPLAY	Loads a virtual display into memory.
SMG$MOVE_TEXT	Moves text from one location to another.
SMG$MOVE_VIRTUAL_DISPLAY	Moves a virtual display on the screen.
SMG$NAME_TO_KEYCODE	Converts a key name to its keycode.
SMG$PASTE_VIRTUAL_DISPLAY	Adds a virtual display to the pasteboard.
SMG$POP_VIRTUAL_DISPLAY	Removes the topmost virtual display from the stack.
SMG$PRINT_PASTEBOARD	Prints the contents of the pasteboard.
SMG$PUT_CHARS	Writes characters to the virtual display.
SMG$PUT_CHARS_HIGHWIDE	Writes double-height, double-wide characters.
SMG$PUT_CHARS_MULTI	Writes multi-byte character strings.
SMG$PUT_CHARS_WIDE	Writes wide characters to the display.
SMG$PUT_LINE	Outputs a line of text to the display.
SMG$PUT_LINE_HIGHWIDE	Outputs a high-wide formatted line.
SMG$PUT_LINE_WIDE	Outputs a wide-character formatted line.
SMG$PUT_PASTEBOARD	Writes a pasteboard to the screen.
SMG$PUT_WITH_SCROLL	Outputs text with automatic scrolling.
SMG$READ_FROM_DISPLAY	Reads data from a virtual display.
SMG$READ_KEYSTROKE	Reads a keystroke from the input buffer.
SMG$READ_STRING	Reads a string of input from the user.
SMG$REPAINT_LINE	Repaints the specified line on the display.
SMG$REPAINT_SCREEN	Repaints the entire screen.
SMG$REPASTE_VIRTUAL_DISPLAY	Repastes a virtual display to the pasteboard.
SMG$RESTORE_PHYSICAL_SCREEN	Restores a previously saved physical screen.
SMG$RETURN_CURSOR_POS	Returns the current cursor position.
SMG$RING_BELL	Sounds the terminal bell.
SMG$SAVE_PHYSICAL_SCREEN	Saves the current physical screen state.
SMG$SAVE_VIRTUAL_DISPLAY	Saves a virtual display to memory.
SMG$SCROLL_DISPLAY_AREA	Scrolls a specified area of the display.
SMG$SCROLL_VIEWPORT	Scrolls within a viewport.
SMG$SELECT_FROM_MENU	Allows the user to select an item from a menu.
SMG$SET_BROADCAST_TRAPPING	Enables or disables broadcast message trapping.
SMG$SET_CURSOR_ABS	Sets the cursor position to absolute coordinates.
SMG$SET_CURSOR_MODE	Sets the cursor visibility and blink mode.
SMG$SET_CURSOR_REL	Moves the cursor relative to its current position.
SMG$SET_DISPLAY_SCROLL_REGION	Defines a scroll region within the display.
SMG$SET_KEYPAD_MODE	Sets the keypad operating mode.
SMG$SET_PHYSICAL_CURSOR	Sets the physical cursor position.
SMG$SET_TERM_CHARACTERISTICS	Modifies terminal characteristics.
SMG$UNPASTE_VIRTUAL_DISPLAY	Removes a virtual display from the pasteboard.

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

Conclusion

✅ 100% SMG$ API compatibility on Linux & Windows

✅ Full terminal control – pasteboards, virtual displays, viewports

✅ No changes needed – identical execution to OpenVMS SMG

✅ Seamless migration with Sector7’s VX/RT

✅ Supports VT-terminals, DECterm, and ANSI-emulation

✅ Optimized for performance – No reliance on termcap/curses

VX/SMG ensures that OpenVMS SMG-based applications function identically on Linux and Windows while enhancing performance and usability.