Summary
Currently, Tera Term allows controlling RTS and DTR lines only via TTL macros (setrts and setdtr) or through hardware flow control options. There is no way to toggle these lines manually from the graphical user interface (GUI).

Problem
When working with serial devices (e.g., embedded boards, modems, or programmers), users often need to manually assert or deassert RTS and DTR lines to reset, boot, or signal external hardware. Using macros for this purpose is inconvenient for quick manual testing.

Suggested solution
Add a simple GUI control (e.g., in the Setup → Serial port… dialog or in the Control menu) to manually toggle RTS and DTR lines:

• Checkboxes or toggle buttons labeled “RTS” and “DTR”.
• Visual indication of current state (on/off).
• Option to keep them fixed or revert to automatic control when hardware flow control is enabled.

Benefits

• Easier manual testing and debugging of hardware interfaces.
• Removes the need to write or run macros for basic control.
• Improves usability and parity with similar serial terminal tools.

Thank you for considering this feature!