MMTTY Accessibility for
Blind and Vision-Impaired Hams


   MMTTY is a popular digital modem program for the RTTY digital text mode. This article reviews the accessibility of MMTTY for screen reader users and for visually impaired hams who use a computer screen.


   MMTTY is freeware developed by Makato Mori, JE3HHT, and distributed via the HamSoft Web site.

User Interface

   The user interface might appear overcomplicated at first, because MMTTY is also designed as a tool for experimentation by software developers. For example, three software-defined modulator options are included. Fortunately, the Basic Operation section of the Help Menu is written for beginners, and the program is not difficult to use. The manual also includes basic explanations about using RTTY.

   The MMTTY Main Display (Figure 1) is organized vertically in sections. Starting from the top they are Main Menu, Control Panel, Logging Menu, Receive Window, Transmit Menu, and Transmit Window.

Figure 1.  MMTTY Main Display



   The Main Display dimensions are adjustable up to full screen size. Height and width are independently variable by dragging the edges of the window. All of the contents enlarge as the size of the window is increased.

   The relative size of the Control Panel in the Main Display is also adjustable (View Menu → Control Panel Size).

   System font/style/size options are in the Misc Tab of the Setup Menu (Option Menu → Setup MMTTY → Misc Tab).

   High contrast color options for backgrounds and text are in the Font/Window Tab (Option Menu → Setup MMTTY → Font/Window Tab). The REF button opens font/style/size options for received and transmitted text.

Screen Reader Access

   All controls necessary to operate MMTTY are accessible with a screen reader. Every macro has a keyboard shortcut, and there is a well-organized system for customizing keyboard shortcuts for other functions.

   Default keyboard shortcuts include F9 to start transmitting and F8 to stop. ALT-C places a cursor in the Call Sign box, so you can type the contact ID for use in macros and for entry into the MMTTY log.

   The Control panel in the Main Display is not directly accessible with a screen reader, but that is not a problem. The macros in the panel all have keyboard shortcuts, and the controls are accessible via menus.

   Access to items in the Setup screens is circuitous, but not difficult. TAB moves among items in the screens, although not in the order of the visual display. The name of each item is spoken along with instructions for changing the setting. Locating the row of tabs in the Setup screen requires a few keystrokes:  TAB until the name of the Tab screen is spoken, followed by the instruction to CONTROL-TAB to the one you want.

   For example, to select the sound card connections:  ALT-O opens the Options menu. UP ARROW selects "Setup MMTTY." ENTER opens one of the Tab screens. TAB until you hear the name of the screen. CONTROL-TAB until "Sound Card Tab" is spoken, and ENTER. Items in the Sound Card screen are spoken with instructions for making selections. Finally, TAB to the OK button and ENTER.

Text to Speech

   The short transmissions used in RTTY contests and DXing make it possible to use a screen reader to read text received with MMTTY. Text to speech is covered in a separate article.


   Transmitting does not change the position of the screen reader cursor. For example, after you type in the Transmit Text Window or use keyboard shortcuts to launch macros, the reader cursor remains in place to read the next message.

For More Information

   MMTTY Text to Speech.


   MMTTY is accessible to screen reader users. RTTY transmissions during contests and DXing are short, making it possible to use a screen reader to read text received with MMTTY.


   Thanks to Bob, K3UL, for pointing out that MMTTY is accessible using the mouse control keys of a screen reader. Thanks also to Brian, W1BLS, for his generous help.

Author Information

   Peter DeNeef, AE7PD, is an Extra Class amateur radio operator in the U.S. This Web site has no ads or conflicts of interest."
Email:  HamRadioAndVision "at" gmail "dot" com.


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