Saturday, April 14, 2018

Morse Codes for Computer Access

Morse code is a perfect method for a quadriplegic, someone with little or no ability to move. A person just needs to be able to activate a switch.
Many people with physical disabilities are not able to use a computer keyboard or mouse. This severely limits their access to the educational, recreational and career opportunities provided by computer technology. Morse code has long been recognized as an effective computer access method for people who are not able to use a keyboard or mouse.
Morse code systems use a binary input method that represents characters and commands as a series of dots and dashes. For example, a dot followed by a dash indicates the letter a, a dash followed by three dots represents b, etc. If a single switch is used for entering the code, a dash is differentiated from a dot by holding the switch closed for a longer period of time. In two-switch Morse code, one switch is used for entering dots while the other is used for dashes. Three-switch input is also available for people who cannot reliably control their movements. A variety of switches are available and most people can use Morse code, no matter what their disability. Morse code is quite efficient. Speeds of 15 to 30 words a minute are common and speeds in excess of 60 words per minute can be attained.
Morse code has a number of advantages over other alternate computer access strategies. It is usually faster, requires less fine motor control and is less likely to produce fatigue than other methods. Perhaps its most important advantage is its ability to become a sub-cognitive process. After using the code for a period of time, the Morse code user no longer thinks about the code they’re entering. This is the same process as is used by touch typists and it has a significant impact on speed, accuracy and the quality of the work being produced. Morse code is the only alternate access method that can become a sub-cognitive process.
*source: "Draft Development Specification: Morse Code Input System for the Windows 2000 Operating System", February 17, 1999
These are the morse codes I use to access the computer using a sip and puff pneumatic (air) switch connected to the AdapTek Interface Adap2U Adaptive Input Interface System. I've been using the Adap2U since 1994, unfortunately, it is no longer available. With the Adap2U I am able to enter every keyboard key, move the mouse and click the mouse buttons. Since the Adap2U is a hardware interface it can be used with any operating system. I have used it with every version of Windows (currently using Windows 10 Home 64-bit) and several versions of Linux.

I just started using a new morse code input device called Tandem Master aka Morse-2-USB controller. Using 2 switches (two head switches or sip and puff, for example) the user can input Morse codes for all keyboard keys, mouse the mouse (left, right, up, down) and click the mouse buttons. It is automatically recognized by any modern computer with a USB port. No additional software is needed to operate it.

In the Paralysis Resource Center video Hands-Free Computing, you can see how I use input Morse-type codes by using sip and puff.

I was also featured on the Korean TV program "Science 21" (view segment)

Note: Some of the codes shown here are not standard International Morse code. I have changed some codes to better suit my usage. Example: standard M is "--" which I use for backspace instead.

I have codes defined in two "groups" and use a code to switch between them. This enables me to reuse the same codes for different functions in different groups. A third code group contains codes that are always active, such as commands to switch between the other code groups.

Modifier keys (Shift, Control & Alt) release after the next code for a non-modifier key is sent. If a modifier key is needed to remain active for multiple keys then the hold/release code can be used to keep it active until the hold/release code is sent again.

To move the mouse pointer, send the code once for the direction (up/down/right/left) then the repeat code (a single sip). The mouse continues to move in that direction until either a single sip or puff will stop it. The standard mouse move is set to move 4 mickeys. When I need to be more precise I send the "mouse zoom" code which changes the mouse moves to 1 mickey.

A " · " is a sip and a " - " is a puff.

Alpha-Numeric Code Group

Mouse/Windows Code Group

Morse Code devices:

  • TandemMaster - converts the Morse-type Code (completely user-definable codes) to keystrokes and mouse movements. Works with any computer accepting an HID-compliant keyboard and mouse. Works with Android devices using an OTG cable.
  • Darci USB- Darci USB Keyboard and Mouse Emulator
  • Jouse3 - joystick-based mouse and keyboard alternative built-in Morse code capability.
  • Morse2Go project - a small, low-cost communication device for people struggling with speech and movement. Text can be keyed into the M2G using a finger, foot, head, or mouth switch. Words display on the TFT screen and are converted to audible speech so that another person can understand what is being communicated.
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