Morse code as an accessibility tool: typing with one or two keys
Morse code suits typing with one or two keys because every letter, figure and punctuation mark is made of just two signals, short and long, separated by pauses. With one switch, a short press is a dit and a long press is a dah. With two switches, one makes dits and the other makes dahs. Either way you choose each character directly, instead of waiting for a highlight to reach it, and with practice the patterns can become automatic.
This post looks at why that works, how one switch and two switches differ, what macOS itself offers for switch access, and how to make Morse comfortable if you want to try it.
Why two signals are enough
International Morse code needs only two kinds of element and three lengths of silence. That is enough for the whole alphabet, the ten figures and the common punctuation marks, and none of the letters is long:
| Presses | Letters |
|---|---|
| 1 | E, T |
| 2 | A, I, M, N |
| 3 | D, G, K, O, R, S, U, W |
| 4 | B, C, F, H, J, L, P, Q, V, X, Y, Z |
| 5 | The figures 0 to 9 |
The shortest codes went to the letters English uses most: E is . and T is -. A common word like THE is - .... ., six presses in all. Why E is one dit tells that part of the story.
Two other things make Morse a good fit for a switch. You do not need to see anything to send it, so your eyes stay on the text you are writing. And it is a single standard: once you know it, it works the same way with any key, switch or software that reads it.
One switch or two
The difference between the two setups is what tells a dit from a dah.
One switch: length decides. A short press is a dit, a press about three times as long is a dah. The pauses do the rest: a short pause between presses keeps you inside a letter, a longer one ends the letter, and a longer one again ends the word. This needs only one reliable movement, but it asks for fairly even timing. If your short presses sometimes run long, a dit can be read as a dah.
Two switches: which switch decides. One switch is the dit, the other the dah, so the length of each press matters far less. Only the pauses still need timing, to mark the ends of letters and words. That is more forgiving of uneven presses, but it needs two movements you can make independently, such as two fingers, a hand and a foot, or left and right.
Radio operators use two-switch keys too, called paddles, but with a twist: holding a paddle repeats its element, and squeezing both alternates dits and dahs, timed by a keyer. That is iambic keying, explained in iambic keying: mode A vs mode B. Some two-switch setups instead make one element per press, with nothing repeated while you hold.
| One switch | Two switches | |
|---|---|---|
| What makes a dah | A longer press | The second switch |
| Timing needed | Press length and pauses | Pauses only |
| Movements needed | One | Two, independently |
| Worth trying when | You have one dependable movement | Your press lengths vary |
Morse compared with scanning
The other common way to type with a switch is scanning. A highlight steps through the items on screen, or through the keys of an on-screen keyboard, and you press the switch when it reaches the one you want. Scanning needs nothing memorized, and it works for clicking menus and buttons as well as for text. Its pace is set by the scan: every choice means waiting for the highlight to arrive.
Morse is the opposite trade. You must learn the code first, which takes regular practice. After that, the pace is yours: E is one press whenever you want it, and nothing moves on the screen. The two do not exclude each other. Scanning can handle menus and the pointer while Morse handles the writing.
What macOS offers for switch access
macOS has several features for people who use switches or cannot use a standard keyboard comfortably, all in System Settings, Accessibility:
- Switch Control lets you control the Mac with one or more switches: a keyboard key, a mouse button, a gamepad button or a dedicated switch device. It works by scanning, and it includes an on-screen keyboard panel for typing.
- Accessibility Keyboard is an on-screen keyboard for typing without a hardware keyboard. With Dwell, holding the pointer still on a key for a set time triggers it.
- Voice Control lets you operate the Mac and dictate text by voice.
- Sticky Keys lets you press modifier keys one at a time for a shortcut, and Slow Keys adds a delay before a key press is accepted.
None of these reads Morse, and macOS does not include a Morse input method. To type in Morse on a Mac you need separate software that reads a key and turns your dits and dahs into characters.
If you rely on switch access, start with these built-in features, and talk to an occupational therapist or an assistive technology specialist. They can help you choose switches, place them where a movement is easy and repeatable, and set up access that fits you. Their advice matters more than any software choice.
Making Morse comfortable with a switch
- Choose a slow speed and keep it. Comfort matters more than speed. At 5 words per minute a dit lasts 240 milliseconds and a dah 720, which leaves plenty of room to tell them apart.
- Be generous with gaps. A letter gap is three times a dit and a word gap seven times. Gaps that are too short merge letters: A
.-followed too quickly by N-.reads as P.--.. - Learn in stages. Start with a handful of common letters, such as E, T, A, N, I and S, and build words from them before adding more. How to learn Morse code sets out a plan.
- Learn the correction. The error signal is eight dits,
......... Find out what your software does with it before you rely on it. - Keep sessions short. Short, regular sessions suit learning Morse better than long, rare ones.
Trying one-key typing on a Mac
Dot & Dash is a Mac app for learning and keying Morse. It is not assistive technology or an accessibility device, and it makes no promise to suit any particular need. Its Type Anywhere feature keys Morse into any app, which some people may find useful: switch it on from its menu bar item, allow Accessibility when macOS asks, then key on Right Option, or on Right Command, Right Control, Left Option, Left Command or Left Control if you choose. A short press is a dit, a longer one a dah, and each character is typed into the app in front as you finish it. With the straight key, Dot & Dash reads your keying at your own speed; paddles, in iambic mode A or B, use two of those keys. The error signal deletes only the last word it typed, never your own text. How to type Morse code into any app on a Mac walks through the setup.
Questions
Can you type with Morse code using one key?
Yes. A short press is a dit and a press about three times as long is a dah, and pauses mark the ends of letters and words. Every letter needs at most four presses and every figure five.
Is one switch or two better for Morse?
It depends on your movements. One switch needs only one dependable movement but fairly even press lengths; two switches, one for dits and one for dahs, are more forgiving of uneven presses but need two independent movements.
Does macOS have a Morse code keyboard?
macOS does not include a Morse input method. It offers Switch Control, the Accessibility Keyboard, Voice Control, Sticky Keys and Slow Keys in System Settings, Accessibility, but none of them reads Morse, so typing in Morse needs separate software.
Is Morse faster than scanning?
It can be, once learned, because you choose each character directly instead of waiting for a highlight. But Morse takes practice to learn, while scanning works from the first day, and which suits you depends on your movements and needs; an occupational therapist can help you weigh them.