Gradually the child is introduced to more language and eventually the transparency can be removed so that all 32 messages are visible. The learning curve is slow but steady. Speed is slow but accurate. Excellent switch control with thumb on right hand, high cognitive and has some functional literacy and sight vocabulary skills. Does not want to spell due to speed and fatigue.
Vision is fine.
Single switch Morse code using thumb on right hand and a ZYGO Lolly switch. The Green Macaw is used with 64 and 128 key patterns. For this user, the learning curve is fast and mostly self taught. This user is introduced to Morse code inputting method using a 64 location overlay initially. Overlay is word based and generative leaving some message locations blank to aide in visual location of icons.