Kian Ryan was looking for a keyboard to allow one handed use while anticipating recovery from shoulder surgery. Various options in the marketplace were explored with the FrogPad keyboard being chosen as an example of might work best.
The FrogPad, released in 2002, relies on key frequency organised in a number of layers. The Buxton collection is a great resource on user interface devices, and contains an excellent entry on the FrogPad, including a link to the quick start guide and the manuals.
The FrogPad organises the most frequent alpha characters in the top layer, with the remaining alpha characters in a secondary layer.
FrogPad work on the basis that 83% of the most frequent characters are in the top layer. “HELLO, WORLD” places us at 66%, which for a very small sample size is not unreasonable.
The hardware uses half of a Lily58 keyboard from Mechkeyboards, a regular keycap set in DSA and relegendable DSA keycaps from Signature Plastics (similar to lower profile keycaps from Mechboards).
The Lily58 uses QMK firmware, so I customising a new layout that follows along the same lines as the FrogPad – a primary layer, a secondary character layer (green), a symbol layer (pink), a function layer (orange) and a “secondary” function layer (green + pink).
I’ve named the layout “Frogger”.
See more about the build and use in the blog post here.