Visibility
- Board. Every piece. A move waits until the file and the rank have sounded.
- Fading. The same board. Untouched pieces sink after a few seconds.
- Echo. A dark grid. Landing lights the nearby squares, then they close.
- Sound. The position is put away. The keys stay.
- Pure. No letters and no counted taps. Pitch only, and faster.
a1
Piece, then file, then rank.
1 · Rank
2 · File
3 · Piece
Promote the pawn