Manipulation of the playing grid is achieved either by using the mouse (or trackpad) or by using the keyboard.
Move playing grid cursor
Use the mouse (trackpad) or the keyboard cursor keys (Arrow keys).
The selected cell is marked by a rectangular coloured line and the corresponding row and column clues are highlighted.
Mark a cell filled
Left click or F
Mark a cell empty
Right click or E
Mark a cell unknown
Left double click or X
Mark a cell as an undo point (only while solving)
M
Undo to last marked undo point (only while solving)
L
Mark a block filled/empty/unknown
Position cursor at one end of block
Hold down the corresponding button/key
Move cursor to end of block
Release button/key.
Increase/decrease font size (and thereby the size of the whole window)
Press Ctrl+ to increase font size or Ctrl- to decrease it. (There are also toolbar icons for this).
To determine the freedom of a row or column
Hover the cursor over the clue. A tooltip appears giving the required information. This relates to the whole row or column and is not affected by any empty or filled cells.
Many of the menu/toolbar functions have accelerator keys. These are displayed in the menus:
Ctrl N - New puzzle
Ctrl O - Open (load) puzzle
Ctrl S - Save puzzle
Ctrl Q - Quit
Ctrl Z - Undo
Ctrl Y - Redo
Ctrl + - Increase font size
Ctrl - - Decrease font size
Shift S - Show solution
Shift W - Show working
Shift I - Show incorrectly completed cells
Shift R - Restart
Shift P - Pause timer (press Close button in dialog to continue)
Shift H - Get hint
Shift C - Use computer solver
Shift G - Generate random pattern
Shift E - Edit puzzle information and clues