# Sudoku Help - Keyboard

Here's a page from the extensive help system for Sudoku Dragon. It is available as a help screen when running the program. To get the full picture Download our Sudoku Dragon and see the screen in its proper context.

Our menu and toolbar page lists all the Sudoku playing commands that are available from the program menu and toolbar. All the most frequently available actions are also available at the touch of a button - from the keyboard.

## Selecting a square

To select the Sudoku grid press TAB until one of the cells shows a flashing underline. You can also select a square by clicking the mouse on a square.

## Moving around the grid

The arrow keys (up, down, left and right) move by one Sudoku square in the corresponding direction. These only operate when a grid square is already selected. The page keys (Page up, Page down) move by one region up or down. If you use the control CTRL key at the same time it will move horizontally by a region rather than vertically. Home takes you to the top left square while End takes you to the bottom right.

## Setting the contents of a square

To set the value for a Sudoku square you must first select the square and then just use the appropriate key '1' to '9'. If you have Number lock (Num Lock) enabled you can assign a value with the number pad keys. You can also use the mouse wheel as an alternative way of allocating a value to a square.

## Clearing the contents of a square

Use the Delete key or Space to set the currently selected square as unallocated again.

## Setting Tentative Possibilities and Impossibilities

For more difficult puzzles, many Sudoku puzzlers will want to mark possibilities on squares. You can do this simply and easily by selecting an unallocated square and then pressing down control SHIFT key at the same time select the appropriate key '1' to '9' for the possibility you want to set. The possibilities are shown as small numbers (or letters) at the bottom of the square. To set a impossibility use the CTRL key at the same time and the number will be shown with reversed colors. To clear all the possibilities for a square press Delete. You can set all possibilities to be the same as the automatic possibilities by pressing F8 or Edit | Set Auto Possibilities. The setting of possibilities is remembered so the program can selectively Undo and Redo them if you find you need to change your mind later.

## Analyzing Possibilities

The possibility bar lets you quickly see what is possible to assign and where. You can use it by clicking on the symbols in the toolbar or by using ALT key with a number '1' to '9' to select a possibility option. If the possibility is already chosen this will clear the possibility display. To switch on all possibilities use the F4 function key. A highlight option is provided that shows the number of squares remaining.

## Keyboard Commands

Here are all the available keyboard commands :

 Key Command F1 Display help information F3 Hide the side panel F4 Show/hide computed possibilities for all values 1..9 F5 Show details for currently selected square F6 Switch automatic display of possibilities on or off F7 Clear all possibilities in current square F8 Set your marked possibilities to match automatic possibilities for the current square F9 Give a hint to help solve the puzzle F10 Show the current status of the game F11 Show possibility analysis for the current square F12 Automatically allocate an 'easy' to solve square CTRL+Z Undo the previous square allocation ALT+Back Undo the previous square allocation CTRL+SHIFT+A Redo the previously undone square allocation CTRL+SHIFT+N Generate a new puzzle CTRL+SHIFT+O Open an existing puzzle file CTRL+SHIFT+P Print the current puzzle CTRL+SHIFT+S Save the current puzzle SHIFT+1..9 Set or clear possibility for 1..9 (if using numbers) SHIFT+A..T Set or clear possibility for A..T (if using letters) CTRL+1..9 Set or clear impossibility for 1..9 (if using numbers) CTRL+A..T Set or clear impossibility for A..T (if using letters) ALT+1..9 Show/hide possibilities for 1..9 (if using numbers) ALT+SHIFT+A..T Show/hide possibilities for A..T (if using letters) SHIFT+F1 Set current square background to marker color 1 SHIFT+F2 Set current square background to marker color 2 SHIFT+F3 Set current square background to marker color 3 SHIFT+F4 Set current square background to marker color 4 SHIFT+F5 Clear square background marker color Pause Temporarily pause the game timer