Resco Sudoku for Palm OS: Manual

Online manual

1. Screen elements

Main board

9x9 board with fixed digits (usually black) and empty fields that may contain

Filled values (large digits in distinct color - usually blue)
Pencil marks (candidates) written in a small font.

Side keyboard

Contains digits 1-9 and serves as a keypad. In some help modes only allowed digits are shown, while the remaining cells are empty.

Cursor

Usually a yellow square located either on the main board or on the side keyboard - depending on the selected input method. Cursor can be moved with arrows or through a pen tap.

Timer

Timer measures the elapsed game time. Tapping the timer causes a pause. Another tap (or center button press) and you can continue.

? icon: How Am I doing?

Press this icon to see whether you made some mistakes. If you are creating a game, this icon will tell you whether the puzzle is valid etc.

< — icon (Back)

Use to undo the last change, whether it is a move or a change to the pencil marks.

3 mutually exclusive mode icons

Inputmode icon selects the input method, i.e. it has 2 states: -- "Grid" (Cell-then-number input method) -- "Side keyboard" (Number-then-cell input method) The states are toggled using repeated pen taps.
Pencil icon sets the pencil mark mode (pencil marks are written in a small font)
Eraser icon serves for clearing the selected cell.

Long tap *) on any of these icons displays a tooltip hint.

*) Long tap: Tap the icon and keep the pen pressed for a second. Long tap is also used for other reasons, e.g. opening the digit selection dialog.

2. Tutorial

This chapter contains will introduce you to using Resco Sudoku through a series of exercises.

2.1 Basic program control

A. Generate a new game:

Select Main menu > New > Very Easy.

B. Options

Select Main menu > Tools > Options

The top 4 options influence the help you receive during the solving process and we'll explain them later.

The bottom 2 options let you select the font combination you like at most. Switch on 'Auto Pencilmarks' and test various combinations to find the one that best suits to you the best.

C. Auto-save

Quit RSudoku and restart it. The game will resume in the state where you left. (You will see later that even the Undo/Redo features will work as if the playing was not interrupted.)

2.2 Input methods

There are various ways how to enter the digits and the preferences vary among the players. Here is the list of possible methods:

A. Long tap on a cell,
that does not contain a fixed digit, opens the digit selection dialog.
As a reaction either tap on a suitable digit or cancel the dialog by tapping somewhere outside the dialog area.

B. The same can be achieved using the keyboard
(Inputmode icon must show the "Grid" image!):
Navigate the cursor to an empty cell and press the center button.

To enter a digit:
Move the cursor with arrows to the desired digit to the desired field and press the center button.

To cancel:
Use Up or Down arrows to "navigate outside" of the dialog.

C. Pen: Number-then-cell method ("Sticky digits")
This method is switched on when the Inputmode icon shows the "Side keyboard" image.

In this mode:

The side keyboard has a cursor that can be moved with the arrows or through the pen.
The cursor on the main board reacts only to the pen taps.

To enter a digit:

Select a proper digit on the side keyboard.
Tap a cell on the main board.

This method is very fast with 2 hands:
One hand selects the digits using 5way, while the other hand controls the pen.
You may like it mainly in the initial phase of solving a new puzzle.

D. Pen: Cell-then-number method
Make sure the Inputmode icon displays the "Grid" image and do this:

Tap an empty field on the main board,
Tap a digit on the side keyboard

2.3 Using Auto-pencilmarks

In the RSudoku Options dialog switch on 'Auto Pencilmarks' and switch off the remaining help options.
Generate a new game. (Take some easy level.)
Empty cells will be filled with pencil marks (candidates) written in a small font.
Look for fields containing just 1 candidate.
(This means that all remaining digits are excluded because they are found in the same row, block or column.)
Do a long tap on such a field - this will set the single possible value.
(This procedure is a shortcut for opening the digit selection dialog and selecting the value.)
Notice that after setting the value pencil marks in the surrounding cells (row/column/block) are adjusted to account for a new known value. This is what the auto pencilmarks serve for.
Repeat the last step until you fill all empty cells.
(This will not work on higher levels, of course.)

This is kind of cheating, for sure, and a different game. But it is still fun and it helps to better understand the mechanics of Sudoku.

Notice also, that because you used help by solving, your solution time is penalized by adding an extra time. This penalization was chosen so that a really good Sudoku player will do better without any help. (More about the penalization later.)

The same exercise can be made with the keyboard as well, but the results are worse.

2.4 Using "Forbid block conflicts"

In the Sudoku Options dialog switch on 'Forbid block conflicts' and switch off the remaining help options.
Select Cell-then-number input mode (the Inputmode icon must display the "Grid" image)
Generate a new game. (Take some easy level.)
Browse with the cursor around the board and analyze the behavior of the side keyboard.
You will notice that it shows only a few digits — actually the same digits as would the auto-pencil-mark mode display (candidates).
Look for fields with just 1 candidate and do a long tap on such a field (or center button press) to fill this value.
Repeat the last step until you fill all the empty cells.
(This will not work on higher levels, of course.)

Again cheating, but again funny. (Especially good to play with one hand.)
After some training you will get really good times, but be aware that real Sudoku masters will do better without any help, because your time includes the help penalty.

3. Other techniques

Hints

If you can't find the next move, you may ask for a hint.

In turn RSudoku selects one row, column or block and marks it in a green color. It is one of the elements, where a unique move is possible.
If you ask for a hint again, RSudoku will mark just one cell, where a unique move can be done.
If you ask for a hint 3rd time, RSudoku will fill the cell with a value.

Notice that the hints use the same logic as the auto pencil marks. Hence, it often happens by really difficult puzzles, that no hint is found. This is done with purpose, because otherwise the game would lose on its magic on high levels.

Hide Ready Digits

With this option the digits that are used-up (i.e. filled in 9 cells) are removed from the side bar. Notice that this is just a visual effect and the field itself (although empty) is active further on.

Other bug tracking methods (see Options dialog)

'Flag mistakes' option will mark in red any incorrect value you type in process of solving.

'Flag duplicates' will mark red a column, row or block where 2 equal digits are found. Notice that every duplicate is a bug, but there are mistakes that are not be caused through using a duplicate value.

Undo/Redo

These features work the standard way by moving the game to the past state and back. This concerns not only the input of the digits, but also the changes to the manual pencil marks.

However, as mentioned earlier, Undo does not preserve changes done to the automatic pencil marks.

Removing values

Erasing with a pen:

Set on the Eraser icon
Tap a cell

This action clears the cell content completely.

Same effect with the keyboard:

Select the field
Enter the value 0 or press spacebar.

Erasing a single pencil mark: Edit pencil marks in a standard way.

Save/Restore state

Really difficult puzzles use to contain places where you can spent long time until the right move is discovered. In such cases you can do better with a guess. That's where Save/Restore state menu commands come to help.

'Save state' command will remembers the current game state. You can continue solving and if you arrive to a dead end, you can use 'Restore state' to return to your "choice point".

Notice that the saved state is remembered also when you quit RSudoku.

4. Pencil marks

4.1 More about pencil marks

Automatic pencil marks are generated directly from the Sudoku rules, i.e. this process is repeated for each empty cell:

At the start the cell can contain digits 1-9.
Then the cell row is scanned and digits found there are excluded.
Then the same is repeated for the cell column and cell block.
What is left represents the automatically generated pencil mark.
(Notice that the leftover cannot be empty - this would mean an invalid puzzle and is against the rules.)

Of course, a human is able of more complex considerations and in an extreme case (a genie) one could directly see the results.

Most of us are normal people who can relatively easily perform the automatic checks, but have problems to remember more than a few results.

As you will later find, on higher levels you soon get into a situation when there is no one field with only one pencil mark.

This is the limit of the automatics and the place where the human thinking has to take over.

Let's suppose that the automatically generated pencil marks look like this:

Field	Possible values
A	12
B	12
C	123
D	1245

It is not too difficult to deduce that the fields A,B will contain digits 1,2 (the order is not known) and that

the field C contains value 3
the field D has either 4 or 5

While the first fact can be exploited immediately through entering the value 3, the second fact should be memorized for later use.

In other words, you would need the following:

Field	Possible values
A	12
B	12
C	3
D	45

That's where manual pencil marks come to help.

4.2 Manual pencil marks

By solving difficult puzzles you will soon find out that automatic pencil marks are not intelligent enough and that you are able to dig more information. The previous chapter showed an example,

To enter (or edit) your own pencil marks:

1. Set on the pencil icon.
2. Select the desired cell.
3a. Tap suitable digits on the side keyboard, or
3b. Open the digit selection dialog and modify its state by tapping suitable fields. (Cannot be performed with a keyboard.)

Notice that entering the same value 2nd time works like an eraser.

To clear pencil marks: With a pen:

Set on the Eraser icon
Tap the cell where you need to clear the pencil marks

With the keyboard:

Enter the value 0 or press spacebar.

Auto-update Pencilmarks
(Since v1.30) This option helps to maintain manual pencil marks. If it is switched on, then whenever you input a new value, all manual pencil marks that are in conflict with the new value (i.e. the same pencil mark in the same row, column or block) are cleared automatically.

4.3 Other pencil mark techniques

Main menu contains options to generate (fill) or remove (clear) all pencil marks.

Tip: Some users find these options so useful, that they assign them to suitable HW keys. They spent most of the time solving without the pencil marks and call them for help just occasionally by using selected shortcuts.

Automatic pencil marks can be edited, too. RSudoku will respect the values that you removed (who would add a value to the auto-pencil-marks, of course), but only as long as you do not use Undo: Undo newly redefines the auto-pencil-marks and your changes are lost.

5. Sharing and storing

5.1 Quick save

RSudoku always restores the state from the last game played. This concerns all game attributes - fixed grid, filled digits (moves), pencil marks, game time, penalties and undo history.

5.2 Game State

Use it as a kind of choice point when you come to a difficult place and want to inspect alternative moves. Saved state stores all game attributes except the undo history.

The saved state is bound to the game that is being played and is lost when you start a new game.

The game state can be saved/restored using the main menu commands.

5.3 Save to a card file

You can save the full game state to RSudoku internal format or save just the puzzle itself (fixed cells) to several foreign formats. Save/load operations are realized via RSudoku main menu commands.

RSudoku format stores all game attributes except the undo history, i.e. it is suitable for storing intermediate game states.

The disadvantage of this format is that it is supported only by Resco Sudoku. (Both Palm and PPC versions.)

RSudoku supports formats used by a number of popular Sudoku utilities. At present only simple text formats are supported that describe solved puzzle in an easy readable form. (This may change in the future) The disadvantage of these formats is that they do not allow for storing the intermediate game states.

Examples of the text formats:

*-----------* 
|..8|..6|4..| 
|.67|.1.|.2.| 
|1..|...|.8.| 
|---+---+---| 
|.8.|9..|..5| 
|...|.6.|...| 
|3..|..8|.6.| 
|---+---+---| 
|.2.|...|..1| 
|.9.|.7.|63.| 
|..5|4..|8..| 
*-----------*

[Puzzle] 
..8..64..
.67.1..2.
1......8.
.8.9....5
....6....
3....8.6.
.2......1
.9..7.63.
..54..8..

Notice that while the Save dialog explicitly lists available formats, the Load dialog uses a heuristic approach in decoding and supports thus a wider selection of foreign formats.

RSudoku stores the data in the /Palm/Programs/RSudoku directory on any mounted drive that the user selected. (A card, built-in drive etc.)

To move the external Sudoku files into that folder you will need some file manager, e.g. Resco Explorer.

5.4 Sharing puzzles via Game ID

This tool allows you to recreate an identical puzzle on another Palm PDA. To find your ID use the 'Get Game ID' menu command.

If you now restart RSudoku and use Menu > New > Load by ID and type the same string (case independent), your puzzle will be regenerated.

You can use it e.g. to organize a competition.

Notice that the Game ID is recognized only by Resco Sudoku, i.e. other Sudoku solvers that support the Game ID concept use incompatible format.

7. Shortcuts

Treo users have an advantage, as they can use a number of keyboard shortcuts, which can speed up the play:

i
p
q
?
+
-
*
Back
Space

Toggles the input mode
Pencil marks mode
Pause
How am I doing?
Save state
Restore state
Options
Undo
Clear number

An additional possibility offers the Keys dialog, where you can assign program functions to the standard Palm hardware keys. Notice that the keys are referred to as HW1..HW4, where the numbering goes from left to right.

This mapping is deactivated when the game is paused. This makes it possible to easily return to the standard key functions and make e.g. a phone call or open the calendar.

8. Time counting, statistics

The game timer provides a quantitative measure for the player comparison.
(Since v1.30 the timer can be switched off using the Options dialog.)

However, a simple time counting is not adequate, as it does not consider received help.

One possibility to handle this is to exclude all the results achieved with some help. (websudoku.com) This is certainly possible, but limiting.

Instead of that, we decided to measure received help by introducing the time penalties.

Achieved game times are collected into the statistics. Statistics are organized by levels and can be accessed at these occasions:

During a pause you see basic stats for your level
Similar output is available after you complete a game
Finally you can use the Statistics dialog (main menu), which additionally offers cleaning of the statistics by level.

9. Time penalties

Penalties range from 0 for Very Easy puzzles to the highest values on the Expert level. Following list of penalties enumerates how many seconds are added if you use particular help tool.

Penalties for Auto Pencilmarks:

VeryEasy 0
Easy 180 (3 min)
Medium 240 (4 min)
Hard 300 (5 min)
VeryHard 360 (6 min)
Expert 360 (6 min)

Penalties for Forbid Block Conflicts:

2/3 of the Auto Pencilmarks penalties

Penalties for Flagged Mistake or Duplicate (bugs):

VeryEasy 0
Easy 15
Medium 30
Hard 60 (1 min)
VeryHard 90 (1.5 min)
Expert 120 (2 min)

Penalties for hints:

Each hint step is equivalent to 1/3 of the bug penalty.

? icon:

Error message counts as a mistake, a positive message incurs no penalty.

Penalties are setup so that:

A beginner will do much better using the help tools
The best times are achieved by advanced players who do not use any help tool

Time penalties might be adjusted in the future as we collect more relevant data.

10. Creating own puzzle

It happens from time to time that you want to solve a puzzle that was published elsewhere.

To do so:

Select Menu > New > Create Own
Optionally setup suitable help options, e.g. 'Flag mistakes' (this time no penalties are involved)
Enter the individual values into proper positions until the puzzle is ready
Press the ? icon to verify that the puzzle is correct
To complete the puzzle select Menu > Game > Play

Now you can play as usually.

There is just one difference against the generated games: Created puzzle does not have the game ID and hence no easy sharing is possible.

11. Skins

RSudoku installer — RSudoku.prc — is a relatively small file that contains just the standard GUI elements (buttons, colors, background).

Those who want more attractive screens can install one or more RSudoku skins. Skins are distributed as standalone prc files (e.g. Atlantic.prc) and are installed in the standard way - through Hotsync.

For the skin selection/deletion use the Main menu > Tools > Skins command.

Since v1.30 the skins can be installed either to RAM (the only possibility in the older versions) or to the card. This decision is to be made using the Skins dialog.

Resco Sudoku (v1.30.3)