You can design your own regular repeating cell patterns to play in Crossmines. To do this, you should be familiar with a text editor, and be prepared to do some thinking to work out how your patterns will tessellate. The description below is from the ReadMe.txt file included in the Patterns/ folder.

Creating your own patterns

Crossmines looks for patterns in the patterns\ sub-folder, in the location of the Crossmines.exe file, usually in c:\Program Files\comp-sci\Crossmines\. Each .pat file is a pattern. This file can be edited in a regular text editor (including Notepad.exe), and the required format of this file is described below.

The format of the .pat files

Line-by-line, the .pat file is arranged as follows:

Line	Field	Example data
1	Registered ID	3
2	Author	John Valentine (comp-sci)
3	Title	4 and 8 (Squares)
4	Description	All squares. Some have 4 neighbours, some have 8 neighbours.
5	Rec Field Size X	19
6	Rec Field Size Y	19
7	Large Grid Size X	6
8	Large Grid Size Y	6
9	Repeat Size X	5
10	Repeat Size Y	5
11+	Large Grid Line 1	...11.
...	Large Grid Line 2	22011.
...	Large Grid Line 3	22330.
...	Large Grid Line 4	.03344
...	Large Grid Line 5	.55044
...	Large Grid Line 6	.55..0

Characters used in the Pattern Grid

The Pattern grid defines the shapes of the cells in the Crossmines minefield. In the above example, you can see a block of 3s (2 wide, 2 high). When numbers are grouped together like this, it means that a larger cell is formed from squares having the same number.

You will need a different number for each cell within the pattern. For cells bigger than 1 square (as all the cells are in the above example), start with the number 1. After 9, start at A, and continue to Z. This gives you 36 cells, which should be enough.

You can use other characters for other purposes:

0	Use this to signify a cell that is a single square (1×1 in size). You can use several 0 squares, and each will become a different cell.
.	The pattern is 'stamped' across the minefield, and full stops . are used to denote 'transparency', where the opposite edge of the pattern will interlock. The 'Repeat Size' fields set the spacing of the 'stamping' across the minefield. Where shapes do not fully tessellate, holes will be left.
-	Use this to signify a hole. Holes play no part in the minefield, are simply inaccessible and give no information to the player. These holes are the same as the holes created by the New Game option Holes.
#	Denotes a Bridge. This helps overcome a shortcoming of the square geometry of Crossmines. When the player hovers over a cell adjacent to a Bridge, the Bridge will always be included as part of that cell. Note: Bridges are not implemented in version 1.0.1 of Crossmines.