Downloading and Running the Executable twosquare.exe  

Create a new folder in a location you can find easily, called CryptoPrograms or 
something similar that you will easily recognize. Create another folder inside 
this one for the cipher type, e.g., TwoSquare.  Now download the executable 
twosquare.exe into this folder.  You will also need to place a con in this 
folder, as a text file.  This file should consist of the con itself as a 
continuous string with no spaces, and the tip in uppercase letters on the next 
line.  You can start with the sample con file available for download from the 
same Computer Column folder on the ACA website that you got the twosquare.exe 
file. For example, the sample con for the TwoSquare cipher is called 
E22JA2008.txt.

To run the program, double-click the executable, and a new window should open.  
It will give the name of the program and ask for the file name of the con.  
Before going further, I suggest that you customize the window as follows:

1.  There is an icon just to the left of the title at the top left of the 
window.  Clicking on this reveals a drop-down menu.  Select the Defaults option.  
This opens another window called Console Windows Properties, which has 4 tabs.  
Change nothing in the General tab.
2.  Click on the Font tab and choose Lucida Console, whose letters are easy to 
read than the other choice.
3.  Click on the Layout tab.  Increase both the window width and screen buffer 
width from 80 to 90, giving a slightly wider window.
4.  Click on the Colors tab.  Change the screen background from black to white 
and the screen text from white to black by clicking on the appropriate radio 
button and then on the desired color square.
5.  When you have finished making the changes, click OK.

These changes doen't take effect until after the window is closed and re-opened.  
To make the changes immediate, select Properties in the drop-down menu and make 
the same changes.

You can make the window longer by dragging down on the lower right corner of the 
window. At the correct mouse position, a double-headed arrow control should 
appear.  You can't make the window wider using this control.

After customizing the window, go back to the program window, enter the name of 
the con file.  If you made the con file using Notepad or another text editor, it 
will show up in the folder with the name you used when saving it.  IMPORTANT: 
For these programs you must add the .txt extension when typing in the name.  
When the tableau comes up, proceed to solve the con, following the directions 
given by the program.  All steps can be undone by entering 0 when it is given as 
an option.  Quitting the program is accomplished by entering -1 when it is given 
as an option. 

If at some point you want to print out the display, you will need to prepare the 
window to highlight the part you want to print.  To do this, follow these steps:

1.  Click on the icon at the top left corner of the window and mouse down to 
Edit.  
2.  A second menu opens; select Mark.  
3.  Now use the mouse to highlight the portion of the window you want to print.  
This is done by selecting the area you want just as in a word-processing 
document.  
4.  Open the drop-down menu again, mouse down to Edit, and select Copy in the 
second menu.  
5.  Open a new document in Notepad.  
6.  In Notepad's Edit menu select Paste.  The part of the window you highlighted 
should now appear in this Notepad document, and you can print it.

When you are finished solving, enter -1 as directed by the program.  The 
solution will be written to a text file called <conname>sol.txt, which you can 
look at later with Notepad by double-clicking it.

Compiling the Pascal source file TwoSquare.pas

To create your own executable, you must have the FreePascal Compiler on your 
computer. For Windows, download it from www.freepascal.org/down/i386/win32-
ftp.freepascal.org.var.  To compile, open a Command Line window, navigate to the 
folder containing the source file TwoSquare.pas, and type fpc twosquare.  This 
will produce the executable twosquare.exe.  To run, double-click the executable.

Solution Hints

The reversed cipher is often helpful in finding fragments of words or high-
frequency digrams in the solution.  In the example con, E22JA2008.txt, check out the 
first 3 digrams for possible word fragments (before, you).